Posted by Stan on July 24, 2004, 2:16 pm
I have a metal shop just over 120 sqft, concrete flooring. Just got a
gable mounted Leslie-Locke attic ventilator fan (is powered by 120
volt 60 Hz grounded circuit). I'm wanting to see if it would be
practical to power it (and possibly another one on the other end of
the shop at gable) by solar panels. The fans would only come on when
the thermastat reaches say 80+ degrees.
I'd like to have it where the shop stays cool at the hottest part of
the day (located in central Texas). What size of panels (to power each
fan) do I need and what price range are they? Most importantly, would
it be cost effective compared to just using electric? Anyone seen
instructions online for doing this? I'll be insulating the walls and
may apply kool coat to the roof to reflect the heat away. There are no
utility rebate programs unfortunately in the area.
Posted by CM on July 25, 2004, 7:36 am
The cheapest *short term* solution would be to power the fan from the
existing wiring - but I can't say whether it would be best in the long
run, as we don't know how high power prices might go!
If you want to try a solar powered attic ventilator, I'd suggest going
to an auto parts place and get an electric radiator fan. They are
available in various sizes up to 16" (maybe more?) and run on 12 volt
DC, thus not requiring an inverter. Many solar panels are designed to
produce 12 volt output, you'd just need one (or more) that equals or
slightly exceeds the running amperage requirement of your radiator
fan. Since motors typically demand more amps when starting than when
running, it may be necessary to add a large capacitor or battery and
switch (thermostat?) to store up extra power to start properly.
Posted by Robert Morein on July 25, 2004, 7:47 am
probably too late but a thermal chimney might be a better solution
Posted by SQLit on July 25, 2004, 6:08 pm
I applaud your idea. Not knowing how much power the fan needs makes it
impossible to size a system. Buy the time you get the panels, the inverter
and the batteries,,,,,
It will be easier to run them on 120v and WAY cheaper.
Central Texas is not noted for cool summers. Your fans will be running all
of the time. drawing in ambient air which could be over 100 degrees.
Not trying to rain on your parade
Posted by Gary on July 26, 2004, 1:13 am
Maybe it might be easier (and cheaper?) to return the Leslie-Lock and
buy one of the commercial solar attic fans? -- for example: