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If you recently tested your home for radon or saw news about higher radon levels in Pennsylvania and New Jersey, you might be wondering about what it means for your HVAC system.
Will it damage your expensive central air conditioner? Does it cause reduced furnace performance? Can MERV 13 filters trap it?
The answer is pretty straightforward. Radon gas doesn’t damage, corrode, or alter your HVAC system.
But HVAC has a massive impact on how radon moves through your home.
This guide covers how forced-air heating and cooling systems interact with soil gas in this region and what you can do to keep your family safe.
Pennsylvania ranks among the worst states for radon in the country, with an average level of 8.6 pCi/L. This is more than double the Environmental Protection Agency (EPA) threshold of 4 pCi/L. New Jersey also experiences significant risk from this gas.
Radon is found in the soil underneath your home foundation. It comes upward through foundation cracks and sump pits. Once it reaches the lowest level of your home, the HVAC system impacts how it moves throughout the home, lowers indoor air quality, and contributes to serious health hazards.
Here are the three major ways HVAC impacts radon movement in homes.
Most basements have exposed return air ducts. Or some have cracks and leaks that provide a pathway for soil gases. When the HVAC turns on, it acts as a vacuum and draws soil gases. This is a direct way HVAC contributes to radon inside.
Keep return air ducts fully sealed and insulated to prevent this effect.
In normal times, soil gases remain in close contact with the basement. But when your air conditioner or furnace runs, it mixes that settled air with the upward air. This effect mixes the unhealthy gases with the air inside where your family spends most of its time.
The solution lies in sealing the soil entry points, closing the duct leaks, and stopping the negative pressure in the basement.
If the system draws more air from lower levels than it returns, it creates a negative pressure in the basement. This suction effect pulls more radon upward.
Equalize the supply-to-return ratio and stop high-velocity suction near the floor slab.
HVAC air filters can’t trap radon, even if they are high MERV or HEPA filters. Still, HVAC can help in controlling radon.
Sealing joints in return ducts can prevent HVAC from drawing soil gases from lower levels. You can use mastic or foil tape for this purpose.
Installing an energy recovery ventilator ensures a fresh supply of outdoor air is maintained. This fresh air mixes with the inside air and dilutes radon levels. The strategy is especially good in homes with low to moderate radon levels.
For homes with radon above the EPA threshold of 4.0 pCi/L, installing an active soil depressurization system is essential. Make sure certified professionals install it and that HVAC works in coordination with it, rather than fighting against it.
Maintaining radon levels below the threshold requires the right strategy. Starting blindly might not yield desired results.
Here is the 4-step approach we recommend to our local homeowners.
Install a digital radon monitoring device at the lowest livable area in your home. If not possible, check current levels regularly with kit-based testing. It lets you set a baseline for effective management.
If you notice alarming values in step 1, the first thing to do is inspect return air ducts. And do it yourself; no need to hire a contractor. Notice all the areas with cracks, gaps, and fissures that you think could be pathways for soil gases.
Do it immediately. Allowing fresh air inside dilutes radon and minimizes health risks. Especially, keep some ventilation from the top rooms in your house instead of sealing them closely.
If results come back high after these steps, the culprit is likely very severe. This is the time to get in touch with an expert. Choose your local, licensed, and experienced professional who genuinely knows how to handle these issues.
For any kind of HVAC assistance, feel free to contact Lehigh HVAC.
