So I recently finished gutting and remodeling my small bathroom which sits in a dormer. 60" W x 80"D x 80"H
The original bathroom didn't have a ceiling vent.
Since there is no attic access to install, i ended up cutting a large opening so i could physically get my body into crawl space from bathroom.
I used an insulated flexible duct to vent to roof which was about a 2-3' distance. the duct is securely connected to both roof vent and unit.
So my issue is when the door is shut and the fan is on, the mirror in the bathroom will fog up about halfway. Not sure if thats normal?
If I have the heater and fan on there is no fog on the mirror.
When I'm outside the house when the vent is on, on a cold day, the vent is definitely moving the air out as you can see it.
My only reasoning for the mirrors fogging up is that the bathroom is so small that the vent can't move the moist air fast enough?
The bathroom itself is fog free during shower.
The unit itself is actually rated for a larger bathroom.
Is this normal?
Thanks

 

Yes it's normal for a cold mirror to fog up when you take a shower. It has nothing to do with the vent. It is the temperature of the mirror. If you heat the room prior to a shower it will lessen the effect. Long shower... it might still fog up.

 

thank you. that makes a lot of sense.

have a great day

Owe

 

How much of a gap is under the door?
There needs to be a gap there for make up air.