I did a random check on my sump pump pit( has a sealed lid) and when I popped the rubber plug out I was shocked to feel air coming out of the pit into my face. My house was a active radon mitigation system system that ties into the drain tile that goes into the sump pump pit. The first thing I did was to check the radon fan and yes it is pulling a vaccum. I don't ever recall feeling the air come out of the sump pump pit before but could be wrong. What do I have going on here? Any educated guesses? Nothing to worry about? Thanks in advance, I appreciate it.
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Sump pump pit and radon mitigation
- Thread starter mc1984ss
- Start date
steaks&anvils
Well-known member
WAG
is your sump dry? and the vacuum caused by the radon mitigation is "sucking" air in through the out sump let?
BUT it would have to get through the pump and I don't think that can happen?
or, if the radon is forcing air into the drain tile, then the sump is getting the air from that?
is your sump dry? and the vacuum caused by the radon mitigation is "sucking" air in through the out sump let?
BUT it would have to get through the pump and I don't think that can happen?
or, if the radon is forcing air into the drain tile, then the sump is getting the air from that?
jkeyser14
Well-known member
Make sure the radon fan isn't reversed?
jkeyser14
Well-known member
It can't be generating negative pressure relative to your room and yet still be shooting out air. It is impossible (physics).The sump pump pit is dry besides a couple drops of moisture. I had questioned the fan being reversed bit according to the gauge it is sucking. I wonder if barometric pressure had any effect on it?
APEowner
Well-known member
Is it possible that you were feeling air being sucked into the pit? Is the air coming from where ever the pump discharges to?
they told you it ties into the drain tile sure. but does it?It can't be generating negative pressure relative to your room and yet still be shooting out air. It is impossible (physics).
also you could still draft air in if it's being pulled out hard elsewhere. drop a smoke grenade down there and seal it again (for testing, not a grenade grenade), see where it comes out.
jimindm
Well-known member
I agree with the poster that mentioned physics.
Hold a candle near the pit and see what the air is actually doing.
We do not have a radon set up, but I have felt the same thing sort of when I lift the lid to our sump pump. Just have sort of figured it was the differences in temperature and the humidity of the air. What was sort of trapped under the slab and the conditioned air of the room the pit is in.
Basement is nice, cool, and air conditioned at this time of year. Lift the lid and some warmer air is introduced and it wants to rise.
Hold a candle near the pit and see what the air is actually doing.
We do not have a radon set up, but I have felt the same thing sort of when I lift the lid to our sump pump. Just have sort of figured it was the differences in temperature and the humidity of the air. What was sort of trapped under the slab and the conditioned air of the room the pit is in.
Basement is nice, cool, and air conditioned at this time of year. Lift the lid and some warmer air is introduced and it wants to rise.
larry4406
Well-known member
Areaway (basement exit external stairs) with drain? The drain usually is a home run to the sump crock without a pea trap to prevent freeze.
Hvac running while checking the crock? Return might be pulling air thru the drain and out the grommet hole.
On houses with areaway drains where we have had to install vacuum pump to activate radon system, we have added a 90 degree elbow inside the crock with a short piece of pipe so the pipe rim is below the standing water level. This ensures air does not come from the open drain and causes the vacuum pump to pull sub slab vacuum. Noticeable change on the manometer once the “snorkel” is installed; failing tests changed to passing once we figured out the air path bypass.
If your perimeter drain tile is daylighted, then you will have air leakage and minimal vacuum.
Hvac running while checking the crock? Return might be pulling air thru the drain and out the grommet hole.
On houses with areaway drains where we have had to install vacuum pump to activate radon system, we have added a 90 degree elbow inside the crock with a short piece of pipe so the pipe rim is below the standing water level. This ensures air does not come from the open drain and causes the vacuum pump to pull sub slab vacuum. Noticeable change on the manometer once the “snorkel” is installed; failing tests changed to passing once we figured out the air path bypass.
If your perimeter drain tile is daylighted, then you will have air leakage and minimal vacuum.
I definitely understand the physics of it that is why I was concerned and posted this, it just did not make sense. I was unable the check the mitigation exit tonight due to rain. I popped the plug out of the pit and the air movement was less noticeable than yesterday ( or so it seemed) using the smoke from a candle I was able to verify there was a slight suction into the pit which makes me happy.
The house does not have an area way and what you described makes sense. I will have to check it some day when the AC or furnace are running, what you mentioned about that also makes sense. The house is 6 years old and the mitigation pipe is tied into the drain tile with plastic under the entire slab.
The house does not have an area way and what you described makes sense. I will have to check it some day when the AC or furnace are running, what you mentioned about that also makes sense. The house is 6 years old and the mitigation pipe is tied into the drain tile with plastic under the entire slab.