Radiant floor provide enough heat?

[headrc]

Just to double check here before I move ahead .....what is the overall feeling about a radiant floor providing enough heat for a room .....first of all one that is well insulated, no windows and the radiant floor will be in the slab ....then for a room that is going to have the radiant installed between joists ....and the insulation can be considered good ...meaning very good insulation in the joists but the outside walls have blown in insulation as well as outside 1/2" insulation board under siding ...... and there are two windows in this room. Thx again, RH

 

[flyingcow]

You're in Tn...I'm in northern maine. I have radiant in only my kitchen, plan on adding on. Love it, does a very nice job. I have seen -40 below. can't imagine it not working well down in the warm south.

 

[Chris S]

we have done staple up installs that net 25 btus / s.f. Do the math- it almost always works, the occasional exception being a bath with not much floor space, or a kitchen- same deal. As for your slab- can't go wrong with all that thermal mass, but insulate under it!! Our design day is 0 degrees outside, 70 degrees inside, whats yours?

 

[WoodNotOil]

I retrofitted radiant in floor joists and it works really well. I also have baseboards/radiators on the same floor for the really cold windy days and spring/fall days that the floor is way overkill. My house is old and the walls are not well insulated though. You may be fine without it. How cold does it get in Tenn?

 

[Bob Rohr]

Probably, but a room by room heatload calc and design would assure you can make it work. It would also provide you with temperature and tube requirements.

Heat load calcs are cheap and easy, "Google" for a free online load calc program.

hr

 

[headrc]

I am a novice ....so I am going to have to educate myself (and plan to) ...on design days, heat loss calc etc. However, Tn. rarely gets below 15 degrees F ....and it does not stay there very long. Usually during our coldest days (which are only about two to three weeks max) we have around 32 degree F days and then maybe in the low 20's at night. Judging from the feedback you all have given me ...I am confident that I will be OK ...but I do plan to study it and become more educated technically before I move ahead ...Thx, RH

 

[headrc]

So it looks like my outdoor design temperature is ) degrees F .....I used a heat loss calculator and it indicated a heat loss of around 38000 btu (if I did it correctly) for the area in the house that I am considering (60 square feet) for floor joist staple up radiant. RH

 

[Nofossil]

So it looks like my outdoor design temperature is ) degrees F .....I used a heat loss calculator and it indicated a heat loss of around 38000 btu (if I did it correctly) for the area in the house that I am considering (60 square feet) for floor joist staple up radiant. RH

Hmm.... I'm assuming a typo here, but I can't figure out exactly where.

60 square feet does not compute. That's an area smaller than eight feet square. Unless you're heating a porta-potty, that doesn't seem right. And a porta-potty would be hard pressed to lose 38000 BTU per hour, even in Antarctica.

60 feet square would be a pretty big single story house (3600 square feet). That's a reasonable square footage, but a very odd footprint.

600 square feet would be really small, too, though bigger than a porta-potty.

Are you trying to heat a much larger space with 60 square feet of radiant floor?

 

[headrc]

Sorry ....yes the figure should have been 600 square feet ....whihc is the bottom floor of my farm house which I want to put radiant heat in the floor joists. RH

 

[SE Iowa]

I live in an all radiant floor heat home that has very efficient wall insulation (ceiling just blown in cellulose). My living room (18x24) is on the north end of the house above the walk out basement. It has two 3x4.5' windows on the north side and two 3x5.5' windows on the west side. We basically live on the border b/w the prairie and the midwest. It is very windy (yseterday had 60 mph gust) and temps get to -10-15F actual temps. With wind chill effects it usually will get to -50 to -70F for 1 to 3 weeks a year here. The floor has tubes embedded in gypcrete (I don't really like this stuff) and has semi-shag carpet with pad overtop. All this said, there is 1 to 2 nights per year where the floor has a struggle keeping the temp up to 70F. It catches up the next morning. I'm told that we could fix this if I would insulate under the floor in between the joist so that heat would be forced to go up, but I just haven't got around to it yet. One thing you must consider is the typr of floor covering and placement of the house. From what you said about where you live, etc, I wouldn't even worry about it. This is the only room we have trouble with d/t its location, size, and floor covering.