Attic heat project designed from the bottom up

[Exeric]

It's easy for me to forget that this is still just an experiment. It's a risky venture in that if it doesn't succeed then it will be a lot of work for nothing. The only thing that makes me OK with that is it will be documented here and the larger society can profit from it, including all of you folks. You'll know better what does not work if this does not work. And you will also know better what roof area per inhabited space and what climate is required if it does work. But failure is only helpful to others when it is documented and publicized enough that others working in any given field know about it. Enough said.

Phase 1 is done - building the heat collecting system and recording the temperatures. With this latest cold snap I now know what to expect in terms of roof temperatures in the very coldest part of winter in this climate. It's been above average temps for most of the winter until the last three days. Three days ago it was 16 degrees below the 54 degree average high for this time of winter and the high never got above 38F. Weather was overcast and the roof temp never got above 50F. Yesterday was a few degrees warmer, clearer, but windy and the roof temp got to 68F. Not quite useable for what I want. Today was the real thing: eight degrees below normal high at 46F but clear and no wind. The roof got to 80F, and it stayed above 75F for 3.5 hours. So today was the threshold day for useability of roof heating for me. So it makes me very happy that a good solar day in the coldest part of winter "might" be useable. So far I've recorded only about 4 or 5 days when there was no useable high temperatures, all when its either too cold, too wet, or a combination of windy and dense overcast. Overcast or windy alone does not seem to preclude useable roof temperatures.



It actually got a little warmer than that 44F shown, but that 80.4F roof temp was the highest reading of the day.