# Installing A Bathroom Fan In A Cold Climate



## tuchodi (Oct 24, 2009)

I am adding an Ensuite Bathroom to the Master Bedroom and want to know for a colder climate (Central BC Canada Temp range from -10 to -30) the best way and where to install the bathroom fan Exhaust Vent. Should I go straight up through the roof or go out sideways and vent throught the end gabble which is about a 20' run. Also what kind of a cap is the best for the vent outside to reduce the possability of Ice build up.


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## user1007 (Sep 23, 2009)

I guess you could do either but I would pick the shortest run. 20' is quite a long way so make sure the fan you get is going to move enough air through that run or things could just sit in the duct. 

If you go through the roof, they make a roof cap that sits parallel to the roof. You just lift off shingles, flash it, replace the shingles.


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## tuchodi (Oct 24, 2009)

sdsester said:


> I guess you could do either but I would pick the shortest run. 20' is quite a long way so make sure the fan you get is going to move enough air through that run or things could just sit in the duct.
> 
> If you go through the roof, they make a roof cap that sits parallel to the roof. You just lift off shingles, flash it, replace the shingles.


I have a Metal Roof so does that make a differance except in the way I will have to seal the cap flashing to the roof. I was mostly worried about the moisture venting and if there would be a build up of ice or a freezing problem going straight up. Straight up would be the easiest. Do I also need to insulate the short run of pipe that will be going throught the attic?


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## user1007 (Sep 23, 2009)

Could be a problem given the temps you mention. Wait and see what others post. Does the attic drop below freezing too?


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## tuchodi (Oct 24, 2009)

sdsester said:


> Could be a problem given the temps you mention. Wait and see what others post. Does the attic drop below freezing too?


Yes the attic would be what ever the Temp is outside.


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## Gary in WA (Mar 11, 2009)

20' is a fairly short run, considering the other option. http://www.efi.org/factoids/bathroom_sizing.html

I would insulate the metal fan box, the ducting (solid smooth metal), and the gable area directly around the duct/hood connection. Use at least the R-value required for ducting, if not double. Start with a 22* elbow at the fan, run up high enough to another elbow, then pitch down to the hood in the remaining length to drain the condensation out at the gable. Foil tape all seams, even the individual elbow's. Support ducting every 4', no flex pipe: http://www.pse.com/SiteCollectionDocuments/residential/1210_RES_Moisture.pdf Be aware not to over-size motor, drawing gas appliance's exhaust for make-up air. Make sure holes to drain condensate at hood are set away from house and not over wood that could rot. Use multiple doors vinyl hood, not one piece metal that could freeze-up easier.

Be safe, Gary


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## tuchodi (Oct 24, 2009)

Thanks Gary: 
Great points and now it doesn't seam to be such a problem with the 20' run.


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