clock menu more-arrow no yes mobile

Understanding Indoor Air Quality

Ask This Old House home technology expert Ross Trethewey and plumbing and heating expert Richard Trethewey discuss indoor air quality, what it is, and how to measure it.

What is Indoor Air Quality?

Indoor air quality (IAQ) is a description of different compounds and pollutants that comprise the air inside a home or building, which includes everything from particles released from cooking, CO2 from humans breathing, VOCs from cleaning products, etc.

IAQ has become more top of mind for HVAC engineers because homes are tighter and keep air inside the building for significantly longer than in years past.

How to Keep Air Clean

To keep clean air in an airtight home, consider installing an energy recovery ventilator (ERV) which can act like lungs for the building, bringing fresh air in without losing any of the heating or cooling attached to it.

There are a couple different monitors designed to measure and keep track of common pollutants in the air, including radon, CO2, VOCs, etc., that can be installed in a home and monitored via phone.


Ross and Richard tested out a couple different IAQ monitors, including one made by Foobot, Airthings Wave Plus, which is manufactured by Airthings, Awair, and Hobo, which is manufactured by Onset.

Most homeowner-friendly IAQ monitors have similar price points, but Ross suggests carefully reading the reviews of the monitors before investing in one, since they have different quality levels of sensors and some are more accurate than others.