Replies

1. 
   matthew25 | Feb 10, 2024 10:01am | #1

   Radon exhaust vents can go out the sidewall so long as you have no soffit or attic vents that could suck back in the radon into your attic. And since you have a conditioned unvented attic this should work. Same for plumbing vent pipes.

1. 
   AdamAtTrident | Feb 12, 2024 09:35am | #2

   With an active system, doesn't the fan usually have to be outside of living space? If true, that would make sidewall exhaust a bit difficult. Just trying to picture how that would work.

2. 
   DennisWood | Feb 13, 2024 12:27pm | #3

   You have a conditioned attic, which means the fan should not be located there. Any leaks on the high pressure side of the fan would end up creating very high radon levels in your living space...this is why the fans are located either outside, or in a vented attic space.

   1st floor/basement radon levels will generally be higher due to proximity to the foundation and levels will generally drop as you go up floors. The radon is typically coming from the ground underneath your home. Your flip flop may have something to do with ventilation in the home with no connection to water, or it may indeed be because of your well water. My guess though is that your pressure tank etc is in your basement? The EPA published a bit of data about this..and your well water radon level is far higher than their example: https://archive.epa.gov/water/archive/web/html/basicinformation-2.html#:~:text=Radon%20gas%20can%20also%20dissolve,and%20goes%20into%20the%20air.

   "Under the proposed regulation, States that choose not to develop enhanced indoor air programs, community water systems in that State will be required to reduce radon levels in drinking water to 300 pCi/L. This amount of radon in water contributes about 0.03 pCi/L of radon to the air in your home. Even if a State does not develop an enhanced indoor air program, water systems may choose to develop their own local indoor radon program and meet a radon standard for drinking water of 4,000 pCi/L."

   If the relationship is linear, then 5770 pCi/L in your water "should" account for an increase of 0.577 pCi/L in your home. If that is true, then spending money on well water mitigation may not be worth it if you have an ERV/HRV and a radon system lowering your house levels.

   Not sure why they are not exiting the sidewall, fan outside, and then exhausting above the roof line as you would typically see. Having the radon vent running up through the attic only really makes sense for very cold climates (where you want the vent pipes as warm as possible), not so much in southern Maine.

   As far as the well, no expert here, but if there is a bubbler in the well itself, then I would investigate venting the pump house/well enclosure away from your house, basically treating the water before it is inside the home. Assuming the well head is far enough away from the house, you could then just vent the well head enclosure with an exhaust fan. My folks house has a well with high sulphur, so runs a bubbler and pump that injects air about 100ft down into the well. No one has ever checked radon levels in the insulated well cap/cover enclosure, but it's likely very high.

1. 
   17whippoorwill | Feb 13, 2024 01:38pm | #4

   DennisWood, thanks for the info and advice.
   Forgot to mentin I 'do' have a Lifebreath ERV, and those measurements were with it in use.

   Air: the first radon contractor said they had to introduce outside air to the fan housing in the attic, so they would run another PVC pipe from the gable end into that fan housing. I was so annoyed with that requirement, I took them out of the running, but based on your advice, it would seem to be an important vent, considering my conditioned attic. I will ask the second contractor if they can locate the fan outside, and run it up the side of the house. It will not be visible from the road.

   Water: correct, water pressure tank in daylight basement mechanical room. cost for water mitigation range $5500 for inside units, to $6500 for unit at top of well. which also uses energy 'of a 90W light bulb' whatever that means.

3. 
   Collleen | Feb 13, 2024 02:08pm | #5

   New to GBA but did lots of radon research and mitigation many years ago. Were the radon in air results measured with sump basin dry, stubs open (unsealed) and the pvc pipe opened to top of house? If so, that is the reason you have higher results upstairs than basement ( that and possibly more leakage in your walk out basement than roof/walls). I recommend retest for shorter time period under closed house conditions with sump and pipes sealed. Your results may be much lower.
   Do not know Maine’s requirements but pipes inside are usually only needed for passive remediation to optimize stack effect. Active systems go out basement wall with pipe and fan as stated above.

4. 
   17whippoorwill | Apr 11, 2024 11:26am | #6

   Thanks for advice
   Follow up: Had preinstalled PVC pipe connected to sump, and RadonAway RP145c fan installed in conditioned attic ... radon level now under 1 pCi/L
   I see no need for radon in water mitigation, but will keep the Airthings monitor on all the time.