Big enough bathroom vent FAN?

[SumpChump]

Bathroom is small, no windows. 1991 single story ranch stick built home. Small but it contains a full tub and shower bathroom. Measures 8feet deep by 5feet wide. Has vanity with drawers if that affects any volume calculations.

My math tells me that it's about 400 cubic feet plus or minus 30cubic feet.

My current contractor grade vent fan lists 60cfm and 3 "sones". Is that adequate?

I'm having a new roof done and they are willing to run the vent out the shingled roof for me. So this is an opportunity to put in a new vent fan to replace this (potentially?) undersized or (tired?) 20+year old vent.

Your thoughts...tips...etc.

 

[donnyj08]

if you are going to have it all apart anyway it makes sense to upgrade the unit while you are there.

A nice bath fan only cost $100-200 depending on the options you choose.

if it were me i would upgrade and have it vented proper with 4" galvanize through the roof with a proper vent as you have mentioned. Good Luck!

 

[dishdude]

Those 50 CFM fans are lousy, if the mirror is all fogged up when you get out of the shower you know it is way too small. I put a 110 CFM in when I remodeled a few months. Agree with the 4" duct!

 

[hattaresguy]

http://www.amazon.com/Panasonic-FV-11VQ5...Z8P6C2Y5A61RSQ2

 

[CT8]

Add to this And I am not probably saying correctly there needs to be a way for at least an equal amount of air to enter the room as is being vented out.

 

[hemitom]

Replaced my fan a few years ago when we did our bathroom .
Had a uselees fifty cfm fan, went with a 110 cfm and 4" duct made a world of difference our bathroom is about 600 sf. we have mirrors that go almost to the ceiling ,and after a long hot shower the top few inches will have steam on them but clear almost immediately when you turn the shower off. And if your bathroom is sealed tight you will need to have some fresh air to bring in or you will have negative pressure which would cause excessive steam.. usually the gap between the bathroom door and floor is sufficent to allow air in..

 

[ecotourist]

I'd think about adding a light pipe while you're at it. Supposedly less problem than a sky light but still lots of glorious light.

 

[Wolf359]

If you've got the money and like a quiet fan, I'd put in one of these:

http://www.electricbargainstores.com/Fantech-Premium-Bathroom-Exhaust-Fan-s/1852.htm

You can put the fan motor away from the bathroom so that you won't even really hear it if it's far enough away.

 

[JTK]

Originally Posted By: hattaresguy
http://www.amazon.com/Panasonic-FV-11VQ5...Z8P6C2Y5A61RSQ2


Totally agree on the Panasonic bathroom exhaust fans. I haven't gotten around to swapping them out in our current home yet, where the exh fans are junk. In our last home I installed the one linked above in one bathroom, then another Panasonic with a heater, light, nightlight and vent fan in the other bath. That one was a beast as well and super quiet.

The key to a good bathroom exhaust fan is how well you have them ducted to the outside. I used 4" PVC pipe and under soffit vents.

 

[SumpChump]

Very interesting.