On Jun 18, 7:59*pm, Red Green wrote:
z wrote :





On Jun 17, 12:08*pm, wrote:
On Jun 16, 9:01*pm, Red Green wrote:

"Joseph Meehan" wrote
innews:4856aa0b$0$30
:

* * Different areas of the world get different results and certai
nly
different vents (inlets) make for differences in results.

* * Frankly I have not found that power vents are of much if any
use.
Proper generous static venting seems to work just as well without
noise and electricity. *The worse situations I have seen is when
po
wer
vents end up disrupting the natural flow and can even increase
the temperature.

* * The real differences I have seen is poorly vented areas.

* * Overall yours does not seem to be bad.

* * If you really want to do something make sure it has inlets gr
eater
* * than
the minimum required and that thefanis not short circuiting the
natural air flow.

or sucking the AC out of the house via access, vents (stupidly)
terminating in theattic, etc.

"z" wrote in message
.
com
.
..
got a remote reading thermometer and stashed it in theatticto
see what's happening. now i'm wondering what i should expect.

normalish 50 year old ranch house, connecticut. 1500 sq feet
more or less. old central AC, not particularly powerful or
efficient. normal amount of insulation, i.e. less than would be
optimum but normal for the period. powered ventfan, mushroom
style. soffit vents, gable vents, etc.

on the wise advice proferred here last year, i upped the temp on
the thermostat for the ventfanfrom 80 degree to about 100 IIRC.

OK; so during the final months of *winter, when i had the
thermometer, there was a maximum of about 20 degrees difference
between the house and theattic.

lately, when it's warm, often 20 degrees difference, obviously
in th
e
opposite direction. during a hot spell last week, when it was
90+ outside,atticgot up to 120; house got up to 87 (AC off
during daytime).

so, is this reasonable/expected for poweredatticvent? would
bigger
fando better?- Hide quoted text -

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He doesn't say what the temp was outside during the final days of
winter, but if the temp diff between theatticand the house was only
20 deg, I hope it was not very cold outside, as that means theattic
was at about 50 deg. * *If it was cold outside, *I'd expect a much
bigger temp difference between theatticand the inside of the
house.

Probably the best thing that could be done here is to increase the
amount ofatticinsulation. * That will do a lot more to keepattic
heat out of the house than installing a biggerfan. * Plus you get
benefit not only in summer, but also with reduced heat loss in the
winter.

I also second the advice to make sure there is adequate intake
opening, ie soffit, gable, etc. * If there isn't, you not only reduce
the cooling capaciyt, but you can be sucking air from inside the
house through any gaps, openings around fixtures, etc.- Hide quoted
text -

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i was afraid you'd say something like that. is installing more
insulation as big a PIA as it looks? to make it worse, the previous
dwellers laid plywood over the joists to provide flooring for storage.
at least they didn't bother to fasten it down.
the previous dwellers laid plywood over the joists

This comment may be a whole new ballgame you know.

If the insulation was any thicker than the ceiling joists/bottom truss
chord and they put plywood over it and compressed it, they have reduced
the r-factor of your attic insulation. Insulation works because of the
air within it. Depending on how much it was crushed depends on how much
it reduced it.

Were there areas of no plywood? What's the insulation scoop there?- Hide quoted text -

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yeah, i thought of that, but as far as i can tell, the insulation just
was installed up to the top of the joists, maybe on purpose so they
could use storage space. i think i'll store my collection of valuable
antique paraffin wax sculptures and vinyl records up there.