OT: Testing for radon gas in your home

[Louis]

Originally Posted by Jaybee

The standard 48 hour test isn’t a long enough period to capture natural fluctuations in the subsurface. Test a few times if you live in a high-risk area.

In my experience radon levels are hugely influenced by the weather outside.

The folks who tested my house before I bought it showed me the time-history plot of the levels over time and there was a big increase when a storm system came through.

Here's one explanation:

http://www.lifetimeradon.com/GasRemo...-Radon-Testing

[NHAero]

You both might also look carefully at whatever the mounting hardware is that holds the pipe. Putting a piece of hard rubber in between the base of the hardware and the building might help. We've had similar issues with wall-mounted hardware for minisplit heat pumps.

Originally Posted by C40_guy

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.

[Spaghetti Legs]

Originally Posted by NHAero

You both might also look carefully at whatever the mounting hardware is that holds the pipe. Putting a piece of hard rubber in between the base of the hardware and the building might help. We've had similar issues with wall-mounted hardware for minisplit heat pumps.

Good ideas, thanks to both of you. C40_Guy, here’s a gratuitous pic from yesterday’s ride on my C40

[C40_guy]

Originally Posted by Spaghetti Legs

Good ideas, thanks to both of you. C40_Guy, here’s a gratuitous pic from yesterday’s ride on my C40

Sweet!

I will probably be getting my C50 out this weekend, for its first ride of the year...and its first ride since over a year ago.

My C40 was retired and sold about 8 years ago... I need to finish building my Master and Prestige, and get the bikes those replaced sold!

[C40_guy]

Originally Posted by NHAero

You both might also look carefully at whatever the mounting hardware is that holds the pipe. Putting a piece of hard rubber in between the base of the hardware and the building might help. We've had similar issues with wall-mounted hardware for minisplit heat pumps.

I think my fan is already somewhat isolated, but I'm not sure. I'll take a look. It's a good idea!

[mdeth1313]

Originally Posted by oldpotatoe

Son did and they then set up a continuously running vent that moves RADON to outside. If it's high enough, you shouldn't just monitor but remove. It was part of his pre-buy inspection so paid for by the seller.

This - found during inspection so the seller had to remediate. Best part was they wanted to give us a certain amount of money and let us deal with it AFTER it was sold. Naturally, we refused. Their radon problem could have become our radon problem. Fortunately, the system worked perfectly and is still going strong.

[saf-t]

Originally Posted by NHAero

TL;DR warning!

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.

Same principle applies to virtually all exhaust ventilation for contaminant control- you never want the bad stuff to be forced out of a leaking duct into an occupied space. Sucking clean air into a leaky duct is no problem.

[OtayBW]

Originally Posted by 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.

Radon is thought to be retained by physisorption, ideally on high surface area adsorbents such as silica gel or activated carbon. Your sand aquifer and overburden material may be good for filtration of residential/municipal sewage and etc., but possibly not so good (too coarse crystalline) for adsorbing/immobilizing radium or uranium isotopes....
Just spitballing...

[jamesdak]

Originally Posted by oldpotatoe

Son did and they then set up a continuously running vent that moves RADON to outside. If it's high enough, you shouldn't just monitor but remove. It was part of his pre-buy inspection so paid for by the seller.

Yep, this is basically what I had installed in my current home. Been running 15 years trouble free.

[C40_guy]

Originally Posted by mdeth1313

This - found during inspection so the seller had to remediate. Best part was they wanted to give us a certain amount of money and let us deal with it AFTER it was sold. Naturally, we refused. Their radon problem could have become our radon problem. Fortunately, the system worked perfectly and is still going strong.

We did it the other way round. I wanted to be able to select the installer and the approach.

[NHAero]

Agree. I got $1500 off the purchase price, and someday will install a system.

Originally Posted by C40_guy

We did it the other way round. I wanted to be able to select the installer and the approach.

[zap]

edit

Originally Posted by Louis

In my experience radon levels are hugely influenced by the weather outside.

I was told that winter time when the ground is frozen is best to capture peak radon levels. This is also when many of us are in the pain cave breathing viciously hard.

[NHAero]

I think you're right - certainly no resistance to gas flow.

Originally Posted by OtayBW

Radon is thought to be retained by physisorption, ideally on high surface area adsorbents such as silica gel or activated carbon. Your sand aquifer and overburden material may be good for filtration of residential/municipal sewage and etc., but possibly not so good (too coarse crystalline) for adsorbing/immobilizing radium or uranium isotopes....
Just spitballing...

[Kyle h]

My wife and I bought our home as a cash quick sale, knowing it was basically going to need an entire guy and redo and thus didn’t have a typical inspection done prior.

Because of this thread I bought a RadonEye sensor and plugged it in this week. Granted it’s been cold this past week but our numbers are scary. Averaging 5.2 with spike as high as 6.3. Our workout room is in the basement and now I’m actually a bit bothered by overlooking this. Many thanks to everyone here posting.

[echappist]

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