View Full Version : Bathroom shower vent

11-23-2009, 11:14 AM
I have a house that was built in the 30's or 40's. There is no bathroom exhaust vent, and the room itself has no attic. It does however, have an old fan/heater that is recessed in the wall. My question is could I put an exhaust fan in where the wall heater is now, since there is electrical already run to it? The one big problem I can see is there would be no wall switch, so I was wondering if anyone knew if there were exhaust fans you could get that have their own on/off switches built in. (the old fan/heater had a switch on top). As far as the venting itself, I was thinking I would either go up throught the wall and out the soffit, or straight out through the wall. Any help on either count is appreciated.

11-23-2009, 05:25 PM
It shouldn't be all that hard to add a switch. Panasonic makes a nice through the wall ventillation fan. http://www.panasonic.com/business/building-products/ventilation-systems/products/whisper-wall.asp

You'd just need a section of wire, an old work box, and a switch.

11-24-2009, 05:32 AM
The one big problem I see with the idea is that the heater/fan was usually installed near the floor, and exhaust fans work better when they are near, or in, the ceiling, since that is where the steam and humidity are,

11-24-2009, 08:24 AM
I guess I should have said where the heater/fan is located. It is on the other side of the room from the only switch box, and it is about six feet up on the wall, just higher than the shower--so I would think it would be okay as far as getting most of the steam. The room is approx. 8 feet by six feet so not real big.
Thanks to who has responded so far. Again, if anyone knows of a
"switchless" vent or fan (one that does not need to be wired to a switch box) I would be interested in that.
Not sure how hard it is to run a vent up through the ceiling and out the soffit. Would just a basic fan/light require much rewiring? Right now there is just one light switch with a three prong plug socket above it on the same switch plate.

11-24-2009, 09:31 AM
Assuming that the heater wasn't also controlled by some other switch (other than the CB), and you can accept a control switch below it, it would be quite simple to use the existing wiring to add a fan and a switch. Running a switch to by the door next to the other switch in the room might be a lot harder...depends on where the feed for the heater originates. If the heater's power originates in the same box where the outlet and switch are located, it would be easy to put the switch there. No way to tell without looking. Now, if that wall isn't an exterior one, the fan I linked to wouldn't work. While it is done, my personal opinion is it's a lousy way to duct moisture out of the house by using the sofit. I'd rather do it through the wall or a gable end wall, or the roof. To each their own. A properly functions sofit vent is sucking air in, and you're trying to exhaust it. Some of that hot humid air is going to end up inside the house, but now in an area you can't see. True, it may not run all that long, but a large family with multiple showers one after the other (or one teenager!), could dump a lot of moisture out. In the winter, that could actually accumulate and maybe freeze in the wall. I'd much prefer to get it out and stay out.

11-24-2009, 11:39 AM
thanks Jim,
Great advice and information. The heater/fan is on an outside wall. I am pretty sure (but not positive) that the wiring originates from the lone switch in the room.
What would you recommend as far as venting through the wall? Just a simple dryer vent type setup or something more elaborate? Assuming I mount the new vent where the old heater is, I wouldn't have very far to go to get outside. Could that create cold air coming back in in winter?
Thanks for all your advice so far.

11-24-2009, 11:45 AM
Just checked out the link you sent--that could be exactly what I need. Thank you!

11-24-2009, 07:29 PM
If the power to the current heater comes from the box where the light switch is now, then making the box bigger (or using a dual-switch instead of a single) to control the fan would be simple. Otherwise, add one below the fan in the same stud bay.

11-25-2009, 01:34 PM
I looked into buying the Panasonic vent fan. I have a question for anyone who wants to help. If I get this particular fan I would be mounting it on an outside wall with not too much ductwork before hitting outside air. The vent duct is 8" in diameter. The fan has a built in damper to prevent air from coming back in.
Would anyone else be concerned about cold Michigan winter air coming back in through the fan (even with the damper) considering it would only be a matter of inches between the outside of the fan and the inside?
I am not familiar with these kinds of fans so any info/advice is appreciated.