Our homes are becoming more air tight to reduce energy costs and that's good. But it means many of the gaps where older houses allowed the exchange of indoor and outdoor air have been plugged. That's why homeowners need to learn what is needed to protect indoor air quality (IAQ) in their homes.
The government program, Indoor Air Quality (IAQ), helps homeowners, builders and remodelers focus on protecting the indoor air quality of homes. The program is similar to the EnergyStar and WaterSense programs.
What Causes Poor Indoor Air Quality?
Poor indoor air quality is due to a combination of the pollutants identified in the pie chart above. Many of these you're familiar with and others not. That's why homeowners, myself included, need to learn more about protecting indoor air quality in our homes.
- Chemical gases and odors like those emitted by paints for many years.
- Particles and allergens from dust to pet dander and more.
- Germs and infectious agents like mold, the flu virus and now the coronavirus.
When too little outdoor air enters a house, pollutants can accumulate to unhealthy levels. The more airtight your home, the more pollutants unless you take steps to eliminate them. Your HVAC system won't do this for you. It only circulates the air inside your home. To remove pollutants you can open windows daily or add a special mechanical means of ventilation.
Can I Check the Air Quality in My Home?
You have many options for protecting indoor air quality in your home. There are ways to test your home one time for air pollutants like radon and mold. Alternatively, you can purchase air quality monitors for specific pollutants. You need to do your homework and decide what you want to monitor as devices don't test for everything.
- DIY test kits exist for radon, mold and lead, and you can find them on Amazon. Below is one of the four mold kits used after this house flooded, to confirm a mold problem that required professional testing.
- Professional testing is required when you have severe problems. These cost hundreds of dollars but when your family's health is at risk, you know it's required. Start with the DIY kits and use their results to identify when additional testing is required.
- Air quality monitors that test for one or multiple types of air pollutant are flooding the market. Determine what you want to test for:
- Volatile organic compounds found in building materials like plywood, particleboard and glues; formaldehyde found in drapes, fabrics and some foam insulation. Burning fuels such as gas, wood and kerosene will also put VOCs into the air, as will tobacco products.
- Humidity is used to identify when your home is at risk of supporting the growth of molds which are present everywhere. You want to keep your home below 60%.
- Particulate matter varies in size, shape and composition. EPA (learn more) is most concerned about particles smaller than 10 micrometers in diameter because they are inhalable, so they can affect the heart, lungs and in some cases cause serious health effects.
- Radon is another gas that these monitors can test. It's a naturally occurring radioactive gas that can cause lung cancer. You can't see or smell radon so testing is the only way to know your level of exposure. If you live in an area where radon is known to exist, be sure to research and test your home.
What Can Clean the Air in My House?
You might assume your HVAC filter is cleaning the air in your house. It's filtering out some pollutants (read: How the Best HVAC Filters Can Save You Money) but it's primary goal is to protect the HVAC system.
Here are the decisions you'll need to make when picking your strategy for protecting indoor air quality in your home.
- Do you want an air filtration system for the entire house or just one or two rooms?
- Do you want to use an active or passive air purifying products?
Active air purifiers release negatively charged into the air. This causes pollutants to stick to surfaces rather than continue floating through the air. These active air purifiers include ionizers and ozone generators, and electrostatic filters. Ultraviolet(UV) lights
Passive air purification uses air filters to remove pollutants. Passive purifiers are more efficient as the pollutants are permanently removed from the air. which is why you need to change them every month or two. The filter's MERV rating, the higher the better, tells you how effective the filter is. HEPA filters are the most powerful but you need an HVAC system that supports HEPA filters. Activated carbon filters trap odors and gases.
Ultraviolet (UV) lights can also be installed in your HVAC system to purify air before it moves back into your house.
Here are more resources on protecting indoor air quality (IAQ):
- From the EPA, Air and Coronavirus (COVID-19)
- Consumer Product Safety Commission's Guide to Indoor Air Quality.
- Statistics on Air Pollution from OurWorldinData.org.
- EPA information about Indoor Particulate Matter.
- EPA information about Radon.