How necessary is air conditioning in an ICF house with decent shade and roof overhangs?
Oh man, where do I start… I’m building a daylight basement 2700 sq ft icf house climate 4c close to Portland Oregon which will be my full time job. Since I will be available for a lot of the labor and details, I originally envisioned doing radiant floor since I’d be able to lay the pipe etc and save on some of the high labor costs associated with it.
Obviously the downside with radiant is no a/c. I grew up in a 70’s daylight basement house about 800 feet away with 2×4 walls and who knows what for insulation. It was heavily shaded and up until a few years ago, never had a/c until some trees needed to be removed. In the summer hot streaks we opened windows at night and closed in morning and it was tolerable. So I went from there to a cookie cutter house with a/c and no shade so those are the only two comparables I have to go by.
I’ve been researching some hrv’s and a couple have a nice summer bypass feature where it sees what the temp is outside and bypasses the core to bring in cooler fresh air. When I saw that I thought maybe I could get away with radiant floor and use the hrv summer bypass to cool down at night.
My manual j says house will be around 26k btu for heating and 21 for cooling. I planned to do a ceiling fan in great room and one in master. The downstairs to the house I grew up in never got warm during heat waves and I have a feeling my house will obviously do better with more insulation and air sealing details so I kind of feel like I may only need one mini split upstairs. House is rectangular shaped and open concept.
Obviously with icf I don’t want to mess up and wish I had done a/c because changing things down the road is going to be a bear.
I added pic of house site, the ol’ toyota is about where garage will be and house will sit to the right. I’d guess maybe 3 hours a day in the summer I’m in full sun. Trying to convey as much info as possible, thanks for reading!
GBA Detail Library
A collection of one thousand construction details organized by climate and house part