Bathroom vent fan dripping water
#11
  Re: (...)
So there I was lying in bed last week fighting off Strep throat infection and my wife tells me there is water dripping from the vent in the bathroom after she took a shower.

"Sure...probably just a little condensation...let me sleep". Then I hear drip, drip, drip, drip, drip.......about that fast. I guess it just pulled too much moisture up there and the extra cold temps really made it condense in the pipe. I have already suggested just leaving the fan off and the door cracked between the bathroom and bedroom when showering in the winter...which is it we are trying to remove from our house when it is 9 degrees out...the heat or the humidity? Now this is a 3rd reason to not turn on the fan and leave the door open enough to let the steam out.

FF to this week. It starts dripping after I get out of the shower when the fan has not been on. I keep the door shut while showering to keep the noise down since I am the first one up, then crack it a little when I get out to let the moisture out.

I'd say it probably dripped out 2 TBS of water in less than 2 minutes. I turned on the fan to pull air through and it stopped pretty quickly.

Is this just heat rises and the exhaust pipe is the highest place it can find to rise and it brings moisture with it...which condenses on the pipe when it gets into the cold attic???

Any thing I can do to stop it?

Why didn't it happen with the old fan (replaced in the Spring)? I reused the vent pipe, so it is not like I can blame it on the new route of that.???
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#12
  Re: Bathroom vent fan dripping water by JosephP (So there I was lying...)
The exhaust pipe should be insulated the full length until it exits the roof. The vent should also run for 10 to 15 minutes after showering as well to get the rest of the moisture out.

Cold pipe = condensation inside the pipe.
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#13
  Re: Re: Bathroom vent fan dripping water by Robert Adams (The exhaust pipe sho...)
I guess that makes sense...just never realized it should be insulated. Wonder why the old one didn't have problems? Again, I thought it really odd when it started dripping on a day I didn't even run the fan.

another small project to add to the list. I just love playing in the attic

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#14
  Re: Re: Bathroom vent fan dripping water by JosephP (I guess that makes s...)
Might have been a more powerful fan. You can buy switches with timers


Phydeaux said "Loving your enemy and doing good for those that hurt you does not preclude killing them if they make that necessary."


Phil Thien

women have trouble understanding Trump's MAGA theme because they had so little involvement in making America great the first time around.

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#15
  Re: Bathroom vent fan dripping water by JosephP (So there I was lying...)
I Putin a humidity sensing fan. I couldn't keep paint on the walls before I did that. I also oversized the fan. It turns itself on and off now.

One other thing you can do is slope the pipe so condensate and any water that doesn't get blown out drains outside. It also forms a trap for heat when the fan isn't on. Warm air doesn't want to flow downhill.
Matt

If trees could scream, would we be so cavalier about cutting them down? We might, if they screamed all the time, for no good reason.
-Jack Handy

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#16
  Re: Bathroom vent fan dripping water by JosephP (So there I was lying...)
You also likely have a low spot in the vent pipe where the condensation has pooled thus the reason for the volume of water. It is not mentioned often, but the vent should always slope upwards thereby eliminating any low spots and any place for water to cool. With a puddle of cool water in the vent pipe, you have created a swamp cooler. Cold water will chill the humid air faster than just the cold air alone.

I believe you have a puddle in the vent pipe. Be careful when you crawl up in the attic to investigate so you do not dump the water into the vent fan and grill and spray the water all over the walls, shower curtain, sink, toilet, clean towels, and the floor. You can probably guess how I learned all of this.

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#17
  Re: Re: Bathroom vent fan dripping water by Anthony W (You also likely have...)
Thanks all...

Will look for low spot collecting water in vent pipe and insulate the pipe. I am pretty sure there is not a low spot though. I know this isn't ideal, but it was the way it was originally installed, and I just used the old pipe...it vents to the ridge vent on the roof, not a soffit vent. I assume running it to the soffit would correct this problem because it would not have a long run back down the pipe.

It is a new fan. Don't remember the CFM ratings, but significantly more than the old one.

I haven't been running it this week and it drips any how. This morning, I actually opened the door and turned on the fan for 2-3 minutes as soon as I got out of the shower and had no problem.
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#18
  Re: Re: Bathroom vent fan dripping water by JosephP (Thanks all...[br][br...)
funny I run the fan while I am in the shower to keep the moisture off the walls. Turn it off as I get out of the shower
Phydeaux said "Loving your enemy and doing good for those that hurt you does not preclude killing them if they make that necessary."


Phil Thien

women have trouble understanding Trump's MAGA theme because they had so little involvement in making America great the first time around.

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#19
  Re: Re: Bathroom vent fan dripping water by Bob10 (funny I run the fan ...)
I bet it wasn't single digit temps in SF on Monday and Tuesday? It was here.

Like hooks said, it is nice to have the extra moisture in the house for the winter.
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#20
  Re: Re: Bathroom vent fan dripping water by JosephP (Thanks all...[br][br...)
JosephP said:


Thanks all...

Will look for low spot collecting water in vent pipe and insulate the pipe. I am pretty sure there is not a low spot though. I know this isn't ideal, but it was the way it was originally installed, and I just used the old pipe...it vents to the ridge vent on the roof, not a soffit vent. I assume running it to the soffit would correct this problem because it would not have a long run back down the pipe.

It is a new fan. Don't remember the CFM ratings, but significantly more than the old one.

I haven't been running it this week and it drips any how. This morning, I actually opened the door and turned on the fan for 2-3 minutes as soon as I got out of the shower and had no problem.




What do you mean it "vents to the ridge vent"?

Even if it does not run to a soffit vent, there can still be a low spot. My bathroom fan ran to a through-roof vent. Along the way the flex hose was laid across the ceiling joists. Being unsupported, or supported only by the fiberglass insulation, it eventually sagged and created the low spot, then created the dripping. Then I created a mess in the bathroom. I have since replaced the fan, have an uninsulated metal hose supported along its length and always sloped upwards to the roof vent. Furthermore being in the northeast, I used a 20" pipe vent rather than those silly 6-8" tall vents that sit flush to the roof and would be covered by snow.

I am interested to know what you find in the attic.
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