I've heard of bathroom fans which have the blower at the top of the duct, just under the roof rather than just above the bathroom ceiling. And I heard a suggestion that they can be used to vent multiple bathrooms with one blower. But I'm having trouble imagining how that would be wired so it could be turned on in either of two bathrooms. That's not a three-way switch.
Unless you have the same circuit serving all bathrooms, you'd probably have to use a relay somewhere.
nate
Right. It's not a 3-way switch. You'd wire two ordinary (SPST) switches in parallel. Use only one circuit to supply power no matter which switch is being used.
Correct, it's two single pole switches in parallel. Install a junction box in the attic with the feed in it. Run a two wire cable to the fan motor. Run a two wire cable to each bathroom switch. Connect the neutral in the junction box to the fans neutral. Connect the hot in the junction box to both white wires going to the switches. Connect both black wires coming back from the switches to the black that goes to the motor.
You'll end up throwing out a lot of heat/cold unnecessarily.
Use timer switches and just wire them in parrallel.
Bob
I think you wind up throwing out a lot of heat/cold unnecessarily with this approach regardless of how it's wired. The blower will always be pulling air out of all the bathrooms anytime one of them needs the fan on.
Personally, I think using quiet quality individual bath fans is the better solution.
This fan system was used on one of my jobs and I paid particular attention to it because I had not seen one before. The fan was not at the roof, but in the attic and fed three bathrooms. The switch turned on both the fan and opened a damper which only allowed air to be pulled from the room that was switched on. The biggest problem was that it was so quiet, unless you looked at the switch and noticed that it was in the on position, there was nothing to tell you to turn it off when you left the bathroom.
You could include powered dampers in the ductwork from each bathroom controlled by that bathroom's switch. Something like these:
re: The biggest problem was that it was so quiet, unless you looked at the switch...
A timer or humidistat switch solves that problem. I installed timers since the kids (and wife) would leave the fan on to finish clearing their bathroom and then forget about it...and we're not talking about fans that you can't hear!
Wow! For $110 a piece, how many centuries does it take to pay back the losses for not using the dampers?!?
You'll note that I used the words: "Something like these". There are ceratinly cheaper models available. I apologize for not offering a link to the lowest priced option. I'll be more careful next time in case the power of my suggestion is so overwhelming that the reader can't resist clicking on the link and immediately placing an order.
BTW...wouldn't your response also apply to snipped-for-privacy@optonline.net's suggestion of using 2 fans? Should I be honored that you felt I was the only one worthy of being picked on? ;-)
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