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Bathroom fan

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Jdeal1

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So at the grate it can hold paper we shower with the door open there is no fog on the mirror. We leave the fan running for 30 afterwords this is the fan I can stick my finger through the openings and feel that the baffle isn’t stuck closed. But I feel like there is still some moisture on my wall next to my shower. Is it because my shower is an I closed space?
 

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DFBonnett

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Same issue in my daughter's condo. Inner portion has toilet and stall shower with no window. Fan works but I suspect just insufficient air circulation.
 

Greal

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Where are you located? If that is an exterior wall, I'd expect it to be much worse in the colder months when the cold wall encourages condensation.
 

pjones

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I run my fan on a dehumidistat. It turns on when the humidity increases and off when it drops back down again. That control is run in parallel with my timer so I can still run it to remove smells. You may want to consider installing a dehumidistat so it can run as long as it needs after your shower.

The other thing I’m noticing is the fan you have installed will not move much CFM. You may be able to get more air movement by installing a different fan.

Air won’t move unless you have airflow so make sure your door is undercut so fresh air can enter the room as the humid air is exhausted.

Don’t expect the inside of the shower to dry out as quickly as the rest of the bathroom. I’m not sure if that was part of tour concern but if it is then you would be better off buying a squeegee and running that down the shower wall after every shower.
 

Johnboy555

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Is there an attic above the bathroom? If so think about an attic mounted in-line exhaust. There's hardly any noise, and can more than double/triple the amount of air they pull out. Just go to YouTube and search "inline bathroom exhaust fan" to get a better idea.
 

Jeff Handy

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Check the exhaust fan vent cover where it leaves the house.

If there are little plastic vanes, they can get fuzzy and not open properly.

Or it can be an aluminum flapper door which might also need fuzz cleaned from it.

Otherwise, as suggested, install a bigger and better fan with more cubic feet per minute.
 

Jim greengo

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That motor looks pretty rough,probably not turning very fast.
I'd buy a cheap $20 50cfm exhaust fan at nearest box store.
Pull the motor and mounting plate out and install it back in yours,should go right in there with no changes.
 

femgroup

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Check the exhaust fan vent cover where it leaves the house.

If there are little plastic vanes, they can get fuzzy and not open properly.

Or it can be an aluminum flapper door which might also need fuzz cleaned from it.

Otherwise, as suggested, install a bigger and better fan with more cubic feet per minute.
Is there a quick and dirty ratio to determine the fan specs? Size vs CFM?
 

zannej

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@femgroup to determine cfm you find the volume of the room in cubic feet (length x width x height) and divide by 7.5 and round up to the nearest cfm available for fans. http://www.airzonefans.com/Fan_Sizing_Guidelines_Red.pdf
I have a room that is approximately 8'w*5'L*9'H, (360/7.5=48) thus I need a fan with minimum 50cfm.

Moisture can sometimes hover in alcoves, but if the fan is sufficient cfm, there is probably some obstruction somewhere along the way. Frodo's suggestion of checking the outside vent is a good idea.
 

femgroup

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@femgroup to determine cfm you find the volume of the room in cubic feet (length x width x height) and divide by 7.5 and round up to the nearest cfm available for fans. http://www.airzonefans.com/Fan_Sizing_Guidelines_Red.pdf
I have a room that is approximately 8'w*5'L*9'H, (360/7.5=48) thus I need a fan with minimum 50cfm.

Moisture can sometimes hover in alcoves, but if the fan is sufficient cfm, there is probably some obstruction somewhere along the way. Frodo's suggestion of checking the outside vent is a good idea.
Good info and just what I was looking for.

Thanks!
 

zannej

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Good info and just what I was looking for.

Thanks!
You're welcome. I researched it when trying to figure out what cfm fans were needed for my bathrooms. I kept notes on it so I would remember. There are other formulas to figure it out, but the divide by 7.5 was the simplest one I found. It's worth noting that you can subtract cubic feet for solid objects like vanities. I didn't bother with that and rounded up a little since my measurements aren't exact. Better to go higher than lower.

Jdeal1, I hope you get this issue resolved.
 
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