Condensation in radon system question

[Citation]

Once again I'm going to turn to this forum for a "not quite" garage question.

My house has a radon system with an issue with condensation. Since moving into this house I have to disassemble a part of my radon system perhaps once a week during the cold, wet months to drain condensation out of the pipes.

My system has a roughly horizontal run of around 14'. This run exits through a foundation/basement window of the original house foundation. It runs the 14' horizontally to a cinder block wall supporting an addition. There it exits and goes up the side of the house.

For what ever reason (bad workmanship?) there appears to be no slope to this 14' section. When I first moved in the system had a low point in the center of the span. That was likely due to a combination of water weight and no supports along most of that 14'. Last summer I shimmied under the addition and added a support so at least the pipe has a peak in the center. Now the condensation either runs back to the radon sump or out to the side of the house.


My question is how can I fix this?

To me, the most obvious fix is to move the exit of the radon pipe up the wall. That would allow the pipe to slope back to the radon sump over the full length. However this would require cutting a new hole in the exterior wall of the house and patching the old one.

Is there some type of inline drain option? I've seen some condensate drains that fit above the blower. I guess that is where most of the condensation occurs. such a thing would reduce how often I have to drain the condensation. Are there options that can go before the blower?

Thanks.

 

[stokefire7]

What does it look like ? Got any pics of the piping ?

 

[Kaizen]

Have you tried insulating it? Guessing your basement is warm but under slab temps are cold causing the condensation.


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[Showkey]

The water or condensing vapor returning to below the slab is normal. Water, back to the sump area or outside is acceptable.

Mine ( radon vent system) exhausted to through the roof. While it does exhaust water. The warm moist air condensed on exit and created a huge ice burg on the roof over time. Big enough to create an ice dam and roof leakin the garage. Purchased the home used....suspect this was a problem for years, but never addressed by the prior owner.

Moved the exhaust to horizontal through the wall. It now drips and creates an ice sculpture below the pipe on the ground. It been this way for 5 years now........

Obviously it’s only an issue during very cold weather.

In the summer the pipe through the garage may sweat as the pipe is cool and the garage air maybe be warm and moist. Not a big problem, nature of the beast, conditions have to just right. The pipe in the basement does not sweat as the basement air is conditioned and dehumidified.

Agree radon abatement contractors work can be marginal to piss poor.

 

[larry4406]

Not much help here, but on our new construction homes, we run a dedicated 3" PVC line from the basement sump crock via sealed lid thru the roof, with typical roof boot. Normal minimum 1/4" per foot slope if not vertical.

Any condensation that would form, drains to the sump where it mixes with any groundwater and is pumped away by the sump pump.

 

[Citation]

It's hard to get a picture of the system but here is a sketch. The blower and vertical run of the system are outside the house. The horizonal is inside of an insulated crawl space. The swell in the center of the horizontal pipe is perhaps exaggerated but it's there. I don't have ice issues that I've ever seen but that's likely because most of the water is in the horizontal section. If I don't drain it it eventually stops things up.

 

[jkeyser14]

Can you lower the end at the basement wall/sump pit to get the needed slope?

 

[stokefire7]

I wonder if your blower has fallen a little bit. You'll have to do the math , developed length minus what ever fall you want. It would work with as little as 1/8" per foot.
If you have that, it's just a matter of supporting it , if not , you'll have to cut a section out and recouple it and support.

 

[CraigStu]

looks like you either raise the outer wall hole or lower the inner wall hole. I don't see much choice to be legal. Maybe a 1/4 inch hole at the low point of the pipe would work out but the radon police won't like it.

 

[Citation]

Can you lower the end at the basement wall/sump pit to get the needed slope?

Not easily. I'm not sure what all I'm up agaist but it will involve going through the old foundation wall. The installers (before my time) elected to go through an existing window opening. On the exterior wall I can go up perhaps the height of a row of cinder blocks. That isn't a huge slope but it would result in a slope down towards the slap. It's just that involves cutting a new hole with tools I don't own. Not that a lack of tool ownership is ever an excuse around here...

Still, if there is some type of in line drain system I would probably rather do that then making new holes in foundation walls.

 

[Citation]

I wonder if your blower has fallen a little bit. You'll have to do the math , developed length minus what ever fall you want. It would work with as little as 1/8" per foot.
If you have that, it's just a matter of supporting it , if not , you'll have to cut a section out and recouple it and support.

The blower appears to be where it was first installed. It's just an elbow after where it goes through a cinderblock wall. Not likely to have slipped. I suspect when the system was first installed the PVC was close enough to horizontal that no one thought a thing about condensation. The fact that they had perhaps 10' of unsupported pipe says someone wasn't thinking. Ultimately I think this was a lazy/poor installation job done decades after the house was built. It's hard to get into the crawl space so it would be hard for an inspector (if one was ever called) to verify the slope. Yet another reason why I don't like buying houses that should have been someone else's project. But my wife loves the "character".

 

[yeldogt]

What size blower -- have you had the house checked for radon?

It's not uncommon for the systems to depressurize the basement and draw in warm air that pick up moisture ... sometimes the blower is too larger or there are leaks in the system.

It seems the sump pump often is an easy work around when doing them new --

Think you are going to have to lower the inner wall ... I wonder how much stone is under the slab

 

[White Shadow]

I'd just seal it off completely. Radon mitigation is a complete scam. It's just a money grab that's perpetuated on scare tactics.

If you really research it, you'll understand why nobody should worry about radon in their house/basement.