An exhaust fan will require intake air. This can be as simple as
opening a window or using operable louvers opened when the fan
unit comes on. The exhaust fan can be mounted in a window, cut
into a sidewall, punched through a roof. A roof penetration
requires the most to keep it rain tight.

Knock your lights out he
http://www.grainger.com/Grainger/wwg/start.shtml

Roof mount:
http://www.grainger.com/Grainger/wwg/productIndex.shtml?from=Search&newSrch=yes&operato r=keywordSearch&search_type=keyword&action=Go%21&Q ueryString=roof+top+exhaust&submit.x=0&submit.y=0

Wall mount:
http://www.grainger.com/Grainger/wwg/productIndex.shtml?operator=prodIndexRefinementSea rch&originalValue=exhaust+fan&L1=Wall-Mount
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______________________________
Keep the whole world singing . . . .
DanG (remove the sevens)




"DonC" wrote in message
...

"Reed" wrote in message
...
DonC wrote:
Hi all,

In every house I've owned, until now, I've installed a
whole-house fan. They significantly reduce AC costs and make
for comfortable living. Alas, that was while I lived in
Michigan in houses that had attics. My typical unit included
a twist timer and variable speed motor.

Now we live in southeastern AZ in a condo with a flat built-up
roof so a typical attic unit won't work. But we still have
frequent cool nights that would we could benefit from.

Anybody here have any experience with WH fans in a similar
setting? My research so far has been disappointing -- no
variable speed fans and fewer available units : (

Thanks



Being in AZ I would consider a swamp (evaporative) cooler. A
downdraft model would easily install on a flat roof, and give
you cooling when needed, not just at night. I'll bet most of
your neighbors have one, (or A/C).

Yes we have AC. Some -- but closer to a "few" rather than
most -- have swamp coolers but they're simply a form of air
cooling limited to about 20 degrees of cooling. When temperature
get over 100, 20 degrees isn't enough.

But we're talking about a different animal here. A WH fan
"moves" existing cool air supplementing AC at a much, much
cheaper cost.