I keep my roof fan off in the spring and the fall, when it's warm during the day but would otherwise require heat at night (or tomorrow), so that the attic heats up and it heats my home. It means I don't have to use the furnace for a couple weeks times two, four weeks a year.
3 way not required. Sw 1 powers the thermostat through the black wire. Switch 2 powers the fan (fan side of 'stat" through the red wire, from the black wire at the switch. Sw1 on means the fan is on thermo, Sw1 AND Sw1 on means fan on direct. Sw2 only on, fan is off
Inquiring minds want to know..... Why does the OP want to run the attic fan without the attic being hot? Mine is wired with a switch in series with a thermostat on the fan, just like his is now. Works fine for me. Some places it's desirable to have them run for dehumidification, but for that you wire in a control that measures temp and humidity.
If he does want the option of running it when it's not hot, then the SPDT switch is the way to go. It's simple and won't look like a hack job, which is what he'll have with two switched, sided by side.
Personally, I don't like it when I have no override for things like this.
Yes, those space capsules with 50 switches side by side really look lke hack jobs.
Good question. I am ~considering~ running the attic fan without the attic being hot due to a COMPLETELY different subject and thread:
Like I said, completely different thread and I don't want to hijack this one. I respectfully suggest we start new thread if folks want to comment on this aspect.
-OP
Actually called SPST. SPDT is the same as a 3-way switch.
If the power goes to the fan first (power does not go to the switch then the fan) you can just change the wiring at the fan.
A center off SPDT switch can not be had in a "wall switch" configuration that looks like a normal house switch so IT will look like a hack. A double gang switch is an everyday situation -even triple gang switches are very common. In fact you can buy 2 witches together in one unit that fit a single box and use a duplex receptacle plate.
What the situation calls for is a single pole, double throw switch with "Center OFF."
I haven't seen them offered in the form factor of standard 120 volt toggle switches but I have seen them in the form that mounts in a 1/2" hole in sheet metal.
BUT "you made me look."
Check out the Levitor 5685-2A. It's a single-pole, double throw, center off, maintained contact Decora switch.
It might be on the expensive side but with one switch you can choose: ON, OFF, Thermostat.
I posted a link a couple days ago for one in Decora.
for a single switch solution you could use a spdt like the Leviton 1285
You will need a Center OFF switch. Hot wire from the panel goes to common connection on the switch, other two wires dont matter which but one goes to the normal connection and the other connects to a point that bypasses the T stat. Mine was wired directly to the breaker panel, no switch. What I did was wire the switch across the T stat and I located this switch by the attic entrance so I can turn the fans on full when I go up there. Switch only selects normal operation or Bypassed Tsat operation ...OFF/ON is done at the breaker panel.
Jimmie
Jimmie
Thats the way mine is.
Jimmie
Correction No its not, I shouldnt post when half asleep. All you need is a two way switch connected across the tsat if you use the breaker for on/off.
Jimmie
Ya know, if you don't have at least one square foot vent opening for 300 square feet of vented space, you have no warranty on most shingles, such as Certainteed and Owens-Corning. Verify warranty details at 1-800-ROOFING. But putting that aside, the main aim is to get any BTU's that make it up to the attic to be removed. Problem with your plan is that a roof fan will also pull conditioned air from within the wall spaces, causing a net loss in your efforts to keep warm in, cold out. Also, I've gotten damn tired of dealing with sites with damage caused by an overheated fan. A lot is depending on an overtemp sensor supplied by the lowest bidder in China. Those fans get forgotten about, at the hottest part of the roof, and all the worst if you turn on the fan and then forget it. Better to put a timer switch to shunt the t'stat if you feel you really must. It would be nice to have a remote-reading temperature sensor in the eaves area, displayed near the timer switch.
You're right!!!
Thanks.
P&M?
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