RadonAway 23005-1 GP501 Radon Mitigation Fan, 3" White

After charcoal test-kit testing my 20yr home for radon and finding 9.6 pCi/L in the basement, I ordered two more of the test kits for confirmation. The repeat test in the basement came back at 19.8 pCi/L. I needed to do something, but wasn't about to spend a couple $k to hire someone and decided to do the work myself. I ordered the RadonAway GP201 and purchased other supplies. Not wanting to continue mailing out test kits, I purchased the Corentium 223 radon monitor to do continuous radon testing. My basement has 10" thick concrete block walls and a pored concrete floor over a polyethylene vapor barrier over 8" of 3/4" stone. I rented a 4" hole saw for 4 hours and drilled through my concrete floor. Then ~5gal of stones were shop-vacuumed from under the hole. The system was assembled and powered through the Fantech WC 15 speed control. I added the speed control when I learned that the GP 201 can be power by a solid state speed control. My concern was that maybe the GP 201 was too large a fan for my needs. The startup setting of the speed control was set to maximum with a fan vacuum of 0.41", and the radon reading was 18.6 pCi/L. One day latter, the radon reading was ~1.2 pCi/L. The speed control was then set to 1/2 speed, the next day the radon reading was less than 1 pCi/L. I then set the fan speed controller to minimum. The fan vacuum read 0.20" and the radon reached a stable 0.89 pCi/L the next day. It has been holding lower than that level for the last 3 days.It appears that I oversized the fan needed for my radon removal needs, but I'm still happy for the purchase of the GP 201. The GP 201 is quiet and I found using the mounting plate on the fan very useful for a secure mounting. Running the GP 201 at low speed using the speed control will minimize the electricity used.I now have something you may find very interesting, the noise power created by the GP 201. It seems that most fan manufacturers don't post noise values for their radon fans. It turns out that I have a sound power measuring device and took some noise measurement of my fan from a distance of 1ft from the fan for different speed control settings. The results:Fan off - 43.2 dBMinimum speed - 52.8 dBHalf speed - 53.9 dBMaximum speed - 57.6 dBAs can be seen, the GP 201 is a very quiet fan. It can't be heard outside the area of the fan location.

Before the fan, I had a radon reading that fluctuated between 2.8 and 4.3. Now with the fan, it's reading between 0.8 and 1.1. I had several challenges given my home size and structure, so this is what I had to do: My house had a passive pipe stacking the middle of the house going up 3 stories to terminate in the attic (so there was a long pipe stretch to suck through and due to finish spaces, several tight pipe turns that I feared would reduce effectiveness). I have a large home with basement footprint about 2000 sqft with 3 main, mostly isolated sections under the slab due to the way the footers are situated (I have the house plans). So I feared at best I would need multiple suction points, or at worst multiple fans, but I started with the single GP501 fan and the passive pipe I already had. I cut the bottom of the pipe and slab, and dug out 10 gallons of sub slab material which is a combo of approximately 2-4 inches of gravel on top of pure clay (before that the pipe just terminated in the ground with no air pocket). I tried to seal some cracks and seams in the basement slab, but since it's partially finished, I could only do that for about half the floor space. I installed the fan in the attic and had my roofer extend the pipe through the roof at close to the highest point of the roof ridge as possible without it being visible from the front of the house. The results are better than I expected! I have two continuous radon detectors in the basement in different locations and one is now reading 0.8 after 14 days pretty consistently, and the other is 1.1. I will say, the fan is not that quiet, and I can hear it in the room where it is above (although it is a low hum that is easy to ignore). I have a tall house, and can even hear it outside a little bit, but just a quiet low hum from the pipe. But I would trade that sound any day for the suction and results this fan provided!

GP501Bought this to replace HP401 that started making sounds. It’s a direct replacement, according to my radon guy.Of course, my fan stopped making noise once the new fan arrived. Because I got it for a good price ($212) and the old fan is likely on its way out, I decided to keep it.It does seem to be the same size, and has identical connections. Will update the review once installed.

Bought this thing a few years back and it’s still running quietly.

I can't say like others that this is entirely quiet...I have it installed in my garage and there's no need for a visual indicator for whether it's on or not. It's obviously on. The wall it's attached to is on the other side of my kitchen inside the house, and honestly you can hear/feel the hum of its operation if you listen for it. With that in-mind, it's a powerful fan. After hooking it up and the whole 9 yards I needed to put on a PermaBoot due to the rubber on the existing flashing having corroded away essentially...while on the roof the amount of air this fan pushes is impressive.That being said, I had a pre-install radon level(short term) measured at ~12 - and after install it dropped to ~1-1.5 within about 2 or 3 days. After installing a sealed Radon Sump Dome my levels have dropped even more. All measurements were done from the sump pit closet.[Update 05/18/2017]My radon levels have continued to go down, and now are sitting pretty consistently at a .5 for short and long term readings. I'll be capping my sump pit after I finish plumbing in my battery backup, and see if it gets even lower - but at that level it's basically at the national average of ambient outdoor radon levels. It made it through our Wisconsin winter without any obvious problems - temps dipped down into the -20F to -30F ranges, some heavy snowfalls, etc. Seemed to power through it just fine.