|Dave has provided below a great record of attic temperatures for his
house in southeastern VA, as well as some good observations about using
attic heat and a thermal image of the attic ceiling.
This is part of the section on using solar heat from attics...
Thanks very much to Dave for providing this excellent material!
Here's some more information on the attic to help in understanding the temperature data:
I asked Dave: Has the data convinced you that its worthwhile to use the attic heat?
As far as usable heat... no.
What I've found is that attic vents itself quite well. During the summer months when the outside temperature gets to 90 or so the temperature may get to 110 in the attic (this is at the 6' level where the sensor is), but even when it gets over 100 outside, the attic doesn't seem to heat up much more than 110-112.
During the winter the attic temp during the day seems to track right along with the outside temp + 5 degrees or so. In the winter evenings the attic temp will cool off but rarely does it ever drop below freezing even when it's in the 10's outside.
This first plot shows the whole year, and the following plots show 2 months periods to show more detail.
August - September 2010
October - November 2010
December 2010 - January 2011
February - March 2011
April -- June 11, 2011
This is a thermal picture of the roof from inside the attic taken in March at ~noon when the outside temp was 50 and the attic temp was 55.
June 11, 2011
Dave also has a great blog on energy saving and energy monitoring...
Gary June 12, 2011