Over three years on this professional networking platform, LinkedIn has become an important communication channel for Marquis Intelligence. Today, the company’s page has more than 2,250 followers.

According to LinkedIn analytics, Marquis Intelligence has achieved notable results compared with a selected group of international companies operating in the same or related fields.

From Engineering Experience to Digital Transformation

Marquis Intelligence has been operating since 1992. More than three decades of designing, implementing, and maintaining ventilation and air purification systems form the foundation of the company’s technical expertise.

However, having knowledge and making it accessible are two different things.

The digital transformation of Marquis Intelligence’s communication began in 2022, when the company launched a new website to mark its 30th anniversary. This was followed by the development of a technical blog. The Serbian business news platform eKapija also covered this strategic step in an article about Marquis Commerce’s digital transformation.

The idea was simple: preserve experience, explore technical topics, and make knowledge available beyond the company’s immediate business contacts.

The next step was the launch of the company’s LinkedIn page in 2023. Its Facebook page became active the following year.

For a small, specialised engineering company without a large marketing budget, digital communication created new opportunities to establish a professional presence.

Rather than competing through the volume of promotional activities, Marquis Intelligence chose to focus on consistency, technical relevance, and content quality.

Why LinkedIn?

Because knowledge becomes more valuable when it is shared.

LinkedIn provides opportunities to connect directly with engineers, architects, equipment manufacturers, researchers, investors, and other professionals around the world.

From the outset, most content was published in English, allowing the company to reach an international professional audience.

What Does Marquis Intelligence Write About?

Marquis Intelligence’s approach to LinkedIn content goes beyond presenting products and completed projects Its posts cover scientific research, modern technologies, standards, the health effects of air pollution, historical events, and interesting facts from the world of air.

Naturally, practical engineering solutions, project references, and case studies also play an important role.

This diversity is intentional. Air connects engineering, medicine, energy, architecture, environmental science, and everyday life.

Marquis Intelligence’s Editorial Approach on LinkedIn

Marquis Intelligence’s LinkedIn posts often combine several distinctive elements:

• Educational approach: Complex technical subjects are explained clearly and accessibly.
• Engaging opening: A question, an unexpected fact, or a comparison encourages readers to think.
• Engineering-based reasoning: Statements are supported by technical expertise, scientific research, and practical experience.
• Professional interaction: Comments and discussions provide opportunities to exchange ideas and experiences with experts from different fields.

One example is a Marquis Intelligence LinkedIn post about smart buildings and ventilation which connects everyday building automation functions with the importance of controlled ventilation and indoor air quality.

We Plan, Publish, and Measure Results

Marquis Intelligence’s presence on LinkedIn is not the result of occasional posting.

The company prepares annual marketing plans that define objectives, thematic priorities, and publishing schedules. Detailed content records are maintained, while performance is analysed using impressions, reactions, comments, shares, clicks, and other metrics.

Under the leadership of Gordana Blagić, Technical Director and Co-owner, the Marquis Intelligence team approaches professional communication as part of a broader strategy to showcase the company’s knowledge, experience, and business achievements.

This approach ensures that the content is directly grounded in engineering practice, technological expertise, completed projects, and an understanding of market needs.

In addition to the company’s LinkedIn page, Marquis Intelligence employees use their personal profiles to build professional connections, share technical content, and participate in discussions. This extends the company’s communication through direct professional relationships, contributing to greater visibility and knowledge exchange.

What Do the Results of Marquis Intelligence’s LinkedIn Presence Show?

According to LinkedIn analytics for the 365-day period ending in October 2026, Marquis Intelligence gained 549 new followers and received 253 comments. The company ranked first in both metrics among ten companies in the selected comparison group.

The same leading positions were recorded over the 90-day period, with 243 new followers and 63 comments.

The comparison group also includes internationally active manufacturers and companies with significantly greater organisational resources.

These results demonstrate the effectiveness of the chosen approach in terms of audience growth and engagement. However, the objective is not simply to increase follower numbers.

It is to establish relevant professional connections and strengthen the company’s recognition over the long term.

SEE ALSO: Gordana Blagić: 20 Years at Marquis Commerce

LinkedIn as Part of an Integrated Knowledge Base

LinkedIn is not a standalone communication project. It is part of Marquis Intelligence’s broader digital strategy.

Over four years, the technical blog has developed into a library containing more than 100 articles. An FAQ knowledge base has also been developed, while case studies have become an important way of documenting practical engineering experience.

SEE ALSO: The Blog as an Air Knowledge Repository

Each format serves a different purpose. The blog enables in-depth exploration of technical topics. The FAQ knowledge base provides structured answers to frequently asked questions.

Case studies document specific challenges, implemented solutions, and achieved results.

LinkedIn helps distribute this content and connect the company with the wider professional community.

In this way, engineering experience, technical writing, digital visibility, and professional communication become interconnected elements of the company’s development.

Three years of successful LinkedIn presence represent both an outcome of this strategy and a foundation for its continued development.

For Marquis Intelligence, sharing knowledge is not a substitute for engineering practice. It is a way to make practical experience more widely applicable and to build professional relationships beyond the boundaries of the local market.

This article is part of a series highlighting the activities and business achievements of Marquis Intelligence.
Document No.: MI-PROM-26.024 – Marquis Intelligence on LinkedIn: Three Years of Knowledge Sharing and Growth.

The post Marquis Intelligence on LinkedIn: Three Years of Knowledge Sharing and Growth appeared first on Marquis Intelligence.

However, the project involved much more than installing an electrostatic precipitator. It also included continuous particulate emission monitoring, improving the plant’s energy efficiency by recovering heat from flue gases, and collecting and conveying the separated ash.

Another major challenge was integrating large new equipment into an existing plant. This required partial demolition of the building and associated construction work.

Finally, an independent accredited laboratory had to verify the plant’s performance through emission measurements.

Who Did Dijamant Entrust with the Project?

Dijamant entrusted the engineering design and execution of the project to Marquis Commerce, Belgrade.  Working with a partner, the company delivered the complex system on a “turnkey basis”.

In other words, Marquis Commerce was responsible for the entire process: from developing the technical solution and detailed engineering designs to equipment supply, installation, and commissioning. The project documentation comprised the main civil engineering, electrical engineering, and mechanical and process engineering designs.

The contract signing received media coverage. A recording of the event by KTV television is still available on the Marquis Intelligence YouTube channel.

Sunflower Husks as Fuel

Sunflower processing generates substantial quantities of sunflower husks. At Dijamant, these husks were regarded not as waste, but as a valuable resource. This energy-rich biomass was used as fuel to generate process steam.

Boiler K5, manufactured by Minel Kotlogradnja, had a steam generation capacity of 25 t/h and could operate on either natural gas or sunflower husks. When operating on biomass, natural gas was used primarily for start-up, until stable sunflower husk combustion had been established.

Using sunflower husks made it possible to replace approximately 70% of natural gas consumption. The project presentation assumed a daily consumption of approximately 84 tonnes of sunflower husks, with an energy benefit equivalent to saving around 1,600 Nm³ of natural gas per hour.

The economic justification for using biomass as fuel was clear. The problem was particulate matter emissions.

Particulate Emissions 32 Times Above the Limit

Measurements carried out in 2003 in the flue gas duct of boiler K5 showed a total particulate matter concentration of  1,630.04 mg/Nm³, with the boiler operating at a steam generation rate of 11 t/h. The applicable emission limit at the time was 50 mg/Nm³.

The measured concentration was therefore more than 32 times the permitted limit, resulting in the shutdown of the boiler. The problem was no longer purely environmental. Shutting down the boiler also meant losing the opportunity to use biomass as a virtually free fuel in place of substantial quantities of natural gas.

The solution therefore had to meet process, environmental, and economic requirements simultaneously.

Electrostatic Precipitator at Dijamant – Price or Technical Challenge?

Several serious suppliers competed for the project. The decisive factor in selecting the supplier was not simply the equipment price, but its technical characteristics and the manufacturer’s experience. Selecting an electrostatic precipitator to clean flue gases generated by sunflower husk combustion represented a significant technical advance, extending beyond the local context.

Sunflower oil production processes differ in how the raw material is initially prepared. Most producers do not dehull sunflower seeds. As a result, sunflower husks are not separated as a distinct process by-product. Because of their low bulk density, separated sunflower husks present particular challenges in storage, conveying, and subsequent use. Boiler plants designed to burn this biomass must therefore be adapted to its specific characteristics.

This is what made the application of an electrostatic precipitator to flue gases from sunflower husk combustion particularly distinctive.

Sunflower husks cannot simply be treated as equivalent to wood or wood pellets. Their structure, moisture content, and organic constituents affect combustion and the properties of the resulting particles. The analysed sunflower husk composition included, among other constituents, approximately 3% oil.

Why Was an ESC Umwelttechnik Electrostatic Precipitator Selected?

The selected solution was supplied by the German company ESC Umwelttechnik GmbH. An important advantage was the experience of its owner, Jürgen Fischer, with biomass of similar characteristics, including rice husks. Other solutions under consideration relied more heavily on experience with woody biomass.

For a plant of this type, nominal airflow capacity and declared collection efficiency are not sufficient selection criteria. Engineers must understand the actual process that generates the flue gas. That process determines the properties of the particles and other pollutants and, consequently, the appropriate technical solution.

Marquis Commerce as Engineering Designer and System Integrator

As already noted, the project scope extended far beyond the electrostatic precipitator itself.

The proposed system included a new waste heat recovery heat exchanger, an ESC Umwelttechnik electrostatic precipitator, a flue gas particulate monitoring system, an ash discharge and conditioning system, connection to the existing induced-draft fan, new flue gas ducts, piping, thermal insulation, maintenance access provisions.

Marquis Commerce prepared the project documentation through three coordinated engineering disciplines: civil, electrical, and mechanical/process engineering.

The project was therefore not simply a matter of installing an electrostatic precipitator between the boiler and the chimney. It involved creating a new, integrated process system in which all components had to function together.

Electrostatic Precipitator from a Reliable German Manufacturer

The electrostatic precipitator installed at Dijamant in Zrenjanin was manufactured by ESC Umwelttechnik, Germany, type 400/ESC/1 × 2 × 10 × 6 × 3.0.

The unit was designed for a flue gas flow rate of 33,100 Nm³/h, equivalent to approximately 50,000 m³/h under operating conditions. The design inlet particulate concentration was 6 g/Nm³, while the guaranteed outlet concentration was a maximum of 50 mg/Nm³.

The precipitator had two sections and ten gas passages. The specified collecting electrode area was 720 m², or 960 m² of developed surface area for the sigma-profile collecting electrodes. Each section had its own high-voltage power supply unit, with a nominal high voltage of 111 kV and a rated power of 15.54 kW per unit.

How the Electrostatic Precipitator Separates Particles

Inside the electrostatic precipitator, particles are first electrically charged in the corona discharge zone. The corona discharge is generated at the discharge electrodes installed in each of the ten passages between the rows of collecting electrodes. Under the influence of the electric field, negatively charged particles migrate towards the collecting electrodes, where they are separated from the flue gas stream.

A layer of collected particulate matter gradually forms on the collecting electrodes. The accumulated material is removed by a mechanical rapping system using hammers.

SEE ALSO: FAQ 2 – Marquis Intelligence Solutions

The design of discharge electrodes has changed significantly throughout the development of electrostatic precipitators. Early designs used thin wires and, later, serrated elements. These were more susceptible to mechanical damage and operational interruptions. Modern designs use rigid discharge electrodes with pointed emission elements, providing substantially greater reliability.

During operation, positively charged particles also accumulate on the discharge electrodes. These deposits are likewise removed by rapping.

All electrodes are cleaned through periodic mechanical rapping. The cleaning process is automated, and the rapping interval and frequency can be adjusted to suit operating conditions. At the Dijamant plant, the rapping interval was set to less than five minutes.

The electrostatic precipitator was also equipped with a system for optimizing electrical energy consumption.

Waste Heat Recovery from Flue Gases

Before entering the electrostatic precipitator, the flue gases passed through a new waste heat recovery heat exchanger. The unit was designed to handle approximately 50,000 m³/h of flue gas. It reduced the flue gas temperature from approximately 240–290 °C to 130 °C. The recovered heat was used to preheat demineralized water for the steam-generating boiler plant.

This arrangement recovered part of the thermal energy contained in the flue gases. At the same time, it provided suitable operating temperatures for the electrostatic precipitator and reduced the amount of heat discharged into the atmosphere.

Removing Ash from Flue Gas Is Not the End of the Process

Flue gas cleaning does not end when particulate matter is separated from the gas stream. After separation, both the collected particles and the cleaned flue gases continue through the system, but along different paths. 

The Path of the Collected Ash

When the electrodes are rapped, the collected ash falls into the ash collection hopper. From there, a system of screw conveyors removes it from the electrostatic precipitator. The project included a dry ash screw conveyor, an ash conditioning and moistening system, a conveyor for moistened ash.

Special enclosed containers were also designed to collect the separated ash and transport it away from the factory premises.

The Path of the Cleaned Flue Gases

Measuring Residual Particulate Matter in Flue Gases

After passing through the electrostatic precipitator, the cleaned flue gases flow through the flue gas ducts, past the monitoring station, and into the chimney.

At the advanced monitoring station, particulate matter concentration is measured directly in the flowing flue gas using laser-based measurement technology. More than twenty years ago, this was exceptionally sophisticated equipment.

In Engineering, Every Detail Matters

In an electrostatic precipitator, numerous design details directly affect reliability, collection efficiency, and service life.

Dedicated Ventilation for High-Voltage Insulators

The high-voltage insulators mounted on top of the electrostatic precipitator were provided with a dedicated ventilation system. The system supplied thermally conditioned and filtered air to prevent contamination and condensation on the insulators. Such conditions could otherwise lead to the formation of electrical leakage paths along the insulator surfaces.

Rounded Internal Edges of the Precipitator and Ash Hopper

The project demonstrated how details that may initially appear insignificant can influence the final result.

The internal geometry had to be designed to avoid areas where dust could accumulate unnecessarily. For this reason, the internal edges of both the precipitator housing and the ash hopper were rounded. This reduced the risk of collected ash accumulating and adhering in corners.

Thermal Insulation and Electric Heating Elements

Insulating the large precipitator housing and ash hopper presented a particular challenge. The insulation was installed on welded insulation pins, with special attention to minimizing thermal bridges. A flexible electric heating element was also installed beneath the insulation, following a serpentine pattern across the surface.

Its purpose was to help maintain the required surface temperature and prevent unwanted condensation.

Today, such a detail may seem like a logical part of the design. Two decades ago, however, finding a domestic company willing and able to install this type of specialized insulation on the precipitator and its large ash hopper was far from straightforward.

Details such as these often determine whether equipment that performs well in the design stage will also operate reliably under actual plant conditions.

Ash Conditioning and Moistening

Moistening the collected ash was an important part of ensuring its safe removal and transport. Adding water reduced the possibility of smouldering particles remaining in the collected ash, as well as the risk of fine dust becoming airborne again during handling and transport.

At the same time, the moistened particles tended to bind together. This reduced the loose, free-flowing nature of the ash and facilitated its controlled transport and disposal.

Trial Operation and Final Commissioning

During the initial trial operation of the plant, the monitoring equipment indicated very low particulate matter concentrations. However, during the first morning inspection, a sudden deterioration in performance was observed. The readings had exceeded the measurement range of the continuous particulate emission monitoring system.

An analysis of the operating procedures, together with discussions with the boiler plant operators, identified the cause. During the night, the operators had carried out steam sootblowing unusually frequently and for extended periods, exercising additional caution while operating the new equipment.

The increased moisture content of the flue gases caused ash to adhere more strongly to the electrodes, forming deposits. These deposits reduced the effective electrode surface area and impaired the performance of the electrostatic precipitator.

The operators received more detailed operating instructions. The electrodes were thoroughly cleaned by rapping, and the automatic rapping intervals were shortened. These measures improved electrode cleaning and stabilized system operation.

Following final commissioning, guarantee performance measurements were carried out.

Guarantee Measurements Confirmed Collection Efficiency

The project results were verified by the accredited laboratory A.D. Bio-ekološki centar, Zrenjanin. On 14 June 2006, the laboratory carried out emission measurements using the prescribed methods.

The measured mean particulate matter concentrations were:

• 17 mg/Nm³
• 23 mg/Nm³
• 32 mg/Nm³

The applicable emission limit at the time was 50 mg/Nm³.

Following the guarantee measurements and further optimization during operation, particulate emissions were reduced to below 20 mg/Nm³. In other words, compared with measurements taken before the electrostatic precipitator was installed, particulate matter emissions were reduced by more than a factor of 80.

A Significant Investment with a Short Payback Period

The technological part of the investment amounted to approximately EUR 750,000. Additional construction, reconstruction, and associated works increased the total investment to approximately EUR 900,000.

The techno-economic analysis assessed the value of the energy obtained by burning sunflower husks against the cost of alternative energy sources.

Based on the official industrial natural gas price at the time, the estimated payback period for the technological part of the investment was 88 operating days.

The analysis was also verified by comparing the energy equivalent of sunflower husks with the cost of the natural gas or electricity required to produce the same amount of energy. When the broader investment scope was considered, both approaches indicated a payback period of approximately 8–9 months.

In this case, environmental protection was not simply a regulatory compliance cost. The investment enabled the plant to continue using its own energy resource.

More Than Two Decades Later

More than two decades have passed since the project was completed.

After completion and the expiry of its contractual obligations, Marquis Commerce was no longer involved in the plant’s regular operational monitoring. In the meantime, the applicable particulate emission limits have become more stringent.

According to Predrag Nenin, Quality and Environmental Manager at Dijamant, the electrostatic precipitator continues to meet the current particulate emission requirements. This may be the most important long-term confirmation of the project’s success.

The system was not designed merely to comply with the 50 mg/Nm³ limit applicable immediately after commissioning. Further optimization and the achievement of concentrations below 20 mg/Nm³ provided an additional performance margin. This margin allowed the system to remain suitable for continued operation even after regulatory requirements became stricter.

A Project That Connected Two Professional Careers

On the client’s side, the project was managed by professionals directly responsible for investment projects, maintenance, and technical implementation at Dijamant.

Momčilo Ćuk, then Director of Investments and Maintenance, played a key coordination role throughout the project.

Other key representatives of the client included Sava Dutina and Gordana Petrović, now Gordana Blagić. They were responsible for supervising the electrical and mechanical installation works on behalf of the client during the electrostatic precipitator project.

After the project was completed, Gordana joined Marquis Commerce. As a licensed engineer for design and construction works, she continued working on the engineering and implementation of ventilation, air quality, and process engineering systems.

SEE ALSO: Gordana Blagić: 20 Years at Marquis Commerce

What Does the Dijamant Electrostatic Precipitator Project Demonstrate Today?

The Dijamant project demonstrates that successful industrial flue gas cleaning depends on more than selecting the right equipment. It also depends on how well the solution is adapted to the specific fuel, plant, and actual operating conditions.

In this case, the challenge was to enable continued use of sunflower husks as fuel, address exceptionally high particulate matter emissions, and integrate the new system into an existing energy plant.

The result was an electrostatic precipitator that reduced particulate matter emissions by more than a factor of 80, while achieving a remarkably short investment payback period.

More than 20 years later, according to confirmation from the plant operator, the same electrostatic precipitator continues to meet the applicable particulate emission requirements.

The long-term durability of the achieved results may be the strongest evidence of the project’s value.

References

1. Marquis Commerce d.o.o. Main Mechanical and Process Engineering Design for Addressing Particulate Emissions from Boiler K5, Book 3, Volume 1, Dijamant AD Zrenjanin, Belgrade, January 2006.
2. A.D. Bio-ekološki centar, Zrenjanin. Laboratory Test Report No. I 424, 19 June 2006, based on emission measurements carried out on 14 June 2006 in the common flue gas duct of boilers K4 and K5, Dijamant AD Zrenjanin.
3. A.D. Bio-ekološki centar, Zrenjanin. Laboratory Test Report No. I 502, 10 July 2006, based on emission measurements carried out on 4 July 2006 in the common flue gas duct of boilers K4 and K5, Dijamant AD Zrenjanin.
4. Petrović, G.; Janaćković, V. Addressing Particulate Emissions from Boiler K5 at Dijamant AD, Zrenjanin, by Installing an Electrostatic Precipitator. 33rd Conference Air Protection ’05, Belgrade, 2005, pp. 89–94. Bibliographic record of the National Library of Serbia.
5. Petrović, G.; Ćuk, M. “Installation of an Electrostatic Precipitator to Reduce Particulate Emissions from Boiler K5 at Dijamant, Zrenjanin.47th Oil Industry Conference “Oilseed Production and Processing”, Herceg Novi, June 2006. Uljarstvo, Vol. 37, Nos. 1–2, 2006.
6. Petrović, G. “Sunflower Husks as Fuel. 48th International Conference “Oilseed Production and Processing”, Herceg Novi, 11–16 June 2007.

This article is part of the Marquis Intelligence Grande Case Study (GCS) series, which documents projects distinguished by their technical complexity, implementation scope, measurable results, or long-term significance.

Document No.: MI-GCS-001.26 – Grande Case Study: Electrostatic Precipitator at Dijamant, Zrenjanin

The post Grande Case Study: Electrostatic Precipitator at Dijamant, Zrenjanin appeared first on Marquis Intelligence.

These were not the years when the first air pollution laws were introduced. However, this period marked the beginning of a different approach. Air pollution was increasingly viewed not simply as a local problem involving smoke, soot, or individual industrial emissions, but as a public health issue requiring action by municipal, state, and national authorities.

Three Cities, Three Continents, Three Windows into Modern Air Pollution Regulation

London, New York, and Tokyo were among the most striking examples of the period. They faced different sources and levels of pollution. However, the underlying problem was similar. Large quantities of pollutants, particularly under unfavorable weather conditions, could become trapped over cities and seriously endanger public health.

Air Pollution Regulation Before 1952

The 1950s did not mark the beginning of legal air pollution control. One of the most important early examples was the British Alkali Act of 1863. The Act targeted hydrochloric acid emissions from the alkali industry of the time. It required at least 95% of the gas generated during the process to be condensed. It also introduced inspections of industrial facilities.

This legislation is important because it shows that technically defined requirements for reducing specific industrial emissions already existed in the 19th century. Various cities later introduced local regulations against smoke and soot. These generally targeted specific emission sources, particular industrial processes, or visible smoke.

What changed in the 1950s was not simply the existence of regulations. It was the way the problem itself was understood.

The Great Smog of London Changes the Perception of the Problem

From 5 to 9 December 1952, London was covered by exceptionally dense smog.

The burning of large quantities of coal, combined with emissions from industry and transport and unfavorable weather conditions, caused smoke, soot, and sulfur dioxide to accumulate in the air over the city.

The consequences could no longer be regarded simply as an inconvenience caused by smoke. Around 4,000 additional deaths were recorded during and immediately after the Great Smog. Later estimates indicated an even greater overall health impact. The UK Parliament today directly links the Great Smog with the legislative measures that followed.

SEE ALSO: The Great Smog of London (1952): Lessons from the Past

The Great Smog was not London’s first smog episode. Its scale, however, demonstrated that air pollution could have catastrophic health consequences for an entire urban population.

London’s First Legislative Response

The first significant legislative step followed less than two years after the Great Smog. The City of London (Various Powers) Act 1954 received Royal Assent on 5 July 1954, formally becoming law. The part of the Act dealing with pollution reduction prohibited smoke emissions from buildings within the City of London.

The City of London thus became the first local authority in Great Britain to prohibit smoke emissions throughout its entire territory. This was not yet a national air quality control system, but the direction was clear.

The UK Clean Air Act Changes the Approach at National Level

Exactly two years later, on 5 July 1956, the Clean Air Act 1956 received Royal Assent and became law. The UK Parliament describes it as the first Clean Air Act to apply across the United Kingdom and places it directly in the regulatory sequence that followed the Great Smog and the 1954 London legislation.

Among other measures, the Act enabled the establishment of “smoke control areas.”

It regulated dark smoke emissions and introduced measures that encouraged a transition towards fuels and combustion methods with lower emissions. This represented a significant change. Legislation was no longer focused solely on one chemical industry or an individual chimney. Urban air pollution was beginning to be addressed systematically

Smog in New York

Only one year after the Great Smog of London, New York experienced a serious air pollution episode in November 1953. A multi-day temperature inversion and stagnant air allowed pollutants to accumulate. Sulfur dioxide and smoke concentrations reached unusually high levels. A subsequent analysis of health data showed a statistically significant increase in mortality during the period associated with the event.

However, the American path towards air pollution regulation should not be linked to a single event. The catastrophic Donora smog in Pennsylvania in 1948, Los Angeles’ long-standing problems with photochemical smog, the London disaster of 1952, and other pollution episodes gradually demonstrated that the problem exceeded the capacity of individual cities to address it.

SEE ALSO: Smog Threatens Health – Is There a Way Out?

Air Pollution Enters U.S. Federal Legislation

On 14 July 1955, the United States adopted the Air Pollution Control Act of 1955. The U.S. Environmental Protection Agency (EPA) identifies it as the first federal legislation in the United States to address air pollution.

Its scope, however, should not be equated with that of the British Clean Air Act. The U.S. legislation primarily provided funding for research, data collection, the development of pollution reduction methods, and technical assistance to state and local authorities. Primary responsibility for controlling air pollution remained with state and local governments.

The EPA identifies the Clean Air Act of 1963 as the first federal legislation to establish a federal air pollution control program.

How Tokyo Initially Regulated Soot and Smoke

At almost the same time, a similar process was taking place on a third continent. During Japan’s post-war reconstruction, industrial growth brought increasingly serious pollution problems. In 1949, Tokyo became the first city in Japan to adopt the Tokyo Metropolitan Factory Pollution Prevention Ordinance, a local regulation designed to control pollution from industrial facilities. According to Japan’s Ministry of the Environment, the ordinance did not yet include quantitative standards.

By the mid-1950s, air pollution had become particularly severe.

Japan’s Ministry of the Environment states that smog caused by soot and the combustion of heating fuels frequently covered urban areas. In response, Tokyo adopted the Tokyo Metropolitan Soot Prevention Ordinance in 1955.

The ordinance introduced smoke-density control based on the Ringelmann scale. Stricter criteria applied in residential areas than in other parts of the city.

What Is the Ringelmann Scale?

The Ringelmann scale is one of the oldest methods for visually assessing the density of black smoke. An observer compares the appearance of smoke with standardized shades of grey and black. The shades are represented on a numerical scale, with higher numbers indicating darker and optically denser smoke.

The scale did not measure particle concentrations in the modern sense. However, it made it possible to replace the subjective observation of “a lot of smoke” with a more standardized criterion that could be used for regulation and enforcement.

From a Local Ordinance to Japan’s First National Law

The Tokyo ordinance was not a national law. Japan did not introduce its first national legislation controlling smoke and soot emissions until 1962. Nevertheless, the 1955 ordinance is important because it illustrates another characteristic of the development of modern air pollution regulation: the transition from a general prohibition of excessive smoke to a criterion against which emissions could be assessed.

What Connects London, New York, and Tokyo?

British, American, and Japanese regulations did not have the same legal status, scope, or regulatory mechanisms. It would therefore be inaccurate to present them as three parallel national laws adopted in three countries on three continents.

What connects them is something else. Within a very short period, it became clear on three continents that urban air pollution was more than a local smoke problem and required an organized regulatory response. It was no longer simply a matter of visible smoke, unpleasant odors, or dirty building façades. It had become a public health issue.

At the same time, elements that would later become integral parts of modern air pollution regulation began to emerge: research into health effects; monitoring; definition of permitted emission levels; controlled zones; inspections; standardized assessment methods; increasing involvement of government authorities.

For this reason, the period from 1952 to 1956 did not mark the beginning of air pollution regulation, but it represented an important turning point in the development of its modern form.

From Visible Smoke to Measurable Air Quality

Since the 1950s, both the sources of air pollution and the way we measure it have changed.

Black smoke and soot are no longer the only indicators of the problems associated with polluted air.

Modern air pollution regulation addresses both emissions from pollution sources and permissible concentrations of pollutants in ambient air. Today, authorities monitor concentrations of PM₂.₅ and PM₁₀, nitrogen dioxide, sulfur dioxide, ozone, and other pollutants. Regulations define limit and target values, measurement methods, monitoring locations, reporting obligations, and measures to be taken when air quality deteriorates.

This development continues today.

SEE ALSO: New EU Air Quality Regulations

Protecting Health as a Driver of Air Pollution Regulation

The emergence of modern outdoor air quality regulation was closely linked to the recognition of the harmful effects of air pollution on human health. Major smog episodes demonstrated how serious the consequences of exposure to high concentrations of pollutants could be.

Today, increasing attention is also being given to indoor air quality, where people spend around 90% of their time on average. The COVID-19 pandemic further highlighted the importance of ventilation in indoor spaces. However, indoor air quality involves a much broader range of pollutants and sources.

Marquis Intelligence and Air Quality Today

Today, it is no longer enough to conclude that air is clean simply because we cannot see smoke or detect an unpleasant odor. Many pollutants that affect health are invisible to the human eye. At the same time, indoor air quality depends both on outdoor air and on pollution sources within the building itself.

For this reason, when addressing indoor air quality problems, Marquis Intelligence follows the principle that the problem must first be identified. It must then be measured and confirmed, after which an appropriate technical solution can be selected. Once the solution has been implemented, the achieved results should be verified.

Depending on the problem and the building, the solution may include: ventilation; filtration; air purification; system control; air quality monitoring.

Technologies have changed significantly since the days when smoke density was assessed by comparing it with shades of grey on the Ringelmann scale. The fundamental principle, however, remains very similar: what we want to control must first be identified and measured, and the results of the implemented solution must then be verified.

This Marquis Intelligence article is part of the professional series “News from the World of Ventilation and Clean Air Standards.”
Document No.: MI-NewLegislation-008.26 – Modern Air Pollution Regulation and Smog

The post Modern Air Pollution Regulation and Smog appeared first on Marquis Intelligence.

However, bipolar air ionization is a technology, not magic. Several prerequisites must be met to achieve effective air treatment.

Prerequisites for Effective Bipolar Air Ionization in a Central Ventilation System

Bipolar air ionization can provide many benefits as part of a central ventilation system, provided that:

• the bipolar ionization system is properly designed and coordinated with the central ventilation system;
• the bipolar ionization equipment, as well as the other components of the central ventilation system, is functional and of good quality;
• the systems are properly configured, operate together as intended, and receive appropriate maintenance.

When these prerequisites are met, bipolar air ionization becomes an integral part of the system for controlled air treatment and distribution throughout the home.

Benefits of Bipolar Air Ionization in a Central Home Ventilation System

What are the main benefits of bipolar air ionization when it forms part of a properly designed central ventilation system?

1. Provides Additional Treatment of Fresh Air After Filtration

Outdoor air today is generally not clean. According to the World Health Organization, 99% of the world’s population lives in areas where air pollution levels exceed WHO guideline limits.
It is therefore particularly important to clean outdoor air in a central ventilation system before introducing it into the home. As a rule, the air first passes through filters that remove particulate pollutants.

Bipolar air ionization provides an additional level of air treatment after filtration. Positive and negative ions are introduced into the already filtered airflow before the system distributes it throughout the home.
As a result, the rooms receive not only filtered outdoor air but also air that has undergone additional bipolar ionization treatment.

2. Acts on Both Outdoor Pollution and Pollution Generated Inside the Home

This is one of the particularly important benefits of bipolar air ionization in a central ventilation system.

Outdoor air is often polluted, but pollution sources also exist inside our homes. According to the U.S. Environmental Protection Agency (EPA), concentrations of some pollutants indoors are often two to five times higher than typical outdoor concentrations.

At the same time, we spend about 90% of our time indoors. The Healthy Buildings Program at the Harvard T.H. Chan School of Public Health states that we spend around 65% of our lives in our homes.

This makes one feature of bipolar air ionization in a central ventilation system particularly important: its effect is not limited to the outdoor air passing through the system.

Cooking, cleaning, people, pets, furniture, finishing materials, and products we use every day can generate particles, odors, volatile organic compounds, and microbiological contaminants.
The system distributes positive and negative ions throughout the rooms together with the treated air. They can therefore also act on pollutants generated inside the home.

3. Reduces the Number of the Smallest Airborne Particles

One important application of bipolar air ionization is the reduction of very small particles.

Ions charge airborne particles and can promote their agglomeration. This creates larger particle structures that can be removed from the air more easily.

This effect is particularly important for ultra-fine particles, which have a diameter of up to 0.1 µm. Because of their small size, these particles can penetrate deep into the lungs. Some may also enter the bloodstream. Exposure to ultra-fine particles is associated with an increased risk of respiratory and cardiovascular diseases.

SEE ALSO: 11 Questions and Answers: How Do PM2.5 Particles Affect Health?

4. Can Improve Particle Filtration Efficiency

Bipolar air ionization and filtration are not two completely separate processes. In a properly designed system, they can complement each other.

Charging particles and promoting their agglomeration changes the way they behave in the air. When these ionized particles subsequently pass through a filter, the filter may capture them more effectively.

The effect depends on the system configuration, the position of the ionizer, and air circulation. Any potential improvement in filtration efficiency must therefore be evaluated as part of the complete system, rather than as an isolated characteristic of the ionizer.

5. Helps Reduce Unpleasant Odors

Unpleasant odors in the home often result from emissions of various gaseous compounds. Cooking, cleaning, and other everyday activities can generate these compounds.

Bipolar air ionization can act on certain compounds responsible for unpleasant odors, and help reduce them.

Because the system distributes the ions together with the air, their effect is not limited to the location where the ionizer is installed.

6. Can Reduce Concentrations of Volatile Organic Compounds – VOCs

Volatile organic compounds (VOCs) can originate from emissions from furniture, building and finishing materials, cleaning products, cosmetics, and other products used indoors.

Bipolar air ionization can help reduce the concentrations of certain VOCs in the air.

The effect depends on the type of compound, the technology used, the ion concentration, the contact time, and indoor conditions. For this reason, test results for a specific device should always be considered in the context of the technology and the system in which it is used.

7. Helps Reduce Airborne Allergens

Airborne allergens can enter from outdoors, but many sources also exist inside the home. Pollen, mold spores, and allergens associated with dust mites and pets are just some examples.

Many allergens travel through the air as particles of different sizes. By charging these particles and promoting their agglomeration with other particles, bipolar air ionization can help remove them from the air more effectively.

In a central ventilation system, there is an additional benefit: the system treats both the air entering from outdoors and the air containing allergens released or resuspended inside the home.

8. Acts on Microbiological Contaminants

Bipolar air ionization can act on certain microorganisms present in the air and on surfaces that come into contact with treated air. The effect depends on the type of microorganism, the technology used, the ion concentration, and exposure time.

It is therefore important to use proven equipment with documented test results and to apply it correctly within the specific system.

9. Helps Maintain the Microbiological Hygiene of the Air Distribution System

This is another specific benefit of bipolar air ionization in a central ventilation system.

The ions travel with the air through the distribution network before reaching the rooms. The treated air therefore also comes into contact with the internal surfaces of ventilation ducts and other air distribution components.

In this way, bipolar air ionization can help maintain the microbiological hygiene of the air distribution system.

Does Bipolar Air Ionization Replace Filtration?

No. Bipolar air ionization and filtration perform different functions in air treatment.

A filter captures particles from the air that pass through it. Bipolar air ionization provides additional air treatment. The ions then continue to travel with the air through the distribution network and into the rooms.

This is precisely why bipolar air ionization can also act on pollutants generated after filtration, within the air distribution system, and inside the home.

SEE ALSO: Heat Recovery Ventilation: 8 Benefits for Your Home

Is Every Bipolar Air Ionization Technology the Same?

No. Technologies differ in the way they generate ions, device design, the quantity and ratio of positive and negative ions produced, their effective range, and potential by-products. As a result, individual devices can achieve different effects in real systems.

The experience and expertise of the equipment manufacturer are therefore important. So are the knowledge and experience of the designers and installers who apply the technology. Regular maintenance of both the system and the equipment is essential for efficient and long-lasting operation.

SEE ALSO: FAQ – Marquis Intelligence: Bipolar Air Ionization

What Do Measurements Show in a Home with Central Ventilation and Bipolar Air Ionization?

The declared performance of individual devices provides a starting point. However, what matters more to the user is how the complete system performs after installation.

In an apartment of approximately 200 m² in Belgrade, Marquis Intelligence designed and implemented a central ventilation system with heat recovery, additional filtration, bipolar air ionization, and humidification.

The ionizer was installed immediately upstream of the air distribution manifold. This allows the system to distribute ionized air through the duct network and into the rooms.

After approximately 24 hours of continuous system operation with the windows closed, an independent scientific institute carried out instrumental air quality measurements. The measurements showed fewer than 50 particles/cm³ in the 0.3 to 10 µm range. Ozone, SO₂, and NO₂ were not detected during the measurements.

SEE ALSO: Mini Case Study: Verifying the Performance of a Central Ventilation System in an Apartment

This example shows why we should not assess performance based only on the characteristics of an individual device. In a real system, ventilation, filtration, bipolar air ionization, air distribution, and proper system configuration work together.

Experience Matters When Designing an Effective Solution

Marquis Intelligence has used bipolar air ionization as part of indoor air quality improvement systems for more than two decades. Their experience covers different bipolar ionization technologies. In some projects, they combine both main technologies within the same building. This approach can also be used in home ventilation systems.

Marquis Intelligence also has extensive experience with these systems in commercial, public, hospitality, and healthcare buildings.

For this reason, selecting a solution should not begin with the question: Which bipolar ionizer should we install? The first step is to define what we want to achieve in the specific space and identify its limitations.

Only then can we select the appropriate technology, device, installation location, and operating method.

When designed in this way, bipolar air ionization in a central ventilation system is more than an additional device. It becomes part of an engineered indoor air quality solution for the home or another type of building.

SEE ALSO: Residential Ventilation by Marquis Intelligence

This article is part of the Marquis Intelligence professional series “Home Ventilation.”
Document No. and Title: MI-HV-009.26 – 9 Benefits of Bipolar Air Ionization in a Central Home Ventilation System

The post 9 Benefits of Bipolar Air Ionization in a Central Home Ventilation System appeared first on Marquis Intelligence.

A high faucet, suspended ceiling, or the position of an existing duct can determine the final solution. A detail overlooked on a drawing can become an everyday operational problem in the kitchen.

What Needs to Be Extracted from the Dishwashing Area?

When we think of commercial kitchen ventilation, we usually think of extraction above cookers, grills, and fryers. However, the dishwashing area also generates heat, moisture, and airborne pollutants.

The hood and its exhaust system remove warm, humid air, odors, and fine droplets dispersed in the air-liquid aerosols. Depending on the chemicals used and the operating process, these droplets may also contain components of detergents, rinse aids, or disinfectants.

The aim is to limit the spread of these emissions into the working area. This includes the visible cloud of fine droplets released when the dishwasher opens, commonly referred to as “steam”.

If the system does not remove enough moisture, water vapor can condense on cooler surfaces such as ceilings, walls, and equipment. Prolonged surface moisture can promote mold growth and make it more difficult to maintain good hygiene.

Does Every Dishwasher Need an Exhaust Hood?

No. Some professional dishwashers have integrated steam condensation or heat recovery systems. For certain models, the manufacturer allows operation without a separate external hood under clearly defined conditions.

The decision therefore depends on the specific dishwasher, its technical documentation, and the requirements of the building. The ventilation and air-conditioning calculations must still account for any remaining heat and moisture loads.

What Type of Hood Is Used Above a Dishwasher?

The ASHRAE Handbook – HVAC Applications, in its chapter “Kitchen Ventilation”, distinguishes between two types of hoods:

• Type I – for emissions containing grease and smoke;
• Type II – for removing heat and moisture without these emissions.

Under this classification, an exhaust hood above a professional dishwasher is a Type II hood when its purpose is to remove heat and moisture without capturing grease and smoke generated by cooking processes.

This classification is useful when working on international projects and reviewing foreign technical documentation. For each individual project, however, designers must also check the applicable national regulations and standards.

Is Hood Selection Based Only on the Dishwasher Dimensions?

The width and depth of the closed dishwasher are not enough to determine the correct hood.

The way the dishwasher opens also matters. So do the arrangement of surrounding equipment and the workflow throughout the dishwashing area.

The hood dimensions and position must allow it to capture emissions effectively. At the same time, staff must be able to work without obstruction and have adequate access for maintenance.

Why Does the Way the Dishwasher Opens Matter?

For professional hood-type dishwashers, designers must check the total height of the unit when fully open. This includes the lifting mechanism and handles. The exhaust hood must be positioned high enough to allow the dishwasher to open completely.

For front-loading dishwashers, the position of the open door and the area required to pull out the dish rack must be considered. In both cases, the exhaust hood should cover the area where steam is released.

The installation height and hood overhangs depend on the dishwasher’s technical parameters and operating method, the manufacturer’s documentation, and local airflow conditions.

High Faucet and Pre-Rinse Spray

A pre-rinse sink is often installed next to the dishwasher. It typically has a high faucet, flexible hose, and pre-rinse spray. This assembly may be higher than the closed dishwasher and can therefore determine the hood installation height.

The height of the faucet is not the only consideration. Designers must also account for the movement of the hose and the space required for handling it. If the hood also covers the pre-rinse area, its footprint should extend over the relevant working area above the sink.

Raising the hood to provide enough space for the faucet increases the distance between the hood and the source of emissions. Designers must therefore reassess steam capture and the required exhaust airflow.

Metal Filters or Droplet Eliminators?

Metal elements installed in a hood above a dishwashing area may look like grease filters. However, their appearance alone does not reliably indicate their function.

Droplet eliminators, or droplet separators, remove water droplets from the exhaust air. In designs with profiled blades, the air changes direction several times. Inertia causes the droplets to separate from the airflow and collect on the metal surfaces. They then merge and drain towards the collection point.

Grease filters, on the other hand, are designed to separate grease aerosols. The correct element must therefore be selected according to its intended function, airflow rate, and declared separation performance.

Mechanical droplet separation does not remove gaseous substances that cause odors. Nor does it remove water vapor itself. Water vapor may remain in the air and later condense on cooler surfaces within the system.

Where Does the Condensate Go?

In some hood designs, the internal surfaces and baffles promote water vapor condensation and collect the resulting water.

It is important to distinguish between condensation and droplet separation.

Condensation is the process by which water vapor changes into liquid water. Droplet eliminators mechanically separate droplets that are already present in the air.

The hood’s internal surfaces should direct water towards a collection channel or tray with suitable drainage or emptying provisions. Condensate must not drip uncontrollably onto clean dishes, work surfaces, or employees.

Condensate can also drain from the ventilation duct through the hood’s exhaust connection. Depending on the system design, an additional baffle may be required to collect this condensate and direct it towards the drain.

The duct system design should also consider the risk of condensation, the need for insulation, appropriate duct slopes, and suitable water collection points.

Are All Hoods Made from the Same “Stainless Steel”?

The term “stainless steel” alone is not a sufficient material specification for a kitchen hood.

The choice between AISI 304 and AISI 316 stainless steel depends on several factors: water composition; chemicals used; temperature; exposure to condensate; maintenance procedures.

AISI 304 may be suitable for the expected operating conditions. A more corrosive environment, however, may justify the use of AISI 316. The term “acid-resistant steel” does not mean that the material is resistant to every chemical or every concentration.

Surface finish and joint quality are equally important. The design should also avoid areas where water and contaminants can accumulate.

Position and Dimensions of the Exhaust Connection

The position of the exhaust connection must match the hood geometry, exhaust airflow distribution, and duct route. Larger hoods may require more than one exhaust connection. In that case, the airflow must be properly balanced.

The required airflow rate and selected air velocity determine the cross-sectional area of the connection. Designers must also check pressure drop and noise levels.Gradual transitions and elbows with larger bend radii reduce local airflow resistance.

Lighting and Maintenance Should Be Planned in Advance

The hood may block ceiling lighting. Good visibility must therefore be provided in the dishwashing and dish inspection areas. Built-in lights and electrical connections must have an appropriate IP protection rating. The required rating depends on exposure to moisture and splashing, as well as the cleaning method.

Droplet eliminators and other washable components should be easy to remove and reinstall. The inside of the hood, collection channel, condensate drain, and lights must remain accessible for cleaning and maintenance.

Is the Hood Alone Enough to Remove Steam and Vapors?

No. Removing heat, vapors, and odors requires a complete and functional system: an exhaust hood;an appropriate exhaust connection; ductwork; a fan; a properly selected discharge location.

A hood without an integrated fan can be connected to a separate exhaust system. The fan may be installed in the duct or elsewhere in the system. The absence of a fan inside the hood does not mean that the exhaust system operates without one.

The need for additional exhaust air purification depends on the composition of the exhaust air, the discharge location, and its impact on the surrounding environment.

SEE ALSO: Commercial Kitchen Exhaust Ventilation: From Fire Risk to Safe Operation
SEE ALSO: Mini Case Study: Commercial Kitchen Ventilation Under Space Constraints in the City Centre

A More Powerful Fan Is Not Always the Solution

The required airflow rate and the total system resistance determine the correct fan selection. Supply and exhaust airflow must be balanced to maintain the designed pressure differences between zones.

Increasing the airflow does not necessarily improve steam capture. If the hood position or dimensions are inadequate, higher airflow alone will not solve the problem. The same applies if the supply air pushes steam away from the hood’s capture zone.

System performance should be verified by measuring airflow and observing steam capture.

This is particularly important when opening a hot dishwasher while the surrounding equipment is operating.

Applicable Standards

The EN 16282 series provides a relevant framework for commercial kitchen ventilation. Part 1 covers general requirements and airflow calculations. Part 2 covers the design and requirements for kitchen ventilation hoods, including safety and hygiene characteristics.

Designers should always check the current editions of the standards and the requirements applicable to the specific project.

• Institute for Standardization of Serbia – SRPS EN 16282-1:2017 and its revision project
• Institute for Standardization of Serbia – SRPS EN 16282-2:2017

A Practical Example from Marquis Intelligence

For the canteen of an IT company in the Green Heart business complex in New Belgrade, Marquis Intelligence designed, supplied, and installed an exhaust hood above a new, larger dishwasher.

Replacing the existing dishwasher required a new exhaust ventilation calculation and a new hood design. The assessment showed that the existing exhaust duct and fan could meet the requirements of the new dishwasher. However, the existing hood had to be replaced.

The suspended ceiling limited the available installation space. At the same time, the offset centreline of the new dishwasher made it more difficult to connect the hood to the existing exhaust duct. During installation, the team used hydraulic cylinders to lift and level the hood.

Protecting the interior finishes and existing equipment from dirt and damage during the work presented an additional challenge.

SEE ALSO: FAQ – Exhaust and Purification of Waste Air from Kitchen Hoods

Marquis Intelligence designs, installs, and maintains commercial kitchen ventilation systems, including exhaust ventilation and exhaust air purification.

The company also designs and installs kitchen hoods adapted to the equipment, work processes, and spatial constraints of each project. This includes exhaust hoods above professional dishwashers.

Investors and operators planning a new commercial kitchen, renovating an existing one, or replacing a dishwasher can contact the Marquis Intelligence technical team. Our team can design and implement a solution tailored to the equipment and the specific conditions of the space.

This article is part of the Marquis Intelligence professional series “Commercial Kitchen Ventilation and Exhaust Air Purification”. The series addresses technical challenges in professional kitchen ventilation, with a particular focus on exhaust ventilation and exhaust air treatment under real operating conditions.

Document: MI-KV-002.26 – Exhaust Hood Above a Dishwasher in a Commercial Kitchen

The post Exhaust Hood Above a Dishwasher in a Commercial Kitchen appeared first on Marquis Intelligence.

The number 100 is often associated with completeness, achievement, and a milestone that is easy to remember. However, the true value of this anniversary lies in the knowledge preserved through these published articles.

Why Is Air the Only Topic of the Marquis Intelligence Blog?

Because air is the company’s core field of expertise.

Marquis Intelligence designs and implements ventilation and air purification systems. We develop solutions for commercial kitchen ventilation and exhaust air purification. We integrate technologies that improve indoor air quality and maintain the systems we install.

That is why air is not an abstract subject on this Blog. It is something we design for, distribute, purify, extract, control, and manage through regular maintenance.

This technical foundation has also led to articles about health, the environment, history, standards, and the broader social importance of clean air. These topics explain why air quality and the proper operation of technical systems matter.

Do the Articles Need to Be Engaging and Easy to Understand?

Of course. Technical accuracy is not enough if only a narrow group of specialists can understand the content.

Our articles combine technical explanations with real-world stories, historical events, readers’ questions, and everyday situations. Case studies present the problem, site conditions, engineering approach, and implemented solution. Articles on scientific topics present research findings in language that remains precise while still being easy to read.

Making technical content understandable does not mean simplifying it to the point of inaccuracy. It means allowing designers, investors, facility managers, and building occupants to understand why a particular technical decision matters.

Everyone breathes air. Everyone should therefore understand how its quality can affect health, comfort, and quality of life.

Clean air is a right for everyone.

How Are Marquis Intelligence Blog Articles Created?

Marquis Intelligence Blog articles serve as records of our knowledge about air. We create them by combining different sources of knowledge and practical experience.

Some content comes from scientific papers, professional publications, international standards, regulations, and educational webinars. Other content comes directly from our work: engineering design, technical implementation, system commissioning, and equipment maintenance.

Depending on the topic, we also use measurement results, project documentation, service reports, and the experiences of building occupants.

Each article offers new knowledge, a different perspective, or practical experience. In this way, it helps readers understand the subject more clearly.

A great deal of engineering knowledge would otherwise remain hidden in technical calculations, quotations, project files, and system performance reports. The Blog allows us to preserve that experience and share it beyond a single project, building, or group of people involved in its implementation.

SEE ALSO: Grande Case Study: Electrostatic Precipitator at Dijamant, Zrenjanin

Lessons from 100 Blog Posts

One hundred articles do not necessarily mean one hundred completely separate conclusions. Air is the golden thread that connects them all. However, several lessons recur across different topics, buildings, and periods:

• Air cannot be considered separately from the space.
  Its quality depends on the purpose of the building, the number of occupants, pollution sources, the type of ventilation, and how the space is used.
• Ventilation and air purification are not the same.
  Ventilation provides controlled air exchange, while air purification targets specific pollutants. Many buildings need both.
• No single technology is best for every problem.
  The value of a technical solution depends on selecting the right technology, designing and positioning it correctly, installing it properly, and verifying the results.
• Responsibility for a system does not end with commissioning.
  Maintenance determines whether the system will continue to deliver its designed performance after years of operation.
• Air quality connects different disciplines.
  Engineering intersects with medicine, energy, architecture, environmental science, safety, and the way people use buildings.
• Knowledge becomes more valuable when we share it.
  Experience from one project can help another investor, designer, or user identify a problem earlier and make a better decision.

These recurring lessons have also helped shape the Marquis Intelligence air knowledge repository. After all, repetition is the mother of learning.

Who Is the Content Intended For?

Different topics naturally appeal to different groups of readers.

Articles about health and history are easy to relate to everyday experience and therefore appeal to a broad audience. Technical analyses and articles about standards and regulations are more directly relevant to designers, engineers, investors, and facility managers.

Case studies often connect these groups.

An example from a hospital may be relevant to ventilation designers as well as healthcare professionals.

An article about indoor air quality in a space where smoking is permitted may interest engineers, hospitality business owners, employees, and guests.

A story about commercial kitchen ventilation raises several issues at once: fire safety, odors, energy losses, working conditions, and the building’s impact on its surroundings.

The audience of the Marquis Intelligence Blog therefore cannot be limited to a single profession or field of interest. It connects professionals who work with air with the people who breathe it every day.

Some Marquis Intelligence articles also leave a strong personal impression on readers. After we published an article about the Great Smog of London, we heard from a man who had personally experienced the event. More recently, our article about Gordana Blagić, Technical Director and co-owner of Marquis Intelligence, inspired one of our LinkedIn followers to write a poem for her.

These reactions show that topics related to air can sometimes go beyond their technical context and become part of a personal memory, experience, or emotion.

SEE ALSO: Twenty Years of Gordana Blagić at Marquis Commerce

When a Blog Becomes a Knowledge Platform

After 100 published articles, the Marquis Intelligence Blog has long since grown beyond the boundaries of a conventional company blog.

Unlike a product catalogue, it does not simply describe what a particular piece of equipment can do. It explains when a technology makes sense, what its limitations are, and how its performance can be verified in a real building.

Unlike a purely theoretical platform, the Blog draws directly on practical experience from engineering design, project implementation, system commissioning, and maintenance.

The articles are written by team members who take part in these processes. Their different perspectives allow us to explore air from engineering, health, historical, regulatory, environmental, and business perspectives.

In this way, the Blog has become an air knowledge platform. It is understandable to people and organized clearly enough for modern search systems to recognize and interpret its content.

SEE ALSO: FAQ – Marquis Intelligence Blog

How Is the Marquis Intelligence Air Knowledge Repository Organized?

According to company records, the published articles are organized into eight specialist series, while 17 articles currently stand alone. Since the archive contains exactly 100 blog posts, the number of articles in each group also represents its percentage of the total content.

• Marquis Intelligence – Business and Development: 24 articles
• Air Pollution and Health: 14 articles
• Learn More About Air Through History and People: 13 articles
• Mini Case Studies: 9 articles
• Home Ventilation: 8 articles
• News from the World of Ventilation and Clean Air Standards: 7 articles
• Air Quality, Environment and Sustainability: 7 articles
• Commercial Kitchen Ventilation and Exhaust Air Purification: 1 article
• Other articles not currently included in a series: 17 articles

This classification shows the primary series for each article, but it does not create rigid boundaries between topics. The articles overlap and connect through internal links, forming a unified system of knowledge.

How Do the Different Series Interconnect?

An article from the business series may also document technology development, project implementation, and system maintenance. A historical article may connect medicine, ventilation, and infection control.

A health-related topic may raise questions about air quality in a home, school, hospital, or workplace.

The Commercial Kitchen Ventilation and Exhaust Air Purification series has only recently been formally introduced. However, the same field of expertise already appears in case studies, project stories, and articles about exhaust systems.

Standalone articles are no less important. Some address specific topics, while others may form the starting point for future content clusters. A new series only makes sense when there are enough related articles to develop a particular subject systematically.

When Knowledge Becomes Recognizable

Some articles on the Marquis Intelligence Blog rank among prominent Google search results, while others also appear in AI Overviews.

This visibility did not come from a single article or a single keyword. We built it through consistency, technical depth, authentic experience, and strong connections between related content.

For the search query “Blog as an air knowledge repository,” Google AI Overview associated the phrase with the Marquis Intelligence Blog. It particularly recognized the Blog’s educational, health, environmental, and historical dimensions.

These are important parts of the content, but engineering remains its foundation.

Google Search Console data for generative AI features provides further evidence of this visibility. During the 28 days preceding the preparation of this article, our blog post “The Great Smog of London 1952” appeared more than 5,000 times in results associated with generative artificial intelligence.

SEE ALSO: The Great Smog of London (1952): Lessons from the Past

The design and maintenance of ventilation systems, air purification, commercial kitchen ventilation, and exhaust air treatment form the technical core from which the other topics have developed.

Visibility is therefore not a goal in itself. It is a result of recording, organizing, and making knowledge available in a clear and accessible way.

The phrase “air knowledge repository” was not chosen simply because it makes an appealing title. It describes content that connects different disciplines while keeping each of them clearly linked to air.

The 100th Blog Post as the Beginning of a New Cycle

The 100th blog post is not the end. It marks the point from which the Marquis Intelligence air knowledge repository will continue to grow.

The next cycle will bring new technical questions, case studies, and thematic areas. Another challenge will be to improve the platform’s architecture and organization. The goal is to make the content easier to search, more clearly interconnected, and simpler to use.

However, the fundamental principle remains the same: Knowledge should be preserved, connected, and made understandable.

Air is invisible.

Knowledge about it should not be.

This 100th blog post was published exactly on the fourth anniversary of the Marquis Intelligence Blog.

This article is part of a series of publications presenting the work and business results of Marquis Intelligence.
Document No.: MI-PROM-26.023 – The Blog as an Air Knowledge Repository

The post The Blog as an Air Knowledge Repository appeared first on Marquis Intelligence.

Large population studies show a link between long-term exposure to polluted air and a higher incidence of dementia. This does not mean that every exposed person will develop dementia. However, the increased risk is clear.

Dementia and Alzheimer’s Disease

Dementia is a general term for a group of symptoms. These include declining memory, thinking, reasoning, and the ability to perform everyday activities.
A person may have changes associated with more than one type of dementia.

Alzheimer’s disease is the most common cause of dementia. It accounts for approximately 60–70% of all dementia cases.

Vascular dementia results from blood vessel damage and impaired blood supply to the brain.

What Do the Latest Studies Show About Air Pollution and Dementia?

A systematic review and meta-analysis published in The Lancet Planetary Health in 2025 included 51 studies and data from more than 29 million people.

The studies examined whether long-term exposure to air pollution increases the risk of dementia. They defined long-term exposure as a period of at least one year.

Which Air Pollutants May Increase the Risk of Dementia?

Researchers found a statistically significant association between dementia and three indicators of air pollution:

• PM2.5: Every additional 5 µg/m³ in average long-term exposure was associated with an approximately 8% higher relative risk of dementia.
• Nitrogen dioxide (NO₂): Every additional 10 µg/m³ was associated with an approximately 3% higher relative risk.
• Soot, or black carbon: Every additional 1 µg/m³ was associated with an approximately 13% higher relative risk.

These percentages refer to changes in relative risk, not absolute risk.

A person’s actual absolute risk depends on age, genetics, cardiovascular health, lifestyle, and other factors.

Exposure to PM2.5

PM2.5 refers to suspended particulate matter with an aerodynamic diameter of up to 2.5 micrometres. This fraction includes particles with different actual sizes, shapes, densities, chemical compositions, and origins.

A US cohort study published in JAMA Internal Medicine in 2023 followed 27,857 people over the age of 50 for an average of 10.2 years. Researchers found the most consistent association with new cases of dementia for PM2.5 from agriculture and wildfires. The study examined long-term exposure. It does not show that a single wildfire increases the risk of dementia.

SEE ALSO: 11 Questions and Answers: How Do PM2.5 Particles Affect Health?

PM2.5 and the Risk of Alzheimer’s Disease

A large US cohort study published in PLOS Medicine in 2026 included 27.8 million Medicare beneficiaries aged 65 and older. An increase of 3.8 µg/m³ in five-year average PM2.5 exposure was associated with an approximately 8.5% higher relative risk of a new Alzheimer’s disease diagnosis. The association was slightly stronger in people who had previously suffered a stroke.

How Can Air Pollution Increase the Risk of Dementia?

Scientists are still studying the mechanisms that could explain why air pollution increases the risk of dementia. Evidence points to several interconnected processes.

Systemic Inflammation

Particles that penetrate deep into the lungs can trigger inflammatory responses.Inflammatory signals can then affect blood vessels and the brain.

Oxidative Stress

Air pollutants can impair the body’s ability to neutralize reactive molecules. This can damage cell membranes, proteins, and DNA.

Blood Vessel Damage

Air pollution is associated with hypertension, atherosclerosis, heart disease, and stroke. These conditions can contribute to vascular brain damage and dementia.

Possible Direct Pathways to the Brain

Ultrafine particles and some components of air pollution can enter the bloodstream.

Air pollution most likely affects the body through several pathways at the same time. It can act through the lungs, blood vessels, and immune system. Under certain conditions, it may also directly affect nervous tissue.

SEE ALSO: PM2.5 Particles Affect the Heart and Cardiovascular System
SEE ALSO: Air Pollution Affects Our Brain

Can Cleaner Air Help Reduce the Risk of Dementia?

In July 2026, the World Health Organization (WHO) published the second edition of its guidelines for reducing the risk of cognitive decline and dementia. For the first time, WHO included specific recommendations for reducing exposure to air pollution.

One recommendation addresses household air pollution. The other addresses ambient air pollution, particularly PM2.5.

A US study of 2,239 women aged 74 to 92 also points to the potential benefits of cleaner air. None of the participants had dementia at the beginning of the study. Over the preceding decade, a reduction in PM2.5 of 1.78 µg/m³ or in nitrogen dioxide of 3.91 ppb was associated with an approximately 20% lower relative risk of dementia. The median follow-up period was 6.1 years.

The study was observational. It therefore does not prove that improved air quality alone caused the lower risk. However, it shows that cleaner air may also be important later in life.

We Can Influence Our Own Exposure

Individuals have limited influence over outdoor air quality. However, we can reduce our exposure to some extent. We can monitor air quality and avoid spending time outdoors during periods of high pollution. But also, we can avoid strenuous outdoor exercise during these periods and choose routes away from busy roads.

We have much more control over the air quality in our own homes. Our decisions largely determine the quality of the air we provide for ourselves and other members of our household.

According to the Harvard University Healthy Buildings Program, we spend an average of 65% of our lives at home. Indoor air quality is therefore an important part of our total exposure. It is also something we can directly influence.

General Recommendations

The first step is to reduce the air pollution generated indoors.

Recommendations include:

• avoid cooking over an open flame whenever possible;
• limit the use of candles, incense, and other combustion sources;
• effectively extract pollutants generated during cooking;
• choose materials and products with lower pollutant emissions;
• do not smoke indoors;
• maintain good household hygiene;
• provide adequate ventilation;
• monitor PM2.5 and carbon dioxide (CO₂) concentrations;
• regularly maintain ventilation systems and replace filters.

A Local Air Purifier Is Not a Substitute for Ventilation

Local air purifiers can effectively reduce PM2.5 concentrations in a room if they have an appropriate filter and sufficient capacity. However, they do not supply fresh air. They therefore cannot reduce the carbon dioxide produced by occupants.

Air purifiers with standard particulate filters also do not remove gaseous pollutants such as nitrogen oxides (NOx) and sulfur oxides (SOx). Reducing these pollutants requires appropriate molecular filtration.

NOx and SOx can enter a building with outdoor air. Indoor combustion can also generate these pollutants.

Central Ventilation Systems Offer More Options

Compared with decentralized solutions, a central ventilation system usually offers more options for treating the air supplied to a building. More available space and higher available fan pressure allow the use of several filtration stages. These may include prefilters, fine particle filters, and molecular filters for specific gaseous pollutants.

The system treats the air before distributing it to individual rooms. At the same time, it can provide a controlled supply of fresh air, extract stale air, recover heat, and distribute air more evenly throughout the home.

Decentralized ventilation systems can be a good solution when there is no space for ductwork. However, limited space inside the unit and a smaller available filter area usually restrict the possibilities for multi-stage air treatment.

SEE ALSO: Mini Case Study: Verifying the Performance of a Central Ventilation System in an Apartment

Is a Central Ventilation System a Guaranteed Solution?

A central ventilation system does not provide these benefits automatically. Its performance depends on correct calculations, proper filter selection, available fan pressure, system airtightness, airflow balancing, and regular maintenance.

For this reason, the selection process should not start with the question: Which unit should I buy? Marquis Intelligence first analyzes the sources of pollution, outdoor air quality, how occupants use the space, and the existing technical conditions. Based on this analysis, we determine the required ventilation, particulate and molecular filtration, additional air treatment technologies, control strategy, and maintenance requirements.

The goal is not simply to purify air that is already inside the room. We need to provide enough fresh air and properly treat the air that we introduce into the home in a controlled way.

Clean Air Is a Good Foundation for a Healthier Life

Many factors contribute to dementia. Evidence shows that air pollution increases the risk of dementia. We cannot change our age or genetics. However, we can reduce our exposure to polluted air.

This does not mean that an air purifier, filter, or ventilation system can prevent dementia. Their role is to reduce our exposure to air pollutants and provide healthier conditions in the place where we spend most of our lives – our home.

References

1. World Health Organization. Dementia. Updated 3 July 2026. WHO.
2. Best Rogowski CB, Bredell C, Shi Y, et al. Long-term air pollution exposure and incident dementia: a systematic review and meta-analysis. The Lancet Planetary Health. 2025. DOI: 10.1016/S2542-5196(25)00118-4
3. Zhang B, Weuve J, Langa KM, et al. Comparison of Particulate Air Pollution From Different Emission Sources and Incident Dementia in the US. JAMA Internal Medicine. 2023;183(10):1080–1089. DOI: 10.1001/jamainternmed.2023.3300
4. Deng Y, Liu Y, Hao H, et al. The role of comorbidities in the associations between air pollution and Alzheimer’s disease: A national cohort study in the American Medicare population. PLOS Medicine. 2026;23(2):e1004912. DOI:10.1371/journal.pmed.1004912
5. World Health Organization. Risk reduction of cognitive decline and dementia: WHO guidelines, second edition. 2026. WHO
6. Wang X, Younan D, Millstein J, et al. Association of improved air quality with lower dementia risk in older women. Proceedings of the National Academy of Sciences. 2022;119(2):e2107833119. DOI: 10.1073/pnas.2107833119

This article is part of the “Air Pollution and Health” series, in which Marquis Intelligence, as a socially responsible company, highlights the adverse effects of air pollution on human health.

Document: MC-AP&H-015.26 – Does Air Pollution Increase the Risk of Dementia?

The post Does Air Pollution Increase the Risk of Dementia? appeared first on Marquis Intelligence.

The verification process begins with a review of the engineering calculations and system design. Next, the team inspects the installation and checks whether all installed components comply with the design documentation.

The team then commissions the system and checks the functionality of all components. After that, airflow rates are balanced and the achieved airflow is measured. Finally, key indoor air quality parameters are verified.

To explain this process more clearly, the following sections describe the installed system, its design constraints, and the specific engineering challenges.

In an approximately 200 m² apartment in Belgrade, Marquis Intelligence designed and implemented a central ventilation system with a high-efficiency heat recovery unit.

To meet the client’s demanding requirements, Marquis Intelligence added a dedicated filtration chamber, a bipolar ionization system, and a steam humidifier.

Architecture as a Limiting Factor in Ventilation System Design

This project shows how strongly building architecture can influence the selection, configuration, and long-term performance of a ventilation system.

Building Location and Apartment Position

The apartment is located in an existing multi-storey building with a glass façade. The building has an Energy Performance Class A rating.

From the earliest design stages, Marquis Intelligence had to adapt the ventilation system to the existing architecture, available installation space, and other building services.

A Glass Façade as a Constraint on Ventilation System Selection

At the beginning of the project, Marquis Intelligence evaluated both centralized and decentralized ventilation concepts.

The glass façade ruled out individual façade penetrations for the outdoor air intake and exhaust required by decentralized ventilation units. For that reason, the team rejected decentralized ventilation as technically infeasible.

Marquis Intelligence therefore selected a central ventilation system with a radial duct distribution network serving each room independently.

Even then, the façade could not accommodate either the outdoor air intake or the exhaust air discharge. The team therefore designed separate intake and exhaust routes.

Fresh outdoor air enters from the roof terrace. The team had to consider the location of other rooftop installations, especially existing kitchen and sanitary exhaust systems connected to the building’s vertical shafts.

The design also had to account for the shaft carrying fresh air from the roof to the apartment several floors below.

These constraints made both the engineering design and the subsequent performance verification particularly demanding.

SEE ALSO: Decentralized Home Ventilation Systems: Advantages and Limitations

Interior Design as a Design and Installation Constraint

The apartment’s interior design significantly influenced how the central ventilation system could be installed.

The first major decision concerned the location of the heat recovery unit. The team then determined the position of the humidifier, the outdoor air intake, the exhaust air discharge, and the duct routes.

Suspended ceilings were available only above the entrance areas of the rooms. This constraint led to the use of supply grilles utilizing the Coandă effect.

The ductwork had to fit within the available ceiling voids without compromising the interior design or requiring unnecessarily invasive construction work. Construction works themselves were outside the contractual scope of Marquis Intelligence.

Protecting the existing interior during installation was equally important. This included the elevator and common corridors, as well as the apartment’s flooring, furniture, and other interior finishes.

Ventilation Design Calculations

Marquis Intelligence designed the ventilation system in accordance with DIN 1946-6. The calculations covered minimum ventilation for moisture protection, reduced ventilation, nominal ventilation, and intensive ventilation.

The manufacturer’s design software calculated a nominal airflow of 184 m³/h and an intensive airflow of 239 m³/h. However, calculations alone cannot replace professional judgment about the specific characteristics of each project.

For that reason, the final design used a ventilation unit with a higher capacity than the calculated minimum requirement.

The team determined airflow rates according to the intended use of each room and balanced them across the apartment. Fresh air enters the bedrooms and dining area. Extract air leaves through the kitchen, bathrooms, and other spaces with higher moisture and odor loads.

The team also coordinated the ventilation system with the apartment’s air-conditioning system.

Airflow balancing takes place centrally through balancing valves on the supply and extract manifolds. This is one of the key advantages of the installed system.

Heat Recovery

The central ventilation unit uses a high-efficiency counterflow plate heat exchanger.

Supply and exhaust air pass through separate channels and do not mix. Heat transfers through the heat exchanger surfaces from one air stream to the other.

SEE ALSO: Plate or Rotary Heat Recovery Units in Residental Central  Ventilation?

The ventilation system provides the required quantity and quality of fresh air, while indoor temperature is maintained by the heating and cooling systems.

Air Treatment

Marquis Intelligence installed a dedicated filtration chamber upstream of the central ventilation unit. It contains a HEPA H14 filter and a molecular filter.

The HEPA H14 filter captures extremely fine airborne particles. The molecular filter reduces certain gaseous pollutants and unpleasant odors.

High-efficiency filtration also increases airflow resistance and pressure drop. For that reason, the team had to verify the available fan static pressure and assess the filtration chamber’s effect on the overall airflow.

A bipolar ionization system provides an additional stage of air treatment. It operates on the principle of dielectric barrier discharge (DBD). The ionization unit is installed in the supply air plenum immediately upstream of the distribution manifold. From there, the system distributes ionized air throughout the apartment.

The system also includes a steam humidifier, in accordance with the client’s requirements and needs.

During commissioning, the team found that the water downstream of the building’s central water treatment system had insufficient electrical conductivity for stable humidifier operation.

The humidifier water supply was therefore reconnected directly to the municipal water main. Measurements confirmed that the water conductivity met the manufacturer’s requirements for reliable operation.

This detail shows why a central ventilation system cannot be designed in isolation from other building services.

Existing Local Exhaust Systems and the Central Ventilation System

The kitchen range hood operates independently of the central ventilation system.

It operates intermittently and at airflow rates significantly higher than those required for continuous apartment ventilation. The existing bathroom exhaust fans also remained in operation. At the same time, the central ventilation system has its own dedicated extract points.

This arrangement separates three functions: continuous ventilation of the apartment, intermittent boosted exhaust from the bathrooms, and separate extraction of cooking vapors and kitchen emissions.

Internal and External System Verification

The design and installation passed through several levels of professional review.

A Mechanical Engineer prepared the ventilation calculations. A licensed consulting engineer then reviewed the engineering design and technical documentation.

The project parameters were also submitted to the equipment manufacturer. The manufacturer processed them using its centralized engineering software in Germany.

This review covered total and individual airflow rates, supply and extract air distribution, ventilation unit selection, and compatibility with the manufacturer’s technical requirements.

After installation, Marquis Intelligence submitted photographic documentation of the completed system to the manufacturer. The manufacturer then reviewed the equipment positioning, component interconnections, and key installation details.

The verification process therefore included engineering calculations, review by a licensed engineer, technical verification by the equipment manufacturer, and inspection of the completed installation.

Airflow Verification

Following system commissioning, the team measured airflow at the intake grille of the ventilation chamber. During the measurement, the heat recovery unit operated in Boost Mode.

The team used professional airflow measurement equipment. They divided the grille surface into six equal measuring zones and took measurements at three points within each zone.

After applying a 5% correction factor for possible external influences, the corrected airflow rate was 428 m³/h.

The measurement confirmed the airflow achieved at the intake side of the ventilation chamber in Boost Mode with clean filters.

Virtually Silent Operation

Supplying the required quantity of fresh air is not enough to ensure a high-quality ventilation system. Air distribution within the occupied spaces is equally important.

In this apartment, the system operates virtually silently. Occupants do not perceive noticeable airflow.

This result depends on proper duct sizing, appropriate air velocities, a sufficient number of supply terminals, correct terminal positioning, and precise system balancing.

Independent Indoor Air Quality Measurements

After approximately 24 hours of continuous system operation, with all windows kept closed, an independent scientific institute carried out instrumental measurements of the apartment’s indoor air quality.

Using professional monitoring equipment, the following indoor air quality parameters were recorded:

• CO₂: 668–889 ppm
• TVOC: 207–246 ppb
• Formaldehyde: 16 ppb
• Fewer than 50 particles/cm³ within the measured particle size range of 0.3–10 µm
• Ozone (O₃), sulfur dioxide (SO₂), and nitrogen dioxide (NO₂): not detected

CO₂ concentrations remained within an appropriate range even in rooms occupied by considerably more people than assumed in the original design calculations. For example, a home office designed for one occupant was occupied by four people during part of the testing period, yet the measured CO₂ concentration reached only 889 ppm.

SEE ALSO: CO₂ in Your Home – Is It There and Where Does It Actually Come From?

No measurable concentration of ozone was detected during system operation.

A particle concentration of less than 50 particles/cm³ corresponds to very clean indoor air, according to the classification applied in the laboratory report. It should be noted that this result refers to the instrument’s measurement range of 0.3–10 µm.

The report further states that the combined effect of ventilation, filtration, and bipolar ionization would be expected to become even more pronounced under conditions of poorer outdoor air quality.

What Does This Project Demonstrate?

This project shows that a central ventilation system can also be retrofitted into an apartment in an existing multi-storey residential building. However, the building must provide suitable spatial and technical conditions.

Such a solution involves far more than installing a central ventilation unit.

The configuration and total cost of the system depend on the building itself and the client’s requirements. Other important factors include the required airflow, the level of air treatment, duct routing, the locations of the outdoor air intake and exhaust air discharge, installation conditions, and additional system components.

SEE ALSO: Residential Ventilation by Marquis Intelligence
SEE ALSO: FAQ – Home Ventilation

What Determines the Price of a Central Ventilation System?

The price of a heat recovery unit is not the same as the cost of a complete ventilation system.

A fully engineered solution includes much more than the equipment itself. It also includes engineering calculations, system design, ductwork, installation, airflow balancing, commissioning, and performance verification.

One of the most important aspects of this project is that the team did not evaluate the result solely on the basis of the installed equipment.

The verification covered the engineering design, system configuration, completed installation, achieved airflow, and key indoor air quality parameters.

Verifying the performance of a central ventilation system is the final and indispensable stage of project implementation. It confirms whether the completed system operates in accordance with the engineering design requirements.

Long-term reliable operation also depends on regular maintenance. The best continuity is achieved when the company that designed, installed, and commissioned the system continues to maintain it in accordance with the manufacturer’s recommendations and actual operating conditions.

This article is part of the Marquis Intelligence “Mini Case Studies” series.
Document ID: MI-MCS-09.3Q-26
Document Title: Mini Case Study: Verifying the Performance of a Central Ventilation System in an Apartment

The post Mini Case Study: Verifying the Performance of a Central Ventilation System in an Apartment appeared first on Marquis Intelligence.

Its foundations were laid much earlier, at a time when microorganisms were not yet fully understood and air could not be analyzed using modern instruments. Yet, in the story of the development of air hygiene, two days in August symbolically connect three pioneers of this field.

Two Days in August That Changed the History of Medicine

The history of medicine is filled with remarkable discoveries. It is rare, however, for just two days on the calendar to connect three individuals whose work would fundamentally change the way we think about health, hospital hygiene, and the environments in which patients are treated.

In the history of medicine, 12 and 13 August symbolically unite three people who probably never considered themselves part of the same story and whose lives never crossed.

Each of them addressed a different problem. One focused on the hospital environment. Another studied the transmission of disease. The third transformed surgical practice. Today, we know that each of them, in his or her own way, contributed to the understanding of what we now call air hygiene.

Air Hygiene and the Beginning of Antiseptic Surgery

On 12 August 1865, the Scottish surgeon Joseph Lister performed an operation on an eleven-year-old boy using an antiseptic technique. The boy had suffered a severe compound fracture of his leg. At that time, injuries of this kind almost invariably resulted in amputation or death from infection.

Lister’s antiseptic procedure proved successful. The boy recovered, and this event marked the beginning of a new era in surgery. It was a turning point that would soon confirm that the observations of Ignaz Semmelweis had been far ahead of their time.

Lister subsequently extended his antiseptic approach to wounds, surgical instruments, the operating field, and even the air within the operating theatre. The spraying of carbolic acid represented the first documented attempt at chemical air disinfection in the history of medicine.

A Profound Historical Injustice

Only one day later, on 13 August 1865, Ignaz Semmelweis died.

The man who had spent years trying to convince his colleagues that simple hand hygiene could save thousands of lives did not live to see medical practice confirm the fundamental principle for which he had fought. The irony of history was even greater: he died of a systemic infection – the very condition against which he had devoted most of his professional life.

Exactly forty-five years later, on 13 August 1910, Florence Nightingale also passed away.

Thus, just two dates on the calendar symbolically connect three pioneers whose ideas continue to shape the way we think about hygiene, infection prevention, and the quality of the hospital environment.

Three Different Paths Toward the Same Goal

At first glance, Joseph Lister, Ignaz Semmelweis, and Florence Nightingale worked in completely different fields.

Their methods differed, as did the problems they sought to solve. Even their conclusions were reached under entirely different circumstances. Yet all three were trying to answer the same question: What can we change in the patient’s environment to save more lives?

Today, this question seems perfectly natural. In the mid-nineteenth century, it was revolutionary.

1. Joseph Lister – When Theory Became Practice

Unlike Florence Nightingale and Ignaz Semmelweis, Joseph Lister was not primarily known for statistical analyses. His greatest contribution was transforming emerging scientific knowledge into practical medicine.

Inspired by Louis Pasteur’s work on microorganisms, Lister concluded that infection was not an inevitable consequence of surgery. If microorganisms could be prevented from entering a wound, infection could also be prevented.

He began using carbolic acid to antiseptically treat wounds, surgical instruments, and the operating field. Later, he even attempted to disinfect the air by spraying carbolic acid throughout the operating theatre.

From today’s perspective, it is clear that this was not the ultimate solution. Nevertheless, it represented the first serious effort to regard the air in a healthcare environment as a factor capable of influencing clinical outcomes.

Lister did more than embrace a new scientific concept. He demonstrated that it could be successfully applied in everyday medical practice.

SEE ALSO: Lord Lister and the First Chemical Air Disinfection

2. Ignaz Semmelweis – When the Numbers Spoke

While Florence Nightingale was studying the hospital environment, Ignaz Semmelweis was trying to understand why maternal mortality was dramatically higher in one maternity ward than in another.

He did not begin with a theory but with careful observation and analysis of numerical data. He compared outcomes, searched for differences, and rejected assumptions that were inconsistent with the evidence. After introducing mandatory hand disinfection, maternal mortality declined dramatically.

Today, hand washing seems self-evident. However, in the middle of the nineteenth century, it represented one of the greatest revolutions in the history of medicine.

Semmelweis had no access to modern microbiology. He could not measure aerosols. He knew nothing about PM₂.₅, VOCs, or HEPA filtration. Yet he understood something far more fundamental. He reached a conclusion that would permanently change medical practice: The chain of disease transmission can be broken.

That principle remains just as important today.

SEE ALSO: Ignaz Semmelweis: The Savior of Mothers and Newborns

3. Florence Nightingale – When the Hospital Became Part of the Treatment

Florence Nightingale did not view the hospital merely as a place where patients were treated. She regarded it as an integral part of the healing process itself.

During the Crimean War, she encountered overcrowded hospital wards, inadequate ventilation, poor sanitary conditions, insufficient natural light, and inefficient organization of care. Rather than accepting these conditions as inevitable, she began to observe, record, and compare the outcomes.

She did not believe assumptions. She believed data. Her statistical analyses demonstrated that improvements in sanitary conditions – including better ventilation and access to fresh air – were accompanied by a significant reduction in mortality.

At a time when the role of microorganisms was only beginning to be understood, Florence Nightingale demonstrated that the environment surrounding the patient could have a decisive influence on treatment outcomes.

SEE ALSO: Florence Nightingale’s Lamp Brings a Glimmer of Hope

What Truly Connected These Three Pioneers?

Their contributions to hygiene and the hospital environment took different forms:

•   Lister transformed surgical practice.
•   Semmelweis interrupted the transmission of infection through hand hygiene.
•   Nightingale transformed the entire hospital environment.

What united them was their way of thinking. They noticed what others overlooked, measured outcomes, and trusted evidence more than established beliefs. Then, based on those findings, they changed medical practice.

This is precisely how modern air hygiene solutions are developed today.

The process does not begin with the assumption that a particular technology is the best. It begins with the problem itself – with understanding the sources of contamination, the potential routes of transmission, and the desired outcome. Only then is the appropriate solution selected.

Air Hygiene Today

Since the time of these pioneers, medicine has made extraordinary progress. International cleanroom standards have been established. Ventilation systems have become increasingly sophisticated. High-efficiency filtration, indoor air quality monitoring, and numerous technologies for further improving air quality have been developed.

Today, air hygiene is no longer limited to reducing the presence of microorganisms.

It encompasses the control of airborne particles, chemical pollutants, and unpleasant odors; the provision of appropriate ventilation and airflow patterns; and the prevention of unwanted pathways of contamination between different areas.

The COVID-19 pandemic served as a historic reminder that air is more than simply the medium in which we exist. Under certain conditions, it can also become an important route for the transmission of infectious aerosols.

At the same time, numerous scientific studies have further highlighted the importance of air quality for overall health, including respiratory diseases, cardiovascular health, mental well-being, reproductive health, and many other aspects of human health.

Examples from Contemporary Practice

Today, these historical lessons have very practical applications.

For more than three decades, Marquis Intelligence has participated in the design and implementation of air quality improvement solutions across a wide range of facilities, including healthcare institutions.

These projects include the Institute for Cardiovascular Diseases of Vojvodina in Sremska Kamenica, the Clinical Centre of Vojvodina in Novi Sad, the Institute of Public Health of Montenegro in Podgorica, as well as numerous other public and private healthcare facilities.

Interestingly, the implementation of one of the advanced air treatment technologies in healthcare facilities began with education.

From Education to Practical Implementation

During a professional presentation organized by Marquis Intelligence on advanced technologies for improving air hygiene, a consulting engineer involved in the design of the Clinical Centre of Vojvodina attended the event.

Interested in the potential application of dielectric barrier discharge (DBD) technology within ventilation systems, he invited the Marquis Intelligence engineering team to deliver an additional presentation at his design office. Shortly thereafter, another presentation was organized for representatives of the healthcare institution itself.

Following the official opinion issued by the competent professional authority, a decision was made to implement this technology within the central ventilation systems of the new hospital building.

The journey from a new idea to its practical application has changed very little over the past century and a half.

Even today, progress depends on professional dialogue, scientific evidence, openness to new knowledge, and the willingness to improve established practice.

SEE ALSO: Mini Case Study: Impeccably Clean Air in a Hospital in Novi Sad

Today, We Continue to Ask the Same Question

Florence Nightingale, Ignaz Semmelweis, and Joseph Lister did not have access to modern instruments. They could not measure PM₂.₅ concentrations or monitor indoor air quality in real time. High-efficiency filtration systems and international cleanroom standards did not yet exist.

Nevertheless, they possessed what remains the foundation of all serious science and engineering:

•   they observed carefully;
•   they asked questions;
•   they monitored the results;
•   they changed practice when evidence demonstrated that a better solution existed.

Perhaps that is precisely why the symbolism of 12 and 13 August remains so powerful.

Within the span of just two days on the calendar, history forever linked three individuals who demonstrated that health depends not only on the medicine we practice, but also on the environments we create.

At Marquis Intelligence, we continue to work according to the same principle.

It is not enough simply to deliver air into a room. We must understand how it behaves, how it moves, and how it affects the people who breathe it.

Perhaps this is the most enduring message shared by Florence Nightingale, Ignaz Semmelweis, and Joseph Lister.

This article is part of the “Learn More About Air Through History and the People Who Shaped It” series from the Marquis Intelligence Archive.Document ID: MI-LAH-013.26 – Air Hygiene: Three Pioneers, Two Days, and One Goal

The post Air Hygiene: Three Pioneers, Two Days, and One Goal appeared first on Marquis Intelligence.

Her responsibilities gradually expanded across engineering and business. They now include design, product development, technical solutions, proposal preparation, sales, negotiations, contracting, project delivery, and service. Her work also covers marketing, website development, SEO, and technical writing.

This is the story of how her engineering role grew alongside the company, its projects, and the air quality market.

Earlier Professional Experience

Before joining Marquis Commerce, Gordana worked as Chief Investment and Maintenance Engineer at Dijamant. The company was a major Serbian edible oil producer based in Zrenjanin.

At the time, Dijamant employed around 1,500 people.

In 2005, Marquis Commerce delivered a turnkey project at the Dijamant production plant. The scope covered design, manufacture, supply, installation, and commissioning of a flue gas extraction and purification system.

The system included an electrostatic precipitator, continuous particulate emissions monitoring, an energy recovery unit, and an ash extraction system.

Gordana represented the client as Supervising Engineer. Serbia had only recently introduced professional engineering licences for this type of work. Such licences were still uncommon in manufacturing companies. Gordana had already obtained the required licence.

After the project, I invited Gordana to join Marquis Commerce.

She accepted.

From a Large Industrial Enterprise to a Micro Company

The move took Gordana from a large corporation with clearly defined roles and organisational structures to a micro company. In the smaller company, each person carried a much broader range of responsibilities.

One of her closest colleagues at Dijamant, Momčilo Ćuk, described the transition in a remark we still remember. He said: “Vladimir, you came here, installed the equipment, took our best engineer, and now you’re leaving.”

Gordana did not leave Dijamant because she lacked opportunities. She believed her professional development would progress more slowly within a large industrial organisation.

Dijamant repeatedly invited her to return, even after the company changed ownership. She declined the offer from the new Croatian management.

Expectations of a Small Team

A small engineering company offered greater flexibility and independence. It also gave Gordana direct influence over technical solutions.

At the same time, the work brought far greater personal responsibility.

Gordana believed she had enough technical knowledge and independence to build professional security outside a corporate structure. The position she left in a large industrial company could provide stability for someone else.

She did not expect the work to be easier. She chose a less predictable and more direct form of professional responsibility.

Technical Director from Day One

From her first day at Marquis Commerce, Gordana managed technical solutions, system design, and proposal preparation.

In a small engineering company, technical work soon extends into sales, procurement, contracting, project delivery, commissioning, and service.

Without specialised departments, one person often covers the entire process. Gordana had to understand the client’s problem, develop the solution, and verify its feasibility. She also estimated costs, prepared proposals, joined negotiations, and followed manufacturing and delivery. On site, she resolved problems and later verified system performance.

This is how her role evolved. Her title remained unchanged, but her responsibilities became broader and more complex.

Creativity Beyond the Arts

People often associate creativity with art, design, or aesthetic expression. Yet creativity also plays an important role in engineering, work organisation, and problem-solving.

For Gordana, creativity extends beyond technical writing and selecting topics for the company blog. She uses it to develop technical solutions, prepare documents, design procedures, create tracking spreadsheets, and improve workflows. It also helps her find new approaches to problems in the field.

This creativity complements engineering precision. It allows her to move beyond standard approaches while keeping each solution technically sound and practical.

The First Project at Marquis Commerce

One of Gordana’s first projects at Marquis Commerce focused on air quality in the production of herbal preparations and dietary supplements sold under the Todoxin brand.

The solution combined a Bioclimatic air treatment system based on dielectric barrier discharge (DBD) with an HB Cotes desiccant duct dehumidifier.

The project succeeded and immediately showed what work in a small engineering company required. Gordana carried direct responsibility from solution development and commissioning to performance measurement and long-term maintenance.

Projects Without Ready-Made Answers

Over the past two decades, Gordana has led or directly contributed to many engineering projects.

Some stood out because of their size. Others involved technological complexity, commercial risk, or difficult implementation conditions. Gordana particularly valued projects for which no simple, predefined answer existed.

They all had one thing in common. She approached each project with the same sense of responsibility. She also felt considerable apprehension whenever the time came to commission the system and measure results carrying the Marquis Commerce name.

London City Airport and Static Electricity

A section of London City Airport, including the customs area, had a serious static electricity problem. Employees frequently reported unpleasant electrostatic discharges.

The challenge covered a large area. An existing central ventilation system served that space.

During one project presentation, Gordana proposed using bipolar ionisation based on dielectric barrier discharge to neutralise the static charge.

Industrial facilities often use bipolar ionisation to control static electricity. Applying it through a large airport ventilation system created a different engineering challenge.

The system supplied air through nozzles installed about four metres above the floor. The airflow cross-section narrowed inside the nozzles, which increased air velocity. As a result, positive and negative ions could recombine before reaching the occupied zone.

Together with Professor Nenad Sakan, we simulated ion distribution throughout the space. We then assessed whether enough ions could reach the occupied zone.

We implemented the system and eliminated the static electricity problem. The project showed how an established technology could solve a problem for which no standard catalogue solution existed.

SEE ALSO: Marquis Intelligence Solution for London City Airport (UK)

Knjaz Miloš: A Centralized Air Sterilization System

For Knjaz Miloš, Marquis Commerce designed, manufactured, and installed a centralized multi-stage air sterilization system serving the air space above the company’s 100-ton water storage tanks – one of the most critical points in the production process from the perspective of the HACCP system.

The central stainless-steel unit, together with its automation system, was designed with both duty and standby configurations to ensure uninterrupted operation of this process-critical installation.

Today, the system continues to be maintained by the Marquis Commerce technical team and has demonstrated significant advantages over the previously installed solution.

The Largest Project We Cannot Discuss in Detail

The largest project in the company’s history in financial terms involved equipping three manufacturing plants on another continent. Because the project is covered by a confidentiality agreement, we cannot disclose the client, locations, or technical details. The project required highly complex technical and commercial negotiations, manufacturing, international logistics, and strict adherence to project deadlines. All contractual obligations were completed exactly as agreed.

The Development of the PHOENIX Exhaust Air Purification System

Shortly after Gordana joined Marquis Commerce, the development of the PHOENIX exhaust air extraction and purification system accelerated significantly. Gordana was primarily responsible for its technical concept and engineering development.

PHOENIX is not a standard product with the same configuration for every installation. Each solution is individually engineered according to the source of contamination, airflow rate, temperature, grease content, particulate load, smoke and odor characteristics, available installation space, and site-specific requirements.

Its development involved integrating multiple air purification stages, sizing treatment chambers, balancing pressure losses, designing the control philosophy, and ensuring convenient maintenance access. Over time, PHOENIX systems became particularly well known for the treatment of exhaust air from commercial kitchens.

SEE ALSO: FAQ – Extraction and purification of exhaust air from kitchen hoods
SEE ALSO: Commercial Kitchen Exhaust Ventilation: From Fire Risk to Safe Operation

The Most Challenging Period at Marquis Commerce

One of the most difficult periods since Gordana joined Marquis Commerce was undoubtedly the COVID-19 pandemic.

Almost overnight, the market became flooded with air purification devices manufactured, marketed, and purchased by people with little understanding of indoor air quality, air purification technologies, or the conditions required for their proper application.

At the same time, restaurants and hotels either operated at reduced capacity or remained closed altogether. Equipment maintenance was postponed, while meetings, site visits, and the planning of new projects became severely restricted. Under such circumstances, it was necessary not only to preserve the company’s business operations but also to remain committed to sound engineering principles and responsibility for the actual performance of the systems delivered.

From Engineering to Marketing and Technical Content

Gordana’s versatility was not the result of a carefully planned career path. It evolved out of necessity.

When work began on developing the company’s new website, it became clear that external specialists could contribute to graphic design and marketing, but they could not independently explain the company’s complex engineering solutions. For this reason, Gordana became actively involved in defining both the website’s structure and technical content while simultaneously studying professional services marketing through Hinge Marketing University.

This work led to the creation of the Marquis Intelligence Blog, numerous case studies, and the company’s growing collection of FAQ articles. Over time, the website evolved into a comprehensive knowledge base dedicated to air quality, ventilation, and Marquis Intelligence engineering solutions.

From Technical Director to Co-Owner of the Company

On 1 November 2019, Gordana Blagić became the owner of a 40% equity stake in Marquis Commerce.

This change in ownership did not mark the beginning of her responsibility for the company. She had already been carrying that responsibility for many years through technical leadership, product development, client relations, and participation in key business decisions. Becoming a co-owner simply formalized the role she had long fulfilled in practice.

SEE ALSO: FAQ – Identification and core details of Marquis Commerce

Twenty Years of Growth

Over the course of two decades at Marquis Commerce, Gordana Blagić has integrated technical management, product development, project implementation, negotiations, technical service, marketing, and the company’s professional positioning into a single, cohesive role.

Perhaps the best way to describe her contribution is through her approach to engineering itself: understand the problem, develop a technically sound solution, and verify its performance under real operating conditions.

This article is part of the Marquis Intelligence series presenting the people, expertise, and achievements behind the company’s work.
Document ID: MI-PROM-26.022 – Twenty Years of Gordana Blagić at Marquis Commerce

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