OT: Testing for radon gas in your home

[echappist]

Originally Posted by rwsaunders

Good info...PA’s site has informative videos as well.

https://www.epa.gov/radon/epa-map-radon-zones

https://www.dep.pa.gov/Business/Radi...-the-home.aspx

https://www.dhs.wisconsin.gov/radon/infocenters.htm

Originally Posted by ORMojo

Yes, from State of Oregon

Here is Wisconsin's. Interactive map, so you can play with it for your locale.
Attachment 1697998610

Unfortunately, it looks like your area has a relatively high likelihood of high concentrations of radon.
Attachment 1697998612

Thank you both; that was very helpful

I think I'll go buy one of those Radon Eye RD 200 units mentioned upthread. Was going to pick up a kit from the county, and have it run while we were away for a few days in March. Obviously, the pandemic changed things.

This thread is a very timely reminder, and thanks to all for the much needed PSA.

[C40_guy]

Originally Posted by echappist

Thank you both; that was very helpful

I think I'll go buy one of those Radon Eye RD 200 units mentioned upthread. Was going to pick up a kit from the county, and have it run while we were away for a few days in March. Obviously, the pandemic changed things.

This thread is a very timely reminder, and thanks to all for the much needed PSA.

Looks interesting. Post a review after you've run it for a while.

Some good reviews on Amazon, btw...

[OtayBW]

Al these hot spots should be closely associated with igneous, or igneous-derived) metamorphic rock, fwiw.

[binouye]

Originally Posted by Veloo

I'm considering these two models:

Airthings Corentium
https://www.airthings.com/en-ca/home

A friend who works for the State health dept recommended that one, having compared it to the professional units costing several thousand$$. So I bought one, it was super easy to set up and use, and gives both 48hr and 7day moving averages. Fortunately our house's radon values are low enough we don't need to do any mitigation.

[rockdude]

Years ago, I research Radon and wanted to know what the science and research said about death/cancer rate for home owner at different concentration levels. I didn't find anything. Most of the research was done in Mines with very high levels from 70 years ago. Has anyone seen any real research on homes and the actual cancer rates back by radon levels and exposure time? My questions is, what is the real risk that has been validated by science?

[C40_guy]

Originally Posted by rockdude

Years ago, I research Radon and wanted to know what the science and research said about death/cancer rate for home owner at different concentration levels. I didn't find anything. Most of the research was done in Mines with very high levels from 70 years ago. Has anyone seen any real research on homes and the actual cancer rates back by radon levels and exposure time? My questions is, what is the real risk that has been validated by science?

@rockdude Here's a pretty detailed discussion of the question you raise.

Take a look and let us know if you think the studies have identified a causal relationship.

[OtayBW]

Originally Posted by rockdude

Years ago, I research Radon and wanted to know what the science and research said about death/cancer rate for home owner at different concentration levels. I didn't find anything. Most of the research was done in Mines with very high levels from 70 years ago. Has anyone seen any real research on homes and the actual cancer rates back by radon levels and exposure time? My questions is, what is the real risk that has been validated by science?

May or may not be what you're looking for, but here's a relatively recent link that may help. The references may be helpful. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6211050/

[NHAero]

As I wrote above, we've used these for a couple of years and validated against a professional grade instrument.

Originally Posted by C40_guy

Looks interesting. Post a review after you've run it for a while.

Some good reviews on Amazon, btw...

[NHAero]

TL;DR warning!

As a building engineer, I have colleagues throughout North America, including some of the most prominent indoor air quality experts. I'd say that there isn't 100% consensus - I have one very respected colleague who is a contrarian about radon being as big of an issue as it is made out to be - but there's a pretty high consensus that it is a real issue.

That said - my field includes very low energy use buildings, which are very airtight, with mechanical ventilation, which is why I've been interested in radon. Soil gases entry into buildings depends on the pressure gradient and direction - mitigation systems depressurize the building sub-slab. I've noticed that in houses of normal air tightness, radon levels can be very roughly correlated with the weather. As one of my clients said, after we looked at the data from his house, the radon level shoots up when the ferries are cancelled (really windy days, Martha's Vineyard). Interesting to me is the fact that I know the air change rate in this house is higher on those days, from wind pressure, but that whatever the radon transport driver is, it's stronger than air change rate. This has been validated in general terms, both for radon and other pollutants - source strength is more important than air exchange rate.

Another observation that relates to house air tightness. In typical houses here in the northeast, if the radon level in the basement is X, it's common for the radon level on the first floor to be +/- half of X. In really tight houses, the level on the first floor tends to be much less than the basement level. At my house (140 CFM50 for blower door afficianados) my bedroom on the first floor is 8 to 10 times lower than the basement radon level. I don't spend much time in the basement - I do work on bikes down there, that's about it - so I haven't installed a mitigation system. I know that it's likely I'll install one when I go to sell the house. The reason I put it off is that I want the house to be balanced in terms of pressure, because I have a wood stove that i don't want to backdraft. Radon mitigation fans tend to run houses negative relative to outdoors, and the tighter the house, the more negative.

Current guidelines include placing the fan outside the pressure boundary of the house. If you have an unconditioned attic, that's a good place for the fan. The reason is that any leaks on the downstream, pressure side of the fan bring concentrated radon into the house! If the house is all cathedral ceiling with no attic, the fan ends up outdoors.

Originally Posted by rockdude

Years ago, I research Radon and wanted to know what the science and research said about death/cancer rate for home owner at different concentration levels. I didn't find anything. Most of the research was done in Mines with very high levels from 70 years ago. Has anyone seen any real research on homes and the actual cancer rates back by radon levels and exposure time? My questions is, what is the real risk that has been validated by science?

[NHAero]

True. What's interesting to me, having moved ten years ago to Martha's Vineyard, is that the rock is pretty far down here (my well is in a sand aquifer where the water level is over 70 feet down) and yet there is still plenty of radon.

My conclusion is that experts still don't understand the mechanisms that cause the fluctuations in radon levels in buildings. I monitored hourly radon levels, pressure between the basement and outdoors, and outdoor temperature, and plotting them all it seemed that temperature was a closer curve than pressure - which is not intuitive at all.

Originally Posted by OtayBW

Al these hot spots should be closely associated with igneous, or igneous-derived) metamorphic rock, fwiw.

[ORMojo]

Originally Posted by NHAero

TL;DR warning!

All this talk about "airtight" and "gases" and "air exchange rate" and much more will forever make me associate your NHAero user name with different impressions than previously!

[echappist]

Originally Posted by NHAero

TL;DR warning!

As a building engineer, I have colleagues throughout North America, including some of the most prominent indoor air quality experts. I'd say that there isn't 100% consensus - I have one very respected colleague who is a contrarian about radon being as big of an issue as it is made out to be - but there's a pretty high consensus that it is a real issue.

That said - my field includes very low energy use buildings, which are very airtight, with mechanical ventilation, which is why I've been interested in radon. Soil gases entry into buildings depends on the pressure gradient and direction - mitigation systems depressurize the building sub-slab. I've noticed that in houses of normal air tightness, radon levels can be very roughly correlated with the weather. As one of my clients said, after we looked at the data from his house, the radon level shoots up when the ferries are cancelled (really windy days, Martha's Vineyard). Interesting to me is the fact that I know the air change rate in this house is higher on those days, from wind pressure, but that whatever the radon transport driver is, it's stronger than air change rate. This has been validated in general terms, both for radon and other pollutants - source strength is more important than air exchange rate.

Another observation that relates to house air tightness. In typical houses here in the northeast, if the radon level in the basement is X, it's common for the radon level on the first floor to be +/- half of X. In really tight houses, the level on the first floor tends to be much less than the basement level. At my house (140 CFM50 for blower door afficianados) my bedroom on the first floor is 8 to 10 times lower than the basement radon level. I don't spend much time in the basement - I do work on bikes down there, that's about it - so I haven't installed a mitigation system. I know that it's likely I'll install one when I go to sell the house. The reason I put it off is that I want the house to be balanced in terms of pressure, because I have a wood stove that i don't want to backdraft. Radon mitigation fans tend to run houses negative relative to outdoors, and the tighter the house, the more negative.

Current guidelines include placing the fan outside the pressure boundary of the house. If you have an unconditioned attic, that's a good place for the fan. The reason is that any leaks on the downstream, pressure side of the fan bring concentrated radon into the house! If the house is all cathedral ceiling with no attic, the fan ends up outdoors.

Thanks for taking the time to share your insight

[C40_guy]

Originally Posted by NHAero

TL;DR warning!


I know that it's likely I'll install one when I go to sell the house. The reason I put it off is that I want the house to be balanced in terms of pressure, because I have a wood stove that i don't want to backdraft. Radon mitigation fans tend to run houses negative relative to outdoors, and the tighter the house, the more negative.

Interesting. Ideally the slab is fully sealed except for the radon pipe penetration, so there shouldn't be *much* air pulled down through the slab and then out, right?

Otherwise, you'd risk poor performance from an oil or NG heating appliance that's typically located on the same level.

If your woodstove is on the first level, you will probably get plenty of make up air from the usual sources...if not you could always install an OAK.

Our house is pretty tight...I'm not sure what our CFM test showed after topsealing in the attic and some other minor steps. If I'm not careful when I first light our woodstove (insert) I can get a cold, smoky downdraft. Cracking a window helps. Once the fire is established I get a good clean burn, which means the stove is getting enough air from somewhere. I think for the stove its the cold flue creating the downdraft rather than the stove being starved for air.

Gas cooktop and clothe dryer operate normally. We also have an HRV for the first floor...the people doing the insulating work, (partially underwritten by Mass-Save), required that.

I might pick up one of those electronic radon monitors to see if woodstove (or boiler use) pulls air through the slab.

[Spaghetti Legs]

Good discussion. We've had radon testing done at all of home sales and purchases over the years. It's never been much of an issue until our current house where the level was 12. Seller installed a mitigation system like that pictured by Old P and levels remeasured I believe < 1.

One point of consideration if you're going to get a mitigation system: Mine has an exhaust fan on the outside of the house just above ground level. It's pretty quiet to stand next to it but the sound transmits up the exhaust pipe which runs next to our bedroom window so there's a constant hum which is kind of annoying. I've thought about running it intermittently such as turning it off (has it's own breaker) at night. I don't think it would have that much effect on radon levels but might shorten the life of the fan as I hear it's better to just let them fun 24/7. Point being, if you're getting a system, run the piping somewhere you don't plan on extended sitting quiet time.

[C40_guy]

Originally Posted by Spaghetti Legs

One point of consideration if you're going to get a mitigation system: Mine has an exhaust fan on the outside of the house just above ground level. It's pretty quiet to stand next to it but the sound transmits up the exhaust pipe which runs next to our bedroom window so there's a constant hum which is kind of annoying. I've thought about running it intermittently such as turning it off (has it's own breaker) at night. I don't think it would have that much effect on radon levels but might shorten the life of the fan as I hear it's better to just let them fun 24/7. Point being, if you're getting a system, run the piping somewhere you don't plan on extended sitting quiet time.

As mentioned above, our system was run internally and the fan is in an unconditioned space next to our bedroom. We have a similar issue with the hum...it's quiet, but it's there. My short term solution was to wrap some insulation around the fan and pipe, which reduced the noise transmission somewhat.

My next step is to apply some DynaMat to the pipe, to further dampen the vibration. I haven't gotten to it yet as the insulation cut most of the noise, and I don't happen to have enough DynaMat on hand to really do the job. (What I have is left over from an automotive interior swap). DynaMat might be a better solution for you too, given the outside location of your fan.