First time problem (Bathroom exhaust)

[SS MAYFLOAT]

Last day or so the temps outside have been in the single digets. I now have some water dripping out of my bathroom exhaust fan. I'm suspecting that the residule warm air flowing up an out of the vent pipe has collected condensate on the outside of it. Isn't there surpose to be a flap to shut off the air flow going through the vent when the fan is off? My fan is an old style and don't remember seeing any flapper on it.<br /><br />Anyone have any ideas to an easy fix? Thanks

 

[sangerwaker]

Re: First time problem (Bathroom exhaust)

Should be a flapper for sure wher it exits the house, either through roof or wall. There's usually one at the fan too.<br /><br />Is your vent pipe insulated? Sounds like that's the problem from here anyway.

 

[SS MAYFLOAT]

Re: First time problem (Bathroom exhaust)

Nope, it is just a 3" galvanized vent pipe that goes up through the roof. <br /><br />I've been putting in new windows and doors blocking incoming drafts. Since I use a wood burner for my prime source of heat, I'm thinking that the WB is forcing the backdraft of the bath/xfan vent. I may need to also figure a way to bring in outside air for the proper combustion of the WB since I seem to be making the house more air tight.

 

[sangerwaker]

Re: First time problem (Bathroom exhaust)

There's the problem. That pipe needs to be insulated to stop the condensation. Too great of a temperature difference between inside and outside the pipe. You can just use the pre-insulated flexible duct, but it will cut down the performance of the fan.<br /><br />Anytime you exhaust warm, heated air through an unheated space (attic), the vent pipe needs to be insulated. This realistically only applies where the attic can get quite cold. Like your neck of the woods or mine.

 

[KRS]

Re: First time problem (Bathroom exhaust)

Maybe not in AZ

 

[fireship1]

Re: First time problem (Bathroom exhaust)

In the HVAC trades they use pipe wrap that is on a roll. It's black foam and it can be wrapped around irregular bends, large to small reductions...etc. Maybe you could check a plumbing supply shop or the usual suspects (Home Creepo, Lowes) and find a roll of it. Would be easy to wrap up your exhaust pipe with it.

 

[LubeDude]

Re: First time problem (Bathroom exhaust)

Originally posted by SS Mayfloat:<br /> Since I use a wood burner for my prime source of heat,

If your woodstove is and older one that gets its air from inside the house instead of an outside source, you have to remember that the stove will need to get air from somewhere and it may be the fan in the bathroom is the source. Houses with wood heat cant be completly air tight unless there is a fresh air source from somewhere else to the stove.

 

[SS MAYFLOAT]

Re: First time problem (Bathroom exhaust)

Thanks everyone! I'm going out to my HVAC supplier and get some 3" armafex insulation to cover it. It has only happened 1 time since 7 years at this house. However, it may have been doing it all along, but not enough to leak inside the house. I'm thinking I may have a bigger mess above the bathroom ceiling. Thinking this maybe a bigger priority than I expect.<br /><br />As for the woodburner, I'm going to have to make a duct that comes in from outside to the WB for the makeup air. Just not sure what size I should use? 4" or 6" or two 4"?