On Thursday, July 25, 2013 8:10:50 AM UTC-4, DerbyDad03 wrote:
Ed Pawlowski wrote:

On Thu, 25 Jul 2013 01:58:34 -0700 (PDT), Senin

wrote:



I just saw this video



http://www.youtube.com/watch?v=rhz78ukb0TY



regarding how to keep you house cooler in the summertime by cooling the

attic with a box fan.



I was wondering what you guys think of it?



Do you think it would work?



Do you think there is a fire danger with the heat/electricity in the attic?



Anything that moves the hot air out of the attic space is going to

help. This is just a cheap version of a Whole House Fan.



Whole house fans are better made, more durable, probably safer than a

$15 box fan. It will also move more air.



Good side

On a cool night it will suck in the cooler outside air and vent the

attic



Bad side

One hot day, you are sucking hot air through the house and while it

may cool the attic, it may heat the living space more than keeping

windows closed and shades drawn.



It does not reduce the humidity like an air conditioner.



Another option. Consider an attic fan that just vents the attic and

does not suck the outside air through the house. That is the best

idea when the sun is beating on the room. Use a fan built for those

uses and keep your family safer.



What kind of attic fan just vents the attic and doesn't suck outside air

into the house?



He means a regular attic fan that moves air from outside through the
attic and not through the house living space like the whole house fan
being discussed.

Like Ed said, the guy has just discovered the whole house fan.
But he has some key concepts wrong. He claimed that hot air exits
the attic via the soffits. There should be vents at the top of the
attic, eg ridge vents, gable vents, etc where hot air exits. Cooler
outside air should be coming in from the soffits. If you put in a
powerful enough fan, you could reverse the soffit vent flow, but doubt
a small box fan is going to do that.

He also says that his attic has poor insulation. Well, if that's the
case, then that is costing at least comfort in the summer, assuming there
is no AC and for sure $$ in the winter. So, why not fix that?

The main benefit from a whole house fan is not cooling the attic.
It's about drawing outside air into and throughout the whole house.
That works well if the air outside is cooler and dry. It' isn't very
effective when it's 90F and humid outside. Or even at night when it's
humid outside. I've thought about how much I could use one here in NJ
and the answer is not all that much. Mostly some days in the spring and
fall.

Also, while his concept would do something, a real whole house fan
moves a lot more air, so it would be a lot more effective in moving
air through the whole house. And obviously, all of the above is
incompatible with having the house cooled with AC.