Preventative Maintenance Improves IAQ
HVAC in a building in some ways can be compared to the pulmonary system in the human body. HVAC allows for the exchange of air throughout a building. The HVAC regulates temperature and comfort for occupants. As system components age they can degrade and affect performance. Therefore, preventative maintenance improves IAQ and energy efficiency.

The EPA reports that we spend 90% of our time indoors and breath upwards to 3,000 gallons of air a day! The EPA also estimates that 1 out of 4 buildings in the U.S. are affected by sick building syndrome. The World Health Organization has that number at 1 in 3 buildings globally. Academic studies have found that poor IAQ directly impacts occupant health and productivity.

On the efficiency side HVAC systems consume 40% – 60% of a building’s energy. However, that consumption factors into as much as 80% of the annual operating cost of HVAC systems. Consider that just 3/16 of an inch of fouling across HVAC coils can drop the efficiency of that air handling unit (AHU) by 20%! It’s easy to see that kind of loss can drastically affect multiple efficiencies through the entire system.

So what can facility and engineering professionals do to keep the HVAC breathing easy? Let’s look through the entire HVAC system to see how preventative maintenance improves IAQ and energy efficiency.

Air Handling  and Packaged Equipment

One of the main areas of focus for optimizing the HVAC system should be the air handling equipment. The AHU and supply ductwork are the closest parts of the system to the occupants. Cleanliness of these components is critical to good IAQ. In large buildings there is often multiple AHUs supplied by a chiller. So, individual AHU performance can contribute to overall efficiency. Regular inspections and preventative maintenance improves IAQ and energy efficiency to create positive outcomes!

IAQ Considerations:

  • Keep coils, interior components (such as drain pans and fans), plenums and ductwork clean to reduce microbial proliferation throughout the system.
  • Encapsulate or better yet replace old insulation with a fiberglass free product

Performance Considerations:

  • Inspect coils, filter housing, cabinet and duct for leaks, repair if needed
  • Keep belts properly aligned and tensioned, replace when worn
  • Make sure dampers and fans are lubed and functioning properly

Dual Purpose:

  • Keep all heating, condenser and cooling coils clean for optimal airflow, static pressure and temperature transfer
  • Replace filters regularly for maximum hygiene, airflow and static pressure


The controls synchronize the interactions between the different components of HVAC equipment for optimal performance. Specialized IAQ sensors have the ability to link to the controls to identify potential issues and make a system request for corrective action. Any degraded part of the system can cause a chain reaction that affects overall operations.

  • Inspect all components to ensure they are fully operational
  • Repair, Restore or replace faulty parts before they fail
  • Immediately address alarms and forced status alerts
  • Perform routine diagnostic protocols and take recommended actions
  • Make sure all software and firmware is updated where applicable


Just like the AHUs, if chillers are not regularly maintained they can lose 1/5 to 1/4 of their specified efficiency. Therefore, they work longer and consume more energy to produce the amount of cooling needed.

Inspect, clean and calibrate the chillers on a routine basis to keep them running at peak performance.

Cooling Towers

Towers are another component in the HVAC system that can have dire consequences to other equipment as well as IAQ. For example, just a single degree increase in supply temperature can degrade the efficiency of the chiller by 2%-3%! Not to mention if cooling tower hygiene is compromised bacteria, like legionella, can seriously impact occupant health. This is another critical area where preventative maintenance improves IAQ and efficiency.

IAQ Considerations:

  • Keep the tower hygienically clean to minimize surface algae and suspended solids in the water
  • Treat water for biological growth and maintain suspended solid count within acceptable limits

Performance Considerations:

  • Inspect and clean spray nozzles, clearing clogs for proper operations
  • Make sure fan blades are clean and maintained
  • Keep drive belts properly aligned and tensioned
  • Clear all debris from fill to maximize heat transfer
  • Routinely monitor and calibrate fan and water-level controls

Regularly scheduled HVAC preventive maintenance improves IAQ and efficiency. That way occupants can remain comfortable, health and productive. Staying on top of HVAC maintenance also means the system will not use more energy than needed to do its job. Being proactive can also identify potential issues, reduce work orders and minimize risk of equipment failure. Routine checkups and maintenance are the prescriptions for good HVAC health. They let your building breathe easy so the equipment can have a longer lifespan.

For more information on setting up an Preventative Maintenance Program or our professional IAQ based mechanical service please contact Alan Wozniak at 1-800-422-7873 or use the form located here!