On Mon, 07 Feb 2005 22:02:05 GMT, 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.

If you've got decent wind, windows and draft can do a very good job
without power.


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

Look at options for heat exchangers, and see what gets you the right
number of changes of air per unit of time. I forget how many changes
of air you're supposed to have per day to have good ventilation, but it's
a surprisingly high number.

It also might help if you say what climate you live in.