Gary wrote in message ...
N. Thornton wrote:

Our current whole house fan is in the hall ceiling just outside the
bedroom, and we often run it on low speed at night on a timer, set to
turn off around 2am or so. The noise is kind of a low frequency
rumble that is not very loud, and does not keep anyone awake. But, I
suppose this could vary from brand to brand.

The fan is a 30 inches in diameter, and is belt driven through a step
down pulley -- not sure what the final rpm is, but you can see the
individual blades turning on low speed. If you are concerned about
the noise, I would be sure to get one with two (or more) speeds.
I think the price was about $150ish.

this really confirms my brief thought to use a ceiling fan and make a
thin flexible plywood cowl for it. Mount the fan on the roof rather
than ceiling, with an extended drop rod. This would deal with the
noise issue, provide sufficient air shift, come with 3 speed settings,
and be cheap too.


Some of the WHFs are fairly awesome on the highest speed -- the one we
had in our last house would pull the drapes in at a 30 deg angle on
several windows :-) -- good for a quick cool down.

I bet! I had a 1.4kW one once, wish I still had it. Sadly I dont. It
could turn an oven into a cold wind tunnel in seconds. A bit too much
really.


Thats my #1 concern here. A WHF will move air through the already
coolest parts of the house, but not through the rooms where cooling is
needed most. Not sure how to address that. Would still be a benefit
though, and much less cost than multiple fans.

You can control which rooms gets cooled by just opening windows in the
rooms you want cooled. To get the flow balanced the way you want it
between the different rooms, you may have to close the windows in some
of the rooms part way (usually the rooms closest to the fan). Overall
we find it to be a pretty flexible system.

of course - so simple but I didnt think of it. Thank you. Much of the
air flow will have to negotiate closed doors, but several in parallel
should provide at least some airflow I hope. I'm not real convinced
though.


Although, if you have a
good place to locate a high capacity window exhaust fan, I don't see
why that shouldn't do the same thing. I think that a good window fan
location would be one that can pull air through other open windows
throughout the house, and in a location where you don't mind a fairly
high velocity of exiting air.

I think that would probably be too noisy. Also be more expensive on
wiring (with channelling), and look ugly. In terms of cooling function
it would be almost ideal, but.

Don't overlook the fact that if you use a WHF, you will have to
provide an exit vent in the attic. Normal attic venting does not
provide enough area.

of course. There is no attic venting at present. My bigger concern
though is the doors. There is only a very small area of gap under
each, and ceilng fans are high volume low pressure. This strikes me as
the one last problem. I _dont_ want horrible metal grills in the
doors. Will think some more... perhaps slice a little off the doors.
Thanks.


Regards, NT