Ducting Systems and Air Ventilation - Attic Fan
Doityourself.com community forum was created to provide answers to all questions related to home improvement and home repair. Doityourself community can help you find information about how-to topics on small fixes to large remodeling projects. With comprehensive how-to content and expertly moderated community forums DoItYourself.com makes it easy to tackle even the most complex home improvement projects.View Full Version : Attic Fan
mwh98
07-20-09, 04:12 PM
We have triple digit temps for days on end here in San Antonio and our attic temps are like a sauna.
I want to install a power mushroom vent in place of an existing non-powered mushroom vent in the roof. I have enough soffit vents to draw from in addition to the attic stairs in the garage. I have a few questions.
1. The thermostat is on a 18" pigtail off the fan motor. May I relocate the thermostat further away from the fan motor since the fan will be about 12 feet overhead in the attic roof and adjusting the thermostat would be impossible once placed. I would just dial down the temp from the recommended 105 degrees to around 80 degrees to compensate for the temp difference due to height.
2. Where woudl I find a "safety switch" to automatically interupt power to the fan when the gas furnace fires up?
Thanks,
Mark
San Antonio Texas
I want to install a power mushroom vent in place of an existing non-powered mushroom vent in the roof. I have enough soffit vents to draw from in addition to the attic stairs in the garage. I have a few questions.
1. The thermostat is on a 18" pigtail off the fan motor. May I relocate the thermostat further away from the fan motor since the fan will be about 12 feet overhead in the attic roof and adjusting the thermostat would be impossible once placed. I would just dial down the temp from the recommended 105 degrees to around 80 degrees to compensate for the temp difference due to height.
2. Where woudl I find a "safety switch" to automatically interupt power to the fan when the gas furnace fires up?
Thanks,
Mark
San Antonio Texas
furd
07-20-09, 09:59 PM
1. Yes, provided that you follow all the applicable electrical codes for your jurisdiction including type of wiring method (cable or conduit), size of conductors for field wiring, all splices in approved junction boxes etc.
2. Is your furnace located in the attic? Does it use attic air for combustion (i.e. it is less than a 90+% AFUE model)? If yes to these questions then you would have to have a relay with a control voltage to match the furnace (either primary voltage or secondary control voltage) depending on how the relay senses furnace operation with the relay contacts in series with the attic fan power. This may be readily available from the furnace manufacturer or it may need to be field engineered and installed. Again, local codes would prevail.
2. Is your furnace located in the attic? Does it use attic air for combustion (i.e. it is less than a 90+% AFUE model)? If yes to these questions then you would have to have a relay with a control voltage to match the furnace (either primary voltage or secondary control voltage) depending on how the relay senses furnace operation with the relay contacts in series with the attic fan power. This may be readily available from the furnace manufacturer or it may need to be field engineered and installed. Again, local codes would prevail.