I ordered the 24" model which is rated at 4200cfm. Do you know what yours is
rated at? My climate is eastern canada
0-85 F. What type of rubber foam exactly did you use for mounting.

wrote in message
...
We do this at our 1300 sq ft. house, we have a 24 inch fan with two
speeds, and basically use the slow speed all the time. Our fan moves
air from the garage to the attic.

During the day, we open the big garage door an inch, and turn on the
fan. This keeps the attic and garage cooler. The windows in the house
are kept closed. When the sun goes down, we close the garage door and
open the door between the garage and the house. We then open some
windows in other parts of the house to cool down the house. (We live in
a dry climate with typically 30 degree day-night temperature swings).
In HVAC terminology, this is a night cooling system. My spouse does not
really understand how to use the system to best advantage. For example,
if you want to cool the bedroom, you open the bedroom windows and close
all the other windows in the house. She just doesn't grasp that closing
windows in one room cools another room more quickly. The airflow in the
one bedroom can be pretty substantial if all the other windows are
closed. I doubt if you will need to or want to slow the fan down.

The system works well for us, except on the hottest days.

As someone else said, this is almost certainly a code violation, due to
the requirement of a 45 minute firewall between the attached garage and
the house. As soon as you prop the door open between the garage and
house you are in violation.

If you are designing a new house, build in an exhaust fan for the attic
that comes on automatically whenever the attic gets hot. You can build
in a separate fan between the house and the attic or the house and the
outside for night cooling. If you want to automate it you will need
something called a differential thermostat that compares inside and
outside temperatures. (We have an inside-outside thermometer which lets
us determine when to start night cooling). Then you would have a
separate exhaust fan for the garage. Note that window fans will also
work for night cooling of the house, but you might need more than one
fan. That is the code way, and the best way to do it.

My two cents, or maybe a dime since I actually do what you say you want
to do, practice being worth more than theory.

Richard


habbi wrote:
I am building a new house (2000 sf and probably 30000 cf with vaulted
ceilings) and want to install an exhaust fan in the attached garage. My
idea
is that it will get rid of welding smoke, saw dust etc.. but mainly I
want
it for cooling the house in the summer. Open the a window at opposite
end of
house, open window in the door between garage and turn on fan. I have no
idea what CFM to get but was thinking about an 18" model rated at 3200
cfm.
It uses a 1/3 hp motor. Can these be slowed down if to much air is
moving.
Can any motor be slowed with a speed control or are certain motors only
designed for this. I guess I could put a smaller fan blade on to reduce
flow. Thanks