Who here has a hydronic radiant heat system in the concrete floor of their cabin? What do you think of it and was it worth it?
Thanks Mark
I installed radiant tubing in my basement slab, but haven't gotten to the point I can use it. It was cheaper to install before the slab was pored than trying to retrofit. My neighbor use it and loves it. I must say it is nice to be able to walk around on a warm floor.
I installed it in my slab and am very close, finally, to using it for the first time since I built in 2005.
With radiant, it seems like if you ask five people the best way to install it, you'll get ten answers.
I have recently come across some information on design of a radiant system which I haven't seen before. These concern the depth of the tubing in the slab and how that will effect efficiency, and the use of plates and insulation in an underfloor installation.
www.inspect-ny.com/heat/Radiant-Slab-Heat-Mistakes.htm
http://findarticles.com/p/articles/mi_m0BPR/is_6_20/ai_102862289/pg_1
From
http://www.radiantmax.com/r-underfloor.htm
l I found this "data" concerning the use of aluminum plates and insulation in an installation under a wood subfloor:
Floor Output at 140°F Inlet Temperature: Output in Btu/hr/sq. ft
No plates, 5/8" air gap
23.5
No plates, 2" air gap 26.2
Plates, 2" air gap 42.0
Plates, 5/8" air gap 46.3
Average test results at steady state with a 140°F inlet water temperature
From the theories of design I heard when I built, a radiant in a slab could be designed either as a (relatively) fast reacting source of heat (a well insulated slab) *or* as a storage form of heat (less insulated slab). If you want storage capabilities so that the house will stay above freezing for a few days to a week without keeping automated sources of heat running, then a slab with less insulation under it will do this because heat is supposed to be stored in the earth under the slab. I figured on using the radiant as a secondary heat source with wood heat as the primary, and wanted a way to keep the house a bit warmer if I am gone for a few days, so built it without insulation underneath. The perimeter of the building is well insulated to a depth of 4 feet and the slab is isolated from the perimeter wall by being floated with insulation separating the two. When I start it up, I'll post back after I see how long it takes to reach a steady state. I'm guessing I'll see it stabilize over one to two weeks.
Tom
Mother Earth News has a extensive article on solar heating using radiant heat this month. Their idea is to contruct a shed that has one side facing south and having a solar collection system incorperated in the contruction of the shed. The heated water is held in a tank and then circulated thru the coil in the slab or wood floor. I think that you can look up their articles on line for more info.