Re: Cooling attic (and home) by spraying water on roof (shingles) - good/bad?

[Some Guy <Some@xxxxxxx>]

Dll wrote:

> The readout doesn't mean anything.  I'd bet you're getting 2 C
> max accuracy.

I'm satisfied that when I bring that particular unit (with it's
internal and external transducer) along with several other (different)
units together in the same place, and see them display a temperature
within 1 degree (F) of each other, that there's little chance that
they're all out of whack by the same amount.

> Pretty scientific test you had going there...not!

My hypothesis was that spraying water on the roof would cause a
decrease in attic air temperature.

My temp display before applying the spray was showing 120+ degrees
(f).  Within 1/2 hour of applying the spray the temp went to 100
degrees and leveled off to about 98 degrees after an hour.

This was scientific in that

- I had reasonable confidence in my measurement device
- I varied only 1 parameter during the study
- there were no other variables that could have affected the
  results (like a change in outside temp, cloud cover, etc)

During the entire time the roof-mounted exhaust fan was running.

> > This is with an attic fan going.
>
> Vent fans are tried and true energy savers.

I don't know what the temp would have been without the spray and
without the fan running, but I agree that a vent fan (combined with
proper soffit ventilation) is absolutely necessary to prolong shingle
life and reduce the heat load to the house.