My family is planning a building a highly insulated (likely SIPs) second home in the mountains of colorado. I'm doing a good deal of the research myself. While I'm strongly leaning towards radiant floors for its many pluses, I seem to have run into a potential downside that I can't find much discussion of anywhere.

I was reading a Daniel Chrias book (the solar house) and he suggested one of the cons he found with radiant floors is that they transfer heat only to objects in their direct path. He states he often became uncomfortably chilly when sitting or curled up on a couch. An article by Tom Bacc on radiant heat suggests much of the same.

Can people speak to experiencing or not experiencing this? I'm particualry worried about my Dad who has less than stellar circulation and suffers from perptually cold hands and feet. These are the only two places I've seen this discussed, but its enough to scuttle my radaint floor plans. Does anyone have any thoughts on this?

thanks

I am sitting here with my morning coffee and reading your post. My feet are not on the floor and I am perfectly warm.

We have radiant heat. I have never had that problem. We actually keep the whole house several degrees cooler that we would with forced air.
Here at home it is set at 68. In a little while I will head to my office at work and it will need to be at 71 or 72 to keep me warm.

I have a house at 8,900' in Colorado. The entire lower level is heated via radiant floors. It is the most comfortable area in the house! Now I have lived in places that used electric radiant(it was in the ceiling - on top of the drywall) and yes, you could notice the difference. Table tops warm, floors cold. But the radiant floor in my house keeps the lower level very comfortable.

that's not a radiant ceiling issue. that's an on/off control strategy issue; the radiant is not consistently operating to keep all spaces warm.

Couches right next to large windows might have comfort issues; this depends on the quality of window more than anything. Generally I only hear of issues there in "nooks" with 3 sides of glass or next to major picture windows. Radiant is great, but sitting right next to a huge "cold radiant" plane (pane? er..) sets up a fight.

Beyond that, any kind of responsive control (say, outdoor reset, modulated output of any kind really) should allow all objects in the space to heat up nicely and stay comfortable.