CT seems like the right crowd to get the sort of input I'm looking for, but I couldn't find a more appropriate section than 'Wiring Closet' to ask this.
long story short: i have an attached 2 car garage that has an insulated rollup door, dual-pane window, and is fiberglass insulated (ceiling as well as walls). above the garage there is attic space (this attic space is not partitioned or compartmentalized in any way from the rest of the attic space above the livable areas of the house). in the summer, esp when there are two recently-driven cars parked inside, the garage is an oven. the cars continue to radiate heat for hours and there's nowhere for the heat to go.
a few months ago i had a contractor cut a couple of vent-sized (14"x5") openings through the exterior wall of the garage, about 6-8" above the floor, which has helped somewhat with air flow. of course this being winter it's hard to get a sense for how much this will help when it gets hot.
i've been intending to also install a ventilation fan that would pull in cool(er) outside air through those holes and exhaust the hot air to the outside, ideally through the ceiling so i don't have yet another hole in the wall at eye-level or above.
the challenge is that I don't want to exhaust the possibly-CO-containing air into the attic where it could get into the rest of the house. a brief conversation w/ my local city building inspector suggested this would be a violation of code anyway.
i came across this product from a company called Natural Light which seems almost ideal for my needs: a roof-mounted ventilation fan that comes with ducting to connect to a ceiling mounted intake vent with a heat-activated damper (close in case of fire) and thermostat-controlled switch. the all-in-one convenience is great as well as the fact that it's made for exactly my situation. the only problem is that it's a solar-powered fan.
now, i don't have anything against solar power per se (in fact i have a grid-tied solar PV system with a number of large panels on my roof) but for this application i think it's a bad idea: there's no battery, so the fan will only run when there's sun. the cars are likely to be put into the garage late in the day when there may not be much sun left (although there is more sun for longer in the summer, when it's likely to be hotter) and i expect the fan will need to run for more time to effectively eliminate the heat. so i'd prefer something designed to be hard-wired, which i could then wire up to be controlled via a relay or somesuch.
i looked around for other exhaust fans: besides the bath exhaust fans (which are too small and probably not suited for longer run times), i found this which is a ceiling-mounted fan that exhausts into the attic (with fire damper), or others which are basically small whole-house fans that also exhaust to the attic. it's not clear to me if one could easily / safely add ducting to one of these solutions and vent it through the roof and i couldn't find any mention of anyone doing such a thing online.
so i went back and called Natural Light, the manufacturer of the first solution. i found out they don't offer their attic fans without the solar panel but learned that the motor is basically a DC motor that seems to accept a range of .
So.. i got to thinking: can i 'convert' this solar-powered attic fan into a relay-controlled fan which is powered via mains power through a DC transformer?
obviously this should be possible, but i'd want it to be safe (code-compliant), and reliable.. esp. able to tolerate high temps (>120*F on a hot day) in my attic. have any of you done anything like this, or have any tips or guidance to offer? can i just buy an off-the-shelf DC transformer like one of these? is there anything else I need to bear in mind? any tips on the best way to make this a relay-controlled circuit?
and a follow-on question: the 850cfm fan requires slightly more sq ft of intake vent than i have cut through the side wall of the garage (1.13 sq ft is the stated requirement vs the 0.9 sq ft that i actually have). it turns out because of the spacing and placement of the studs in the (load-bearing) wall it will be hard to cut a third vent of this size.. i'm assuming i can just reduce the current to the motor to run it at a slightly slower speed to compensate?
thanks!
long story short: i have an attached 2 car garage that has an insulated rollup door, dual-pane window, and is fiberglass insulated (ceiling as well as walls). above the garage there is attic space (this attic space is not partitioned or compartmentalized in any way from the rest of the attic space above the livable areas of the house). in the summer, esp when there are two recently-driven cars parked inside, the garage is an oven. the cars continue to radiate heat for hours and there's nowhere for the heat to go.
a few months ago i had a contractor cut a couple of vent-sized (14"x5") openings through the exterior wall of the garage, about 6-8" above the floor, which has helped somewhat with air flow. of course this being winter it's hard to get a sense for how much this will help when it gets hot.
i've been intending to also install a ventilation fan that would pull in cool(er) outside air through those holes and exhaust the hot air to the outside, ideally through the ceiling so i don't have yet another hole in the wall at eye-level or above.
the challenge is that I don't want to exhaust the possibly-CO-containing air into the attic where it could get into the rest of the house. a brief conversation w/ my local city building inspector suggested this would be a violation of code anyway.
i came across this product from a company called Natural Light which seems almost ideal for my needs: a roof-mounted ventilation fan that comes with ducting to connect to a ceiling mounted intake vent with a heat-activated damper (close in case of fire) and thermostat-controlled switch. the all-in-one convenience is great as well as the fact that it's made for exactly my situation. the only problem is that it's a solar-powered fan.
now, i don't have anything against solar power per se (in fact i have a grid-tied solar PV system with a number of large panels on my roof) but for this application i think it's a bad idea: there's no battery, so the fan will only run when there's sun. the cars are likely to be put into the garage late in the day when there may not be much sun left (although there is more sun for longer in the summer, when it's likely to be hotter) and i expect the fan will need to run for more time to effectively eliminate the heat. so i'd prefer something designed to be hard-wired, which i could then wire up to be controlled via a relay or somesuch.
i looked around for other exhaust fans: besides the bath exhaust fans (which are too small and probably not suited for longer run times), i found this which is a ceiling-mounted fan that exhausts into the attic (with fire damper), or others which are basically small whole-house fans that also exhaust to the attic. it's not clear to me if one could easily / safely add ducting to one of these solutions and vent it through the roof and i couldn't find any mention of anyone doing such a thing online.
so i went back and called Natural Light, the manufacturer of the first solution. i found out they don't offer their attic fans without the solar panel but learned that the motor is basically a DC motor that seems to accept a range of .
So.. i got to thinking: can i 'convert' this solar-powered attic fan into a relay-controlled fan which is powered via mains power through a DC transformer?
obviously this should be possible, but i'd want it to be safe (code-compliant), and reliable.. esp. able to tolerate high temps (>120*F on a hot day) in my attic. have any of you done anything like this, or have any tips or guidance to offer? can i just buy an off-the-shelf DC transformer like one of these? is there anything else I need to bear in mind? any tips on the best way to make this a relay-controlled circuit?
and a follow-on question: the 850cfm fan requires slightly more sq ft of intake vent than i have cut through the side wall of the garage (1.13 sq ft is the stated requirement vs the 0.9 sq ft that i actually have). it turns out because of the spacing and placement of the studs in the (load-bearing) wall it will be hard to cut a third vent of this size.. i'm assuming i can just reduce the current to the motor to run it at a slightly slower speed to compensate?
thanks!