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Old 08-31-12, 01:58 AM   #12
opiesche
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Join Date: Jul 2012
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Just a quick update on the temperatures. We're experiencing an unusually cool late summer - it's not even quite September yet, and outside temps are already at 55F around 10:00pm. Interior is 73F at that time, and between then and about 1am go down to roughly 72.5F, with the exterior at about 53.


So, in 3 hours with a dT of -2F exterior, I'm seeing an interior dT -0.5F with a total dT of 20F between exterior and interior.
So, that tells me that, roughly for every degree difference between interior and exterior, I'm seeing 0.015F of decrease of interior temperature per hour.

In the winter, if we're assuming 35F at night, the dT exterior-interior would be about 35F, and assuming a linear relationship (not sure if it is, more data will tell), I should expect a decrease of 0.53F per hour in the house, or the same as raising the temperature by 0.53F per hour to keep it at 70.

Now, that's only if the relationship between the exterior-interior dT and the heat loss is really a linear equation. Anyone know if that's actually the case?

Crawlspace insulation will of course change that equation again, and it'll also be interesting to see how effective it is once installed. I've got a few months of data logging ahead of me (there's something I could put my Raspberry Pi to good use for!), but 0.53F per hour sounds like a piece of cake for a 980sqft radiator
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