Stupid question probably, but I have never lived in a cold climate before. Built an ICF house. Hurd windows. Turn the heat off at night, gets into the mid 50’s. If it gets near zero outside overnight, I will have frost on the bottom inside of the windows. North side only. Is this standard? I’m in southwest Colorado.
Thanks, John
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That is from humid air and cool surfaces.
It is more common in the first year or so after a house is built because materials are still drying and off-gassing moisture, concrete especially.
Leaving heat on would make the air more capable of keeping moisture in suspension instead of looking for a place to dump it. With the same amt of moisture in the air, as that air cools, the relative humidity goes higher and the air is less capable of holding onto it at the same time the window surfaces are getting colder.
There have been studies comparing the amt of BTUs used to maintain a temperature vs the amt of BTUs needed to raise the volumn of air in a house back up to comfort level each day.
There are variables, but in general, with a well insulated house and eficient heating system, the rule of thumb is that you need to leave the heat turned down for three days to save enough to overcome the "inertia" and save any energy.
So turn it down when you go away for the weekend, but leave it comfortable overnight.
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With an ICF house I am surprised that he is getting that much tempature drop, unless he is only keeping it around 60 during the day..
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
I'm a bit disappointed myself. We have a fair amount of glass, not ridiculous, and that seems to be the weak link. We set the thermostat at 65 during the day and 54 at night. Furnace will only turn on during the really cold nights, usually house will stay above 56. Found out propane is expensive. Not completely sold on the ICF but I have no comparison for energy efficiency.John
ICF is great. What percent wall area is glass?I noticed what Bill did too.
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Roughly 10 per cent of wall area is glass. 2050 feet of living space. Ceilings are 9"4" with two rooms vaulted to about 12'. Attic has 15" of blown in. Raised floor with about 85% tile. Not sure if that is part of the problem. Should be cool in summer. Crawl space is about 50 degrees with ICF walls. No sure what else I could have done except foam in the attic. Any opinion?Thanks, John
What material for the windows? Metal will almost always have inside frost, even in warmer areas.
Overall, sounds pretty good from here. I'm thinking this is fairly new still and concrete giving off moisture.Danno's idea sounded pretty good.crawl maintaining 50° shows the ICFS are insulating fine,What direction does this window wall face?
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Maybe get insulating drapes, or snap in place, magnetic or Velcroed insulating panels to put over the inside of the windows at night?