Radon Fan Experience & Recommendation

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Gd_Enf_56
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Radon Fan Experience & Recommendation

Post by Gd_Enf_56 »

Live in 1-story SFH with mostly finished basement. Purchased this "forever home" in 2017 and enjoy it. It has a sump pit with pump and vent piping that extends upward to the attic and thru the roof.

Current readings from Airthings monitors (in basement) show:
a) 1.97 - finished bedroom
b) 2.35 - finished media room
c) 2.37 - unfinished section near sump pit

Thinking of getting a radon fan installed on the attic vent pipe.

Any recommendations on "quiet radon fans"?
PaunchyPirate
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Re: Radon Fan Experience & Recommendation

Post by PaunchyPirate »

I'm a little uncertain about your current configuration. Is the basement floor already set up with the proper pipe(s) into the sub-concrete surface for radon mitigation? I'm not familiar with how this works when sump pumps are in the equation. Is it the same vent piping used for both?

I don't know the brand of attic vent fan that was installed in my previous home, but I never had a clue there was a fan up there. Never heard a thing.
Topic Author
Gd_Enf_56
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Re: Radon Fan Experience & Recommendation

Post by Gd_Enf_56 »

There are 2 pipes coming out of the sump pit. One is for ejecting the water that accumulates from the a/c line and drainage tiles. The other is the vent pipe.

From what I'm gathering, a radon fan connected to the vent piping in the attic helps reduce the radon levels in the basement.

Good to know the radon fan in your home is not detectable as far as the sound goes.
chassis
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Re: Radon Fan Experience & Recommendation

Post by chassis »

Attic location for fan. Choose a location in the attic farthest from your bedroom. Can’t hear it.
InvisibleAerobar
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Re: Radon Fan Experience & Recommendation

Post by InvisibleAerobar »

Gd_Enf_56 wrote: Mon Feb 03, 2025 2:32 pm Live in 1-story SFH with mostly finished basement. Purchased this "forever home" in 2017 and enjoy it. It has a sump pit with pump and vent piping that extends upward to the attic and thru the roof.

Current readings from Airthings monitors (in basement) show:
a) 1.97 - finished bedroom
b) 2.35 - finished media room
c) 2.37 - unfinished section near sump pit

Thinking of getting a radon fan installed on the attic vent pipe.

Any recommendations on "quiet radon fans"?
Both Radon Away and Festa Eagle are well-regarded.

In terms of noise, a larger diameter pipe (upgrading from 3" to 4") helps.

We had such a set-up (regular fan but with upsized pipes). Fan was located right outside and directly below our bedroom window, and I never noticed any noise during use.

In another set-up, we used a slightly more powerful fan located at a comparable distance, and that thing was like a white noise machine.
Topic Author
Gd_Enf_56
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Joined: Wed Apr 02, 2014 7:10 am

Re: Radon Fan Experience & Recommendation

Post by Gd_Enf_56 »

InvisibleAerobar, thanks for the info on the models. The vent piping I have is 3" pipe.

With regard to your comment about upgrading to a 4" pipe, do you mean
a) on the end/stack portion that goes thru the roof?
Or
b) upgrade the entire length of the vent pipe from the sump pit thru the roof?
Saving$
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Re: Radon Fan Experience & Recommendation

Post by Saving$ »

If your sump pit cover is not a sealed cover, first get a sealed cover
- It may lower your radon readings sufficiently
- You need a sealed cover to run a radon fan; otherwise the fan just removes air from the basement, and you want it to remove subslab air

When looking for a fan, there are several factors
- each fan is rated for airflow, measured in cfm (cubic feet per minute). The airflow capacity you need is based on your radon readings. Some have various speed settings so you can adjust for the specific install
- Radon fans are rated by efficacy - how many cfm they remove per watt of electricity used. There is a wide range.
- Some fans also have a sone (sound) rating.
- Installing with flexible couplings at the fan (they look like a fernco but are specific for radon fan install) will greatly reduce vibration and thus perceived noise, rather than installing with hard pipe fittings
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lthenderson
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Re: Radon Fan Experience & Recommendation

Post by lthenderson »

In a previous home, the fan was installed outside the conditioned envelope and you couldn't hear it at all. More specific to our case, it was outside the house and the only time I knew it was running was when I was within maybe 10 feet of it on the outside of the house and then it was just a hum.

Like already mentioned, I've never had one in conjunction with the sump pit but I would think that you need a well sealed lid on the sump pit (assuming sump pit is inside your conditioned envelope) to be effective and to not exhaust all your conditioned house air and create a vacuum effect inside. Ours had it's own separate pit with an air tight lid that was never opened.
InvisibleAerobar
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Re: Radon Fan Experience & Recommendation

Post by InvisibleAerobar »

Gd_Enf_56 wrote: Mon Feb 03, 2025 3:11 pm InvisibleAerobar, thanks for the info on the models. The vent piping I have is 3" pipe.

With regard to your comment about upgrading to a 4" pipe, do you mean
a) on the end/stack portion that goes thru the roof?
Or
b) upgrade the entire length of the vent pipe from the sump pit thru the roof?
I don't recall right now (the one I mentioned is at a previous residence), but I should be speaking with the same contractor in a few weeks and can find out. If my recollection is correct, it's at least the length from the sump pit to the fan.

One thing to pay attention to is the static pressure drop (measured in in. of H2O). There's an inverse relationship between CFM moved vs static pressure drop, and ultimately as another forumite mentioned, it's the CFM moved that mitigate things.

Your set-up sounds like you have drain tiles around the perimeter and a sump pump. In general, this gives quite a lot of area for air to be moved, which bodes well for the efficacy of your system. That your reading is ~2 pCi/L before mitigation also bodes well. In my previous residence (with a partial drain tile + sump), the reading in the basement was 10 - 30 pCi/L prior to mitigation, but it dropped to sub 0.5 pCi/L afterwards.

Radon Away and Festa also have literature on their fans. For instance, here's Radon Away's page on one of its fans, and here's the installation instruction for this fan. Each of the companies make a series of fans, and some should be on the quieter side. I'd think you can actually seek out the quieter fans these companies offer.

Much harder is when the material under the basement is really dense and there is no drain tiles, which makes it really difficult to move air. Those situations limit fan selection.
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