Writing from Texas, Xeven says he and his wife are planning their new house, and because of the high price of lumber they are considering insulated concrete forms instead of conventional stick framing.
“As such, we have also been looking into radiation heating/cooling instead of the conventional forced-air systems,” Xeven writes in this recent Q&A post. “Some people I’ve spoken with keep saying that radiant heating is not a good idea in Texas due to the thermal mass of the concrete, stating we’d basically bake ourselves out of our own house.”
Xeven, however, suspects that an ICF house would keep temperatures relatively stable.
As to radiant cooling, the biggest issue in his mind would be the possibility of condensation, a risk when humid indoor air comes into contact with a surface below the dew point. But, Xeven asks, wouldn’t ICF construction be an advantage here as well?
That’s where we begin this Q&A Spotlight.
There are cheaper options
Steve Knapp’s advice is to build what the GBA community calls a “Pretty Good House,” either with conventional materials and techniques or with ICFs. That should keep both heating and cooling loads low, but Xeven should keep his expectations realistic.
“It often seems that people want radiant heat for that toasty-toes feeling,” Knapp says. “You are not likely to get that in a tight house since the system won’t run that much (especially in Texas). With radiant cooling, you will need to be careful about managing indoor humidity levels.”
In any event, Xeven could probably save a lot of money by installing a properly sized force-air heating and cooling system, without sacrificing any comfort.
Does thermal mass matter?
ICF walls consist of inner and outer layers of rigid-foam insulation and a…