From: grande@cbnewsd.cb.att.com (brad.l.grande)
Subject: Re: Whole-House Fan Choice is Not a Breeze
Organization: AT&T
Distribution: na
Date: Wed, 9 Sep 1992 18:55:28 GMT

In article <jzrn+h+.greg@netcom.com>, greg@netcom.com (Greg Bullough) writes:
> In article <1992Sep8.180818.29875@cbnewsd.cb.att.com> grande@cbnewsd.cb.att.com (brad.l.grande) writes:
> >In article <f_nn=+b.greg@netcom.com>, greg@netcom.com (Greg Bullough) writes:
> >>  
> >>   3. To pump air which is cooler than the ambient attic temperature
> >>      into the attic, thus improving house cooling.
> >>  
> >> In my experience (3) is very important. My whole house fan has
> >> cut the time the gable fan runs by a great deal.
> >
> >An article in Consumer Reports on house cooling a couple of years ago discussed
> >item 3 above and suggested that if you had sufficient insulation (don't remember
> >the exact amount but I do recall that it was what you would find in any post
> >1970's energy crisis built home) that heat infiltration through the ceiling
> >was minimal and the whole house fan would not have an effect on this aspect.
>  
> They're just plain wrong. I can certainly feel the effect of the attic
> re-heating the house when only window fans are used to bring the temperature
> down. And my house was built in 1983. With heavy ceiling insulation. But
> the attic is small and reaches scorching temperatures.

I am not one to stand up for CU, but I have a 1 1/2 story (upstairs ceilings
AND walls exposed to attic) and have 16" in the ceiling and 6" of insulation
in the walls.  The only heat I can feel radiating in from the attic is through
the access door.  Since you are talking about using window fans and heat raises,
could it possibly be that hot air in the house is raising above the windows and
not getting exhausted?  (Sticking your hand into an area of warmer air would
feel like something was radiating the heat)

>  
> >The article went on to suggest that if you did not have sufficient insulation
> >that it would be cheaper to add insulation than to add a whole house fan.  It
> >also said that power attic ventilators were not effective if the insullation
> >was adequate and therefore they were not an effective investment.
>  
> Again, I, and my neighbors, have found that a gable fan does, indeed, help
> control the overall temperature of the house, especially in a three-day
> heat wave. 
>  
I don't know if you or your neighbors have whole house fans, bathroom fans that
exhaust into the attic, or leaky attic access doors, but a gable fan could pull
heat that has built up near the ceiling out of the house through any of these
places.
>
> CU is a crock on this one. There are other reasons to keep the attic cool,
> as well, such as keeping the structure and the roof healthy.
>
Agreed, however, I have read in several different places that if your attic has
sufficient venting, then a power ventalator is ineffective.
> 
>  
> Then again, I sometimes run the whole-house fan in the winter, just to
> freshen up the house :-)
I wish I could do this, but being here in Illinausea, I cover up my whole
house fan with insulation during the cold months.
>  
> Greg

Brad Grande	WB0OYX
Another bike riding beer brewing kite flying amateur radio operator who
	still likes CD's!

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