Multiple abbreviated terms related to Indoor air quality

The ABC’s of Indoor Air Quality

  • Date: 04-2022

There’s been a lot of talk lately about the quality of your indoor air and its role in preventing the spread of viruses and promoting overall health and wellness. Check out some articles (links provided below) that shed light on indoor air quality issues.

You’re likely to come across all sorts of terms – from HEPA filters to MERV ratings and everything in between. While you don’t have to become an expert overnight, it is important to arm yourself with some basic knowledge – the ABCs of indoor air quality – so that you can take the right steps toward creating a better indoor air environment for you and your family. Here are some key terms to be familiar with; these are listed in alphabetical order.

Air Quality: we measure air quality in terms of three factors – health, comfort, and safety.

  • Health: High levels of particulate matter, chemical pollutants, volatile organic compounds, and carbon dioxide could pose health hazards: a September 2021 study found links between poor indoor air that included these elements and cognitive function.
  • Comfort: It’s important to keep relative humidity below 48 percent to make your air more comfortable to breathe and to prevent mold growth. See below for more details on relative humidity.
  • Safety: Levels of carbon monoxide, which is known as the silent killer, need to be monitored.
Health, Comfort, Safety Test Chart

Disinfection: The process of eliminating microbes, viruses, and bacteria on surfaces and in the air. Be careful using aerosol sprays that can irritate sensitive breathers and watch out for harmful ingredients. At Green Home Solutions, we offer three levels of disinfection so you can breathe with confidence: General; Enhanced; and Hospital-Grade. Check out this site for more details.

Filtration: The process of using a physical barrier to capture particles and particulate matter. Two primary options include:

  • HVAC system filters, so that the air circulating through your HVAC ductwork is filtered before making it to your living spaces. We recommend using the highest rated MERV filter that your HVAC system will allow (read on to find out what MERV means).
  • Portable, room filtration systems, which, when sized appropriately, improve the quality of your indoor air. Use ones that have HEPA filters (see below!), and be wary of low-cost desktop models or ones that use ionic mechanisms, which can emit harmful ozone.

HEPA Filter: High Efficiency Particulate Air filter that, as defined by the U.S. Department of Energy, can remove 99.97% of dust, pollen, mold, bacteria, and airborne particles that are 0.3 microns (or larger).

Humidity: Relative humidity, expressed as a percentage, is the measure of the amount of water vapor in your air.  Maintaining proper humidity levels (below 48%) in your home is one key for keeping mold at bay and for making the air more comfortable to breathe. The National Institutes of Health published a January 2020 study that found that individuals who spent time in an ideal range set of relative humidity experienced lower stress responses and better sleep quality. Use a hygrometer to monitor humidity levels and ensure that they remain in the ideal range set. More than one hygrometer might be needed depending on the size of your home.

MERV: Minimum Efficient Reporting Values, as defined by the American Society of Heating Refrigerating, and Air Conditioning Engineers (ASHRAE), describe how well a filter captures particulates. The EPA provides a handy chart that correlates the MERV rating with its ability to filter particles as measured in microns.

Ventilation: The process of using outside air to lower the concentrations of indoor air pollutants, and the process of using a fan to exhaust indoor air to the outside. Two easy ways to ventilate: open the windows (if weather permits and pollen counts aren’t high that day) and use those exhaust fans in your kitchen and bathroom. You can also look into heat recovery ventilators and energy recovery ventilators, which, according to the Home Ventilating Institute, promote air exchange.

Speaking of exhaust…. Although this certainly isn’t an exhaustive list of indoor air quality terms, it helps you get started with some foundational knowledge. We can also help you get started with a free indoor air quality assessment that includes both a visual inspection and an air quality test that measures health, comfort, and safety. Call us today!

End Notes:

  • NPR, “Better ventilation would create a healthier workplace – but companies have to invest” from 19 April 2022:
  • New York Times, “The White House emphasizes the importance of indoor air quality as the pandemic moves into a new phase” from 28 March 2022:
  • NPR, “Better air in classrooms matters beyond COVID. Here’s why schools aren’t there yet” from 14 March 2022:
  • New York Times, “Is bad indoor air quality dulling your brain” from 16 September 202:
  • For details on the study about the link between indoor air quality and cognitive function:
  • For the three levels of disinfection that Green Home Solutions offers:
  • For more on the National Institutes of Health publication on the relative humidity study:
  • For EPA’s chart explaining the MERV rating:
  • For more on the Home Ventilating Institute’s description of ventilation systems: