Concrete Curing
Current Wx: Temp: 65.34°F Pressure: 1010hPa Humidity: 69% Wind: 12.39mphWords: 380
I have a little FLIR camera that used to plug into iPhones through the Lightning port. Now I use it with an old iPod I keep for pretty much just this.
I took some pictures with it last night, and then again this morning. What is recorded here is the exposed concrete at the top of the wall at about 80°F. The EPS foam is obviously cooler in the blue and dark green tones. Where you see brighter green in between individual ICF blocks is likely warm water that has migrated from the concrete through capillary action. The part of the wall most distant from the camera is warmer, likely because it is radiating into a smaller space and facing a nearby wall of shale that had warmed throughout the day yesterday. The part of the wall nearest the camera has more space between it and the excavated wall, which is shale and wet clay.
Most interesting to me are the footings in bright green, the warmest part of the wall structure apart from the exposed concrete at the top. Heat is being transferred from the curing concrete to the footings below. When the backfill is eventually completed, that area will likely remain about 55°F year-round. Since there is no insulation around the footings, they are in thermal contact with the ground, and so heat that is transferred from the air above ground, through the EPS foam to the concrete, will transfer to the region of lower temperature down toward the basement and the footings, before it migrates to the interior of the house. This is "thermal lag." What isn't well characterized, to my knowledge, is the temporal dimension, i.e. how long does it take heat from outside the house to migrate inside sufficient to warm the interior.
The west end of the house will be mostly glass, so there will be a lot of solar gain, though that is mitigated to some extent by the large extended roof over the deck. When the sun is lower during winter, that roof covering will be less effective, but the solar gain will be more welcome.
We haven't tried to design a "passive house," but we do have some features of such a design.
The beat goes on...
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