Am thinking that I'd like to put a vent fan in my attic this year before
it gets too hot, to improve attic ventilation. House was built in late
40's and has unusual roof with no soffits, end of roof is almost even
with siding. Only ventilation is two vents at each end of the side
walls, just under the peak of the roof. Front door of house faces east,
so peak of roof runs north-south.

Question is, which end of the house would be preferred to mount the fan,
if any, and should it blow or suck?

nate

--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel

On Apr 1, 8:42*pm, Nate Nagel wrote:
Am thinking that I'd like to put a vent fan in my attic this year before
it gets too hot, to improve attic ventilation. *House was built in late
40's and has unusual roof with no soffits, end of roof is almost even
with siding. *Only ventilation is two vents at each end of the side
walls, just under the peak of the roof. *Front door of house faces east,
so peak of roof runs north-south.

Question is, which end of the house would be preferred to mount the fan,
if any, and should it blow or suck?

nate

--
replace "roosters" with "cox" to reply.http://members.cox.net/njnagel

Put the "attic exhaust" fan on the south side, it will pull in cooler
air from the north side of the house than if the exhaust fan was on
the north side pulling air in from the south side as the south side of
the house faces the sun and heats up the air which then would rise and
get sucked into the attic

On Apr 1, 8:42*pm, Nate Nagel wrote:
Am thinking that I'd like to put a vent fan in my attic this year before
it gets too hot, to improve attic ventilation. *House was built in late
40's and has unusual roof with no soffits, end of roof is almost even
with siding. *Only ventilation is two vents at each end of the side
walls, just under the peak of the roof. *Front door of house faces east,
so peak of roof runs north-south.

Question is, which end of the house would be preferred to mount the fan,
if any, and should it blow or suck?

snip


Both.
Wet your forefinger and hold it up like pro golfers do and you will
find the prevailing winds are from the Southeast. Therefore, use two
fans, suction on the Southerly end and blowing outward on the
Northerly end.

Joe

On Thu, 1 Apr 2010 20:16:44 -0700 (PDT), "hr(bob) "
wrote:

On Apr 1, 8:42*pm, Nate Nagel wrote:
Am thinking that I'd like to put a vent fan in my attic this year before
it gets too hot, to improve attic ventilation. *House was built in late
40's and has unusual roof with no soffits, end of roof is almost even
with siding. *Only ventilation is two vents at each end of the side
walls, just under the peak of the roof. *Front door of house faces east,
so peak of roof runs north-south.

Question is, which end of the house would be preferred to mount the fan,
if any, and should it blow or suck?

nate

--
replace "roosters" with "cox" to reply.http://members.cox.net/njnagel

Put the "attic exhaust" fan on the south side, it will pull in cooler
air from the north side of the house than if the exhaust fan was on
the north side pulling air in from the south side as the south side of
the house faces the sun and heats up the air which then would rise and
get sucked into the attic

I was going to say leeward, to be helped and not hindered by the
prevailing breeze, but I think your argument is stronger. Unless
there is a lot of prevailing breeze.

Nate, you may need more ventilation on the opposite end. You can't
squeeze blood from a turnip, whatever that means. OTOH, you can do
this part first and then check.

On Apr 1, 8:42*pm, Nate Nagel wrote:
Am thinking that I'd like to put a vent fan in my attic this year before
it gets too hot, to improve attic ventilation. *House was built in late
40's and has unusual roof with no soffits, end of roof is almost even
with siding. *Only ventilation is two vents at each end of the side
walls, just under the peak of the roof. *Front door of house faces east,
so peak of roof runs north-south.

Question is, which end of the house would be preferred to mount the fan,
if any, and should it blow or suck?

nate

--
replace "roosters" with "cox" to reply.http://members.cox.net/njnagel

It should be mounted to suck air out of the attic and blow it
outside. Make sure the vent on the other end is big enough to
accommodate the fan's airflow - the instructions should indicate how
many square feet of venting you need. As for which end, if it were me
I would probably be guided by aesthetic considerations - mount it
wherever you will see/hear it less. I agree with the poster who
suggested the air on the north side of the house will be cooler, but I
suspect the ultimate difference in the attic temperature would be
minor. -- H

Joe wrote:
On Apr 1, 8:42 pm, Nate Nagel wrote:
Am thinking that I'd like to put a vent fan in my attic this year
before it gets too hot, to improve attic ventilation. House was
built in late 40's and has unusual roof with no soffits, end of roof
is almost even with siding. Only ventilation is two vents at each
end of the side walls, just under the peak of the roof. Front door
of house faces east, so peak of roof runs north-south.

Question is, which end of the house would be preferred to mount the
fan, if any, and should it blow or suck?

snip


Both.
Wet your forefinger and hold it up like pro golfers do and you will
find the prevailing winds are from the Southeast. Therefore, use two
fans, suction on the Southerly end and blowing outward on the
Northerly end.

So, prevailing winds are always from the southeast? Everywhere in the world? Or
do you know where the OP lives?

Joe wrote:
On Apr 1, 8:42 pm, Nate Nagel wrote:
Am thinking that I'd like to put a vent fan in my attic this year before
it gets too hot, to improve attic ventilation. House was built in late
40's and has unusual roof with no soffits, end of roof is almost even
with siding. Only ventilation is two vents at each end of the side
walls, just under the peak of the roof. Front door of house faces east,
so peak of roof runs north-south.

Question is, which end of the house would be preferred to mount the fan,
if any, and should it blow or suck?

snip


Both.
Wet your forefinger and hold it up like pro golfers do and you will
find the prevailing winds are from the Southeast. Therefore, use two
fans, suction on the Southerly end and blowing outward on the
Northerly end.

Joe

Hmm, maybe I need a new finger? My prevailing winds are from the south
west.

"Heathcliff" wrote in message
...
On Apr 1, 8:42 pm, Nate Nagel wrote:
Am thinking that I'd like to put a vent fan in my attic this year before
it gets too hot, to improve attic ventilation. House was built in late
40's and has unusual roof with no soffits, end of roof is almost even
with siding. Only ventilation is two vents at each end of the side
walls, just under the peak of the roof. Front door of house faces east,
so peak of roof runs north-south.

Question is, which end of the house would be preferred to mount the fan,
if any, and should it blow or suck?

nate

Blows to outside. Mount it on the end that is easiest to wire.

Nate Nagel wrote:
Am thinking that I'd like to put a vent fan in my attic this year before
it gets too hot, to improve attic ventilation. House was built in late
40's and has unusual roof with no soffits, end of roof is almost even
with siding. Only ventilation is two vents at each end of the side
walls, just under the peak of the roof. Front door of house faces east,
so peak of roof runs north-south.

Question is, which end of the house would be preferred to mount the fan,
if any, and should it blow or suck?

nate


The fan should take air OUT of the attic, and if it were me, i'd put it
in the north end. The prevailing wind is *generally* from the south, so
if the fan were in the south gable, it would be working against the wind
some of the time. Also, make sure you have an adequate venting to
accommodate the fan capacity.

Bob F wrote:
Joe wrote:
On Apr 1, 8:42 pm, Nate Nagel wrote:
Am thinking that I'd like to put a vent fan in my attic this year
before it gets too hot, to improve attic ventilation. House was
built in late 40's and has unusual roof with no soffits, end of roof
is almost even with siding. Only ventilation is two vents at each
end of the side walls, just under the peak of the roof. Front door
of house faces east, so peak of roof runs north-south.

Question is, which end of the house would be preferred to mount the
fan, if any, and should it blow or suck?
snip

Both.
Wet your forefinger and hold it up like pro golfers do and you will
find the prevailing winds are from the Southeast. Therefore, use two
fans, suction on the Southerly end and blowing outward on the
Northerly end.

So, prevailing winds are always from the southeast? Everywhere in the world? Or
do you know where the OP lives?


Well, since it's Nate, and he's on cox dot net it's pretty safe to
think he's in north america. and yes, the prevailing wind is from the
south in NA.

On 04/04/2010 09:47 AM, Steve Barker wrote:
Bob F wrote:
Joe wrote:
On Apr 1, 8:42 pm, Nate Nagel wrote:
Am thinking that I'd like to put a vent fan in my attic this year
before it gets too hot, to improve attic ventilation. House was
built in late 40's and has unusual roof with no soffits, end of roof
is almost even with siding. Only ventilation is two vents at each
end of the side walls, just under the peak of the roof. Front door
of house faces east, so peak of roof runs north-south.

Question is, which end of the house would be preferred to mount the
fan, if any, and should it blow or suck?
snip

Both.
Wet your forefinger and hold it up like pro golfers do and you will
find the prevailing winds are from the Southeast. Therefore, use two
fans, suction on the Southerly end and blowing outward on the
Northerly end.

So, prevailing winds are always from the southeast? Everywhere in the
world? Or do you know where the OP lives?


Well, since it's Nate, and he's on cox dot net it's pretty safe to think
he's in north america. and yes, the prevailing wind is from the south in
NA.


In fact I am on the east coast, DC area to be precise. So yes, at least
a lot of our weather comes up from the south. It would be easier to
mount the fan on the north side, completely independent of any other
considerations (south side has a chimney)

I'm certain that the ventilation is *not* "adequate" by modern
standards, hence my consideration of adding the fan. I would add a
ridge vent, but the roof is metal and in good condition.

nate

--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel

Steve Barker wrote:

-snip-


Well, since it's Nate, and he's on cox dot net it's pretty safe to
think he's in north america. and yes, the prevailing wind is from the
south in NA.

Poppycock. I'm in NA & *my* prevailing wind is from the WSW.

I'm on the west bank of a sloping valley that runs north/south. Folks
at the top of the hill or other bank probably have a different
prevailing wind.

And 'prevailing' winds can come from different directions different
times of year.

Search this pdf for 'prevailing' to see a little about NY's winds--
including mention of how some sites have 2 prevailing wind directions
90 degrees apart.

Jim

oops - forgot the link
On Sun, 04 Apr 2010 10:51:31 -0400, Jim Elbrecht
wrote:

-snip-

Search this pdf for 'prevailing' to see a little about NY's winds--
including mention of how some sites have 2 prevailing wind directions
90 degrees apart.

http://www.powernaturally.org/progra...werproject.pdf


Ran across this one when I was looking for that one again-
http://nysc.eas.cornell.edu/climate_of_ny.html
from that page-
"The prevailing wind is generally from the west in New York State"

Jim