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.

Christopher Nelson wrote:
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

--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel

On Wed, 14 Nov 2007 18:48:44 -0800 (PST), Christopher Nelson
wrote:

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.

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.
--
41 days until the winter solstice celebration

Mark Lloyd
http://notstupid.laughingsquid.com

"Never underestimate the power of stupid
people in large groups"

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.




"Christopher Nelson" wrote in message
...
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.

"Christopher Nelson" wrote in message
...
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.

You'll end up throwing out a lot of heat/cold unnecessarily.

Use timer switches and just wire them in parrallel.

Bob

On Nov 15, 1:22 am, "Bob F" wrote:
"Christopher Nelson" wrote in message

...

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.

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.

wrote:
On Nov 15, 1:22 am, "Bob F" wrote:

"Christopher Nelson" wrote in message

...


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.

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.

--
Robert Allison
Rimshot, Inc.
Georgetown, TX

On Nov 15, 7:57 am, wrote:
On Nov 15, 1:22 am, "Bob F" wrote:





"Christopher Nelson" wrote in message

...

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.

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.- Hide quoted text -

- Show quoted text -

You could include powered dampers in the ductwork from each bathroom
controlled by that bathroom's switch. Something like these:

http://www.smarthome.com/3080.html?src=WG1002278

On Nov 15, 9:15 am, Robert Allison wrote:
wrote:
On Nov 15, 1:22 am, "Bob F" wrote:

"Christopher Nelson" wrote in message

...

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.

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.

--
Robert Allison
Rimshot, Inc.
Georgetown, TX- Hide quoted text -

- Show quoted text -

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!

On Nov 15, 9:21 am, DerbyDad03 wrote:
On Nov 15, 7:57 am, wrote:



On Nov 15, 1:22 am, "Bob F" wrote:

"Christopher Nelson" wrote in message

...

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.

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.- Hide quoted text -

- Show quoted text -

You could include powered dampers in the ductwork from each bathroom
controlled by that bathroom's switch. Something like these:

http://www.smarthome.com/3080.html?src=WG1002278

Wow! For $110 a piece, how many centuries does it take to pay back
the losses for not using the dampers?!?

On Nov 15, 12:17 pm, Christopher Nelson wrote:
On Nov 15, 9:21 am, DerbyDad03 wrote:





On Nov 15, 7:57 am, wrote:

On Nov 15, 1:22 am, "Bob F" wrote:

"Christopher Nelson" wrote in message

...

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.

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.- Hide quoted text -

- Show quoted text -

You could include powered dampers in the ductwork from each bathroom
controlled by that bathroom's switch. Something like these:

http://www.smarthome.com/3080.html?src=WG1002278

Wow! For $110 a piece, how many centuries does it take to pay back
the losses for not using the dampers?!?- Hide quoted text -

- Show quoted text -

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 's
suggestion of using 2 fans? Should I be honored that you felt I was
the only one worthy of being picked on? ;-)