We’re Hiring at Indoor Science! Learn more about our Job Openings.

How can I prevent IAQ problems before they happen?

preventing IAQ problems

Every week we perform indoor air quality assessments for all different types of properties – residential, commercial, governmental, and industrial. By the time we are on-site, the occupant typically has some concerns that they believe are related to indoor air quality. Sometimes the occupant has a general sense of what the issue could be and other times the cause is less apparent.  This blog post will cover common IAQ problems that may be occurring in your property and how you can prevent them from happening in the first place. 

Source Control 

The best way to prevent IAQ problems is by stopping them at the source. This may seem obvious but as you go about your daily routine, you may not realize that you may be introducing harmful contaminants into your space. For example, volatile organic compounds (VOCs) are chemicals that can be emitted from new building materials, new carpeting, new furniture, personal care products, cleaning products, and even essential oils. Elevated levels of VOCs can cause respiratory problems and other health effects. To prevent high levels of VOCs, consider using “green” products or those that do not contain harsh chemicals.  Also, limit or eliminate the use of fragrant air fresheners or diffusers and air out new furniture or new carpeting as much as possible. 


A major problem in any property is moisture problems! Leaks from a roof, water intrusion from a window, or water seepage through the foundation are all very common problems that should be addressed immediately.  These types of water issues are usually obvious but one moisture-related problem is not so obvious: humidity. I’ve been to several properties where condensation is visible on windows, on steel kitchen exhausts, around supply registers, or around bathroom exhausts. Condensation can cause mold growth on surrounding drywall or wood materials. Typically the problem is with humidity levels. 

To prevent condensation problems, humidity levels should generally be below 35% in freezing weather and below 60% in the summer months. When it gets humid in the spring, remember to turn off any humidifiers attached to the HVAC system to limit indoor humidity.  In any basements, remember to operate a dehumidifier to remove excess humidity during the spring and summer. While you’re down there, make sure the sump pump has a working back-up battery in case of a power outage.


To save on energy costs, new construction buildings are now more tightly built. This helps keep buildings warm in cold weather and cool in the warmer months. Unfortunately, adequate ventilation may not have been a priority when designing the property. Proper ventilation lowers carbon dioxide levels, helps dilute indoor contaminants, and it exhausts airborne contaminants from the space. To improve the ventilation in homes, introduce outdoor air with an outdoor air intake attached to the HVAC system. The simplest solution to increase ventilation would be to crack open a window whenever the weather allows. To improve the ventilation in commercial buildings, ensure that energy-saving measures haven’t resulted in outdoor air intakes being closed. While outdoor air is typically better than the indoor air, you should refrain from opening windows when the humidity levels outside are elevated. It is much better to bring in that outdoor air through the HVAC system where it will get filtered and dehumidified.


To prevent IAQ problems, we suggest going through your property and following the recommendations in this blog post. For more information check out this article. Remember to keep things dry, ventilate as much as possible, and avoid introducing contaminants. If you need more a more in-depth assessment, consider contacting the professionals at Indoor Science.

Ian Cull

Ian Cull is a nationally recognized expert in the field of indoor air quality. He is the Chief Science Officer of Indoor Science, a company he started in 2004. He speaks around the world on air quality topics and is a training provider of the Indoor Air Quality Association. Mr. Cull is a Licensed Professional Engineer (PE) and Certified Industrial Hygienist (CIH). His degree is in Environmental Engineering from the University of Illinois - Urbana Champaign. Mr. Cull has developed 50 air quality related courses for the IAQA University and is the author of the book, “Fundamentals of Mold Remediation”. In his words… “Besides being passionate about indoor air quality, I enjoy cycling, music, the Chicago Bulls, and having fun with my three kids.”

2 thoughts on “How can I prevent IAQ problems before they happen?

    How do you convince the property manager of an apartment complex (that is not smoke free) that indoor air quality is a problem?Many people now vape inside their apartments. What are the concerns with indoor vaping?

    Hello Catherine,

    An indoor environment that permits occupants to smoke increases particles (particulate matter) in the air. You may want to consider measuring particles in the apartment complex. Vaping can also emit particles and chemicals (volatile organic compounds) in the air.

    Thank you for commenting!