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Spray foam shop staying hot

before I had insulation and A/C, I ran an exhaust fan on a timer in the summer. It worked very well.

A timer is way cheaper than a differential temperature setup, and day/night temps are cyclical and predictable. I ran it 4am to 6am. It lowered building temp 10-20 degrees or so.
I'm not sure but I think that's a dry vs wet climate issue.
Around Houston bringing a bunch of damp air into the building will not have much upside.

"miserable" air coming into my space is not what I am after.... I am sure AZ has a better looking chart...
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edit: I had to know:laughing:
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The question is how long does this air space take to heat up.... Is it 30 minuets? Well that is worthless.. is it 8-10 hours... well hell the sun is already going down and it is starting to cool off.

The issue then becomes that that heat is inside the wall and it radiates back out over night.

Maybe I am dumb... but the Yeti is a unvented air space and it keeps my drink cold for a long time...

The Yeti / Thermos is a vacuum, not an air space. So you don't get convection transfer.
 
Here's some data from the likely poorly built front part of my 1987 home
The thermostat has two temps day time and night time, day 76*F starts at 7 am and night 73* starts at 9:30.
The space at 7-11? is how long it takes to warm up to the trip point of 77* (76* +1* swing)
Even this poorly built home is somewhat better than a poorly built shop, but maybe not.


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And the more poorly built rear addition.
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90* ambient temperature
Shop AC set to 75 for 36 hours prior

Outside temp on door
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Inside temp on door
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Poor boy insulation
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Looking around a radiant floor is sized similar to this door example, 20-25 BTU per SQ foot. If we reverse each of my 100 SQ ft doors heats my shop in direct sun with 2250 BTUs of heat for 5000 BTU total.

So 1/2 a ton of heating... In my shop, that's not insignificant.

That's a 1500w space heater running 10+ hours
 
The problem is that air is still circulating along those slats of the door, so the air is heating up and flowing into the space.
I'm well aware of the problems with these doors, they are really only barriers, doors is too good of a description.
 
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