HVAC Insulation and Building IAQ


Building occupants are concerned with their health as it relates to the indoor environment. The ongoing pandemic only highlights the need for addressing IAQ issues. While anxiety about the spread of airborne viruses is high, other aerosols pose a threat to our health indoors as well. For example, how HVAC insulation affects IAQ is a question many facilities managers need to address in their buildings.

What is Fiberglass HVAC Insulation?

Fiberglass is in the insulation of most residential homes. It keeps buildings cool in the summer and warm in the winter. It’s placed behind walls and above ceilings. It insulates ventilation ducts as well as the air handling units (AHU) of HVAC systems.

The fine glass fibers used to make insulation degrade over time. Fibers come loose and travel through the air where oftentimes they get taken into the lungs. Of particular concern is the exposed fiberglass insulation found inside air handling units (AHU). When this material gets damp it sags and breaks down. The result is the distribution of fiberglass particles into the air stream. Not only do these particles threaten health, but mold and bacteria traveling through the ductwork do as well.

How Fiberglass Affects Our Health Indoors

While the connection between asbestos insulation exposure and lung cancer is documented, the health dangers of fiberglass insulation are not as clear. However, when the tiny particles of fiberglass get breathed in, at the very least, they irritate the nose and throat. HVAC insulation irritates the eyes as well as the skin when touched. It also acts as an asthma trigger. 

Coughing and sneezing may be enough to expel these particles, but long-term exposure presents a greater risk. This is why both OSHA and the National Insulation Association implemented a voluntary limit for fiberglass exposure in the workplace. One breathable glass fiber per cubic centimeter of air in a single eight-hour workday is the recommended limit. In addition to fiberglass, microbes and pathogens also travel through the air where they pose a health risk to all building occupants. 

Assessing How HVAC Insulation  Affects IAQ

Facilities managers concerned with how HVAC insulation affects IAQ have several options. For our part, WTI | Pure Air Control Services offers services and methods designed for improved building health. 

HVAC Hygiene Assessment

The first step in diagnosing IAQ issues is with an HVAC Hygiene Assessment. This includes a visual inspection of the coils, drain pan, ductwork, as well as air handling unit. Samples from the AHU undergo analysis by the Laboratory at WTI | Pure Air. These tests find traces of bacteria and fungi. At the end of the assessment, a final report guides the next steps needed to improve IAQ. 

Building Health Check

The Building Health Check is another evaluation that screens for allergens such as dust and mold. It includes the recording of floor and wall moisture, as well as temperature and humidity levels. The check includes the collection of air and surface samples to detect the presence of bacteria and mold. This affordable assessment is based on the building’s HVAC zones. It uses both field and laboratory assays to provide a detailed report on indoor biological conditions as well as building performance. At the end of the health check, a detailed report gives building managers the data needed to change how HVAC insulation affects IAQ.


After the initial evaluation, the next step is remediation. In many cases, this includes the PURE-Duct method. This system uses high-pressure air flow to knock loose debris from inside the ductwork. Once dislodged, a high-power vacuum system removes them. The result is cleaner, healthier air. In addition, replacing degraded fiberglass insulation with PURE-Cell reduces the negative way HVAC insulation affects IAQ. With this method, the fiberglass duct board is cleaned and encapsulated using antimicrobial paint. This method keeps fiberglass from entering the air stream as it minimizes dust buildup. It also prevents the insulation from sagging.

Learn More About How HVAC Insulation Affects IAQ

Keep the buildings under your care safe from the spread of airborne allergens and pathogens. For more information on how HVAC insulation affects IAQ and what you can do about it, contact WTI – Pure Air Control.