Radon mitigation with ERV or other, HELP!
We moved into a house 8 years ago with a new radon mitigation system installed. The house had been added onto 2 times with several different footers/foundations. Recently, we got an Airthings Wave and after a week in 3 different locations (basement and 2 areas on main floor) the radon average is 8.3 pCi/L with a peak of 11 pCi/L. This was all recorded with the radon mitigation on. Not trying to disparage the radon installers, but I’ve talked with a few and they don’t instill confidence.
So, on to the question. What would be the best way to mitigate the radon? The basement is all cement with 6 rooms. All drop ceiling and a 5 foot high cemented crawlspace. I have a commercial dehumidifier in the crawl space aleady. I’ve been thinking ERV with ducting to some the areas.
The suggestion from radon people was to install more pipes in concrete and more pumps.
I live in Lancaster PA. So mid Atlantic climate, and with global warming it’s been pretty mild in winter lately.
Thanks so much!
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If you do research on radon, I believe you will learn that one of the important factors in Radon control strategy is sealing. If you have a sump pump, if you have cracks or gaps in the basement concrete slab or the gaps/holes in the plastic crawl space liner, etc they all contribute significantly to radon.
It might be worth your time to seal things like crazy.
Also make sure your radon fan is actually work and exhausting underslab air...
Yeah I'm not an expert but I also have to wonder if something is wrong with the sealing and if you are pulling radon into your house (through your use of bathroom fans, stove fan, etc.) Think about all penetrations in your basement walls and floors (where does your water line come in, etc.) Do you have any plumbing/bathrooms in the basement? Are the walls poured concrete or cinder block?
Interestingly, you might find that while sealing the basement up more effectively, you need to make it easier for air to get into your house upstairs so that your bathroom fan, etc. isn't creating significant negative pressure. In the short term, you can test that by just cracking open a window when you are using any exhaust fans upstairs.
I also agree that it would be a good idea to do a quick diagnostic on your existing system. Is it actually exhausting air? Is it sealed up properly?
RE an ERV: You might be able to do some cheap tests before committing to it. E.g. Cracking open a basement window and running a fan. It is not a long term solution (would use too much energy) but if you can gain confidence that a certain level of ventilation will fix your problem, then you can proceed more confidently to size the ERV correctly.