It thins radon out
Outdoor air comes in and mixes with the air inside.
Can an HRV lower your radon?
A balanced HRV that runs all the time and is kept up can lower radon by about 20 to 50%. That's less than a radon system, so it may not be enough for a high result.
One that pushes out more air than it brings in can pull more radon into the house. Whatever you change, test again to see what it did. (source) (opens in a new tab)
20% to 50%
Radon cut from a balanced HRV, run continuously
90% or more
Cut from a full radon mitigation system
200 Bq/m³
Health Canada (opens in a new tab)'s guideline. Above it, fix it.
At least 91 days
A long-term test, run after any change
What is an HRV?
HRV stands for heat recovery ventilator. An ERV (energy recovery ventilator) works much the same way. Health Canada (opens in a new tab) counts both as balanced ventilation: fresh air comes in, stale air goes out, and radon goes out with it.
How can an HRV change your radon level?
It has to be balanced
A fan that only pushes air out lowers the pressure in the house, and that can draw more radon in.
It only works while it runs
Health Canada (opens in a new tab) says ventilation needs to run all the time. Turn it down or off and radon climbs back.
- 1Fresh air in.
- 2The HRV. Balanced, it moves about as much air in as out.
- 3Stale air out.
When might an HRV be enough?
Health Canada's guideline is 200 Bq/m³. If your result is only a little over it, and the HRV runs all the time and is kept up, a 20 to 50% cut might bring it under. The only way to know is to test after.
What works better for a high result?
A radon mitigation system. It pulls the gas from under the floor and vents it outside before it gets in. Health Canada calls this method (active soil depressurization) "the most trusted and effective solution", at 90% or more. See how a radon system works and what it costs.
Got a high result? See what to do nextWe don't work on HRVs.
How do you know if your HRV helped?
Test again with a long-term test after any change. That's at least 91 days. Our guide to short and long tests explains why.
Run the HRV the way you normally do while the test runs. Health Canada says not to change how you live during a long-term test.
Want a retest? See your testing options.
Book a test or ask for a quote
Tell us about your home and your result, if you have one.
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