HELP - Leaking Bathroom Exhaust Vent

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jadm

New Member
Dec 31, 2007
918
colorado
We just installed a ventilation exhaust fan in our small master bathroom.

It is rated 110CFMs and is vented up to one of our roof vents (which we have had for umteen years) on the north side of the house.

Installer used 6" aluminum flex tubing and ran it at about 30* for about 13 feet to the existing roof vent.

Our temps for the past few days have been as low as -10°. Yesterday we hit 25°. RIght now it is 32°.

When my husband went to take his HOT shower this morning he turned on the fan and after a couple of minutes water began pouring out of the vent. It has gradually stopped...

My guess is that it has been soooo unusually cold here that steam from the shower froze as it hit the metal flex tubing and stayed that way until our temps began to rise today. The moisture is now thawing and taking the path of least resistance which happens to be a short slide down through the fan housing onto our floor....

I live in Colorado and our temps aren't usually this cold but I know a lot of you live in really cold climates that stay cold all the time - ie Alaska and parts of Canada and back East here in the states...You must have vents too...How do you keep them from building up condensation so they don't drain into your bathrooms???

Thanks for any of your ideas....
 
you could try insulating the flex tube so the steam doesn't condense and freeze in the pipe immediately- I'm not a professional- it's just what I would try if I were in your shoes.
 
yes, what he said!! Ours is a much shorter run and is insulated.
 
13 feet seems awefully long. My bathroom vent, runs quite literaly maybe 2-3 feet up and out. Part of the problem is the length. Outside of insulating I don't know what else to do, of course other than replacing it with a much shorter one.

Shawn
 
Is here anyway you could reroute the ductwork and install the vent to the underside of your soffit?
Use something like this?
I had used one similar to this, and it seems to work ok...Might alleviate the problem and allow the air to run horizontally and down vs vertically.
 

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shawneyboy said:
13 feet seems awefully long. My bathroom vent, runs quite literaly maybe 2-3 feet up and out. Part of the problem is the length. Outside of insulating I don't know what else to do, of course other than replacing it with a much shorter one.

Shawn
It is long because we have another bathroom fan (In another bathroom.) venting into the roof vent that is closer to it's position. Installer had to use another vent that happened to be farther away. (The other vent runs vertical and is only about 2-3 feet and we have never had a problem with it. That fan is rated lower than our newer one - rated at 70CFM.
 
Thanks for the ideas. I will call my installer and run these ideas past him and see which one he thinks will be the best.

I am thinking the insulating one and it will be easier to wrap insulation around the existing tubing rather than adding another vent to the soffit and re-routing the tubing....

Path of least resistance!
 
They are supposed to be insulated. The installer screwed up by not insulating it. In fact, they sell the premade insulation wrapped 4" duct for just this purpose. It looks just like the preinsulated flexible furnace ductwork but only 4". The insulation prevents the hot bath air from condensing on the duct and running back into the bath. There is no freezing happening, just regular condensation like on a cold beer bottle. The longer the run and colder the attic, the worse the effects of no insulation on the duct.
 
have also heard to let them run for 10-20 minutes after you get done to let them dry out good ?
rn
 
You should have a flap like that on the roof vent as well as on the ceiling fan. You can also buy another one for inline.
 
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