Jackie Treehorn is planning a new home near Portland, Oregon, to be constructed with insulated concrete forms and designed with a daylight basement. He’d like to include radiant-floor heat, and because he plans on doing a lot of the work himself he hopes to reduce labor costs that typically go along with that kind of heating system.
One of his concerns is cooling. Treehorn grew up just down the road, in a 1970s house built with 2×4, questionable amounts of insulation, and no air conditioning.
“It was heavily shaded and up until a few years ago, never had AC until some trees needed to be removed,” Treehorn writes in this Q&A post. “In the summer hot streaks we opened windows at night and closed them in the morning and it was tolerable. So I went from there to a cookie-cutter house with AC and no shade so those are the only two comparables I have to go by.”
His research has led him to a type of heat-recovery ventilator with a feature that allows him to bring in cooler air in summer without going through the heat-exchanger. That might provide cooling at night. He’s also planning to install a single ductless minisplit head.
Treehorn has already done some Manual J calculations, which show the heating load will be 26,000 Btu/hour and the cooling load 21,000 Btu/hr. He’s planning on putting in a couple of ceiling fans.
“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 minisplit upstairs,” he says. “House is rectangular shaped and open concept.
“Obviously with ICF I don’t…