Blog
HVAC and IAQ System Maintenance – The Pillar of Reliability
Modern buildings include numerous technical installations that often go unnoticed by users. Most people typically think of electrical systems, plumbing, and fire protection. However, heating, ventilation, and air conditioning (HVAC) systems increasingly form an essential part of the technical infrastructure, alongside integrated systems that ensure indoor air quality (IAQ). HVAC and IAQ system maintenance, therefore, requires far more attention and expertise than the maintenance of most other installations.
Marquis Intelligence does not provide general-purpose servicing. The company maintains exclusively the HVAC and IAQ systems and equipment it has designed and delivered. This approach ensures that every system continues to operate strictly within its designed performance parameters. For Marquis Intelligence, HVAC and IAQ maintenance is not an additional service, but an integral part of engineering responsibility.
Why HVAC and IAQ Systems Matter to Building Users
Ventilation and air purification systems aim to provide a healthy and safe indoor environment. Still, many decision-makers continue to treat these systems as a luxury or an unnecessary expense. In practice, however, the opposite proves true.
HVAC and IAQ systems create controlled indoor conditions: they provide an adequate supply of fresh air, maintain stable, comfortable temperatures and humidity, and reduce concentrations of particles, gases, and unpleasant odors. In modern, energy-efficient buildings with high levels of insulation, these systems become a basic requirement for a safe indoor environment. Over time, their value is demonstrated by reliable operation and consistently stable air quality.
Marquis Intelligence Expert Team for HVAC and IAQ System Implementation
Marquis Intelligence specializes in the design and turnkey implementation of HVAC and IAQ systems. The same approach applies to complex commercial buildings and ventilation systems for houses and apartments, both of which require equally precise design and long-term reliability.
To deliver full service and ensure users remain satisfied with the performance of installed systems, the company also provides maintenance services. In fact, throughout 2025, HVAC and IAQ system maintenance clearly demonstrated the value these systems deliver to users.
HVAC and IAQ System Maintenance – Benefits for Users
Regular HVAC and IAQ system maintenance improves energy efficiency, ensures reliable, stable operation, and extends service life. At the same time, it provides the continuity of comfortable, healthy indoor conditions, which remain critical for building users.
That is why, when selecting technical devices and installations, it is essential to confirm the local availability of spare parts and the presence of authorized service support. These two factors form the foundation for a safe, long-term, cost-effective investment.
HVAC and IAQ System Maintenance – The Supplier’s Responsibility
Ventilation, heating, cooling, and indoor air quality systems form part of the complex technical infrastructure of modern buildings. Their efficiency depends not only on the quality of design, equipment, and installation – even though these elements remain essential for a sound technical solution.
In reality, system reliability and accurate operational results depend heavily on continuous, professional, and structured maintenance.
During 2025, Marquis Intelligence reinforced this insight through hands-on practice, analysis, and real-life cases. The company confirmed once again that HVAC and IAQ system maintenance represents one of the key pillars of long-term system functionality and, equally importantly, the quality of occupancy.
Maintenance Models – Different Approaches
A maintenance model must guarantee equipment safety and efficiency while staying aligned with acceptable risk levels and the user’s budget.
In Marquis Intelligence practice, the company often agrees to maintenance under a combined model. Equipment that requires more frequent maintenance, such as replacing mechanical filters in HVAC units, is covered by a scheduled preventive maintenance program. Meanwhile, the remaining equipment is inspected and serviced using an intervention-based model, meaning the team responds when a fault occurs.
Combined HVAC and IAQ maintenance models have proven to be the most acceptable option for users.
HVAC and IAQ System Maintenance – Market Shifts
It is always rewarding to confirm the design parameters of a new, technically flawless installation. However, it matters just as much that such an installation maintains the same efficiency over time and continues to serve reliably and over the long term, as expected by the user who placed their trust in it.
During 2025, Marquis Intelligence observed a clear market shift: decision-makers increasingly recognized HVAC and IAQ system maintenance as a key factor in investment decisions. In many cases, clients required explicit confirmation that qualified service support and original spare parts would remain available for at least the next five years before signing contracts for new installations.
Marquis Intelligence Growth in the Maintenance Segment
Additionally, in 2025, the company recorded a notable rise in interest for maintenance contracts – both for existing systems and for those still in planning or implementation phases. This trend confirms that clients now increasingly view maintenance as a core part of the technical solution, rather than a later “extra cost”.
As a direct result, Marquis Intelligence achieved a 30% increase in its share of maintenance revenue in 2025 compared to the previous year. Compared to 2020, the company achieved 100% growth.
More about Marquis Intelligence’s business activities in 2025 is covered in a previous blog post.
HVAC and IAQ System Maintenance – Performance Proof in Practice
In real operating conditions, users quickly recognize the difference between a system that exists only in a building and one that truly works.
If the supplier ends the relationship after handing over the system, the team loses valuable feedback on user satisfaction. In addition, without continued support, they often lose data on system functionality and performance throughout operation.
For Marquis Intelligence, the end of 2025 provided clear evidence – through HVAC and IAQ system maintenance delivered under the combined model described earlier – of just how vital these systems are to users.
Example: A Multi-Story Office Building for an IT Company in Belgrade
An IT company’s office building in Belgrade features two identical ventilation systems with integrated bipolar air ionization, serving the building’s two wings. During preventive service, the Marquis Intelligence team identified damage to several ionization tubes on one system. For safety reasons, the team temporarily removed them.
Until replacement, the team carried out air quality measurements. The results showed higher levels of volatile organic compounds (VOCs) and fine particles in the building wing with fewer active ionization tubes.
Example: The Skyline Tower in Belgrade
At the Skyline business tower, Marquis Intelligence installed 50 bipolar air ionization systems, bringing the total to 200 devices integrated into the building’s central HVAC systems. Although the devices included a self-cleaning function, the company clearly informed the client from the outset that regular maintenance was still required. Maintenance ensures system reliability, preserves efficiency, and maintains safe operation.
During a service inspection, the team detected an irregular operation on a device in the system. As a result, the team temporarily shut down the device. Shortly afterward, an employee whose workstation was in the zone served by that device reported a noticeable decline in air quality, unaware that the system was temporarily offline.
Conclusion
Marquis Intelligence does not treat HVAC and IAQ systems as products. Instead, the company treats them as long-term technical systems that require engineering responsibility. Only with proper, timely, and high-quality HVAC and IAQ system maintenance can these systems deliver the performance they were designed and installed to achieve.
Although HVAC and IAQ system maintenance remains demanding, user satisfaction is vital to Marquis Intelligence operations. Today, it stands as one of the company’s key business pillars.
This text forms part of a series of posts presenting the work and business results of Marquis Intelligence.
Document number: MI-PROM-26.018 – HVAC and IAQ System Maintenance – The Pillar of Reliability
