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[Cabo]

I agree with Constable.  I have a detached shop with radiant and never have had any anti-freeze.  This will be the 8th season and never had any problems.  Once it's up to temp (55-58) it really doesn't take much to maintain.

[cartod]

Heat goes all-ways ...did I read rite that u have no insulation under the slab?...that's to bad ...turn the heat on/fill her up ,u can shut it down like the others have said, u will luv it . I had r heat in my last place and then stant fin on the 2up stairs floors it worked great ...just like I had the whole house sitting on the back bunker/ hot plate. It does rise as all heat rises..them shimmers rising off the black top hwy  ...they are there...and its rising ain't it !

Sorry, start all the threads you want but you are misinforming people.  Heat does not rise, hot air molecules do.   

Radiant heat is not for everybody
http://www.tesmar.com/html/radiant_floors_vs_radiant_ceilings.html

[willieG]

i would never doubt an expert but I have questions...if I put ceiling heat in my basement I have a hard time believing my concrete floor will ever feel warm on my bare feed..and I wonder would I have to insulate the foor above the heat pipes in order not for half my btu escaping into the upstairs ?

I will agree in floor heat needs to be figured closely and floor covering play a huge part in it. is it a good idea or not?  for me my ceramic tile in my basement is always warm on the feet and the whole room. whether the heat is rising or moisture molecules are being heated and moving I don't know, but I do know if I turn the infloor heat off not only my feet get cold but my nose does too so somehow that heat in the pipes in the floor is getting to the whole room, in what form I don't know but if I was ever to build a new house I would have no blower to move heat, it would be in floor and radiant baseboard...clean, quiet and I think cheaper to operate once the initial cost of installing was over. I might even consider in ceiling if it was explained to me by an expert or I read a lot of information on it.

[cartod]

Bottom line, if your basement is finished and you use it by all means go radiant heat.   If you are heating your unfinished basement with radiant floors and expect the heat to travel efficiently all over the main and second floor then it becomes inefficient, not to mention in my case heating a 3,000 sq ft basement for nothing (the plate heat exchanger keeps it plenty warm).   Sure the home will eventually be warm but the basement will be 90 degrees and you will have gone thru cords of wood. 

The heat in the basement slab will not even transfer efficiently to your basement walls if your floors have rubber expansion around the perimeter (reccomended) and your exterior basement walls aren't insulated underground.

My ranch home is 7500 sq ft.  3000' basement, 3400' main floor and 1100' second floor bonus room. The main floor and the second floor have the water heat exchangers in the furnaces, and the basement is radiant.  All heated with a boiler (either indoor gas, or outdoor heatmaster 10,000e).   I have 6" insulated walls and 11" insulation in ceiling. 

We keep the main floor at 68* using the main floor air ducted furnace.  The second floor isn't used unless we have company so that furnace is set at 57*.   The basement stays around 64* because it's underground mostly and all of the water running through the pipes and plate heat exchanger becomes radiant heat.   

If I turn off the main floor furnace and try to heat with the radiant floor basement it doesn't work because in order to transfer that type of heat (radiant) up to the main floor ive got to get my slab up to at least 85* and the wood consumption almost doubles (now I'm heating 2 times as much house).  Not to mention the furnace isn't running so I need to turn the blower on to get air cleaner and the humidifier working. 

Radiant heat is not for all rooms/homes. 

If I were to get a redo I would have put radiant heat on the main floor (basement ceiling) and basement floor. 

[slimjim]

Approximately 80% of heat loss on radiant slab heating is in the perimeter walls.

[atvalaska]

I have to add that the hot air molecules from my slab heat are keeping my 3rd floor at 44+degs

[cartod]

I have to add that the hot air molecules from my slab heat are keeping my 3rd floor at 44+degs

 

[willieG]

at one time (maybe when heating oil was 20 cents a gallon) the "experts" said insulating your basement slab was a waste of money as the ground temp under there would never be below about 50 degrees....imagine that today. Hell, we worry about 100 feet of insulated  line coming from the boiler losing 1 degree now! just think if you had 5 or 600 feet in the ground under you slab with no insulation?

from what I read now, slabs should have a min 2 inches of good insulation under them and even up the inside wall to where your studs start (and then of coarse insulation in there)

 i think with the cost of all fuels insulation is a great investment ,especially for retrofitting projects

when  ever we decided to re-do a room in our old farm house i had the stud walls filled with foam, man, that stuff stops a draft PRONTO!

here our electric bills are skyrocketing we are averaging about 23 cents a KWH and prices are going up the end of the month again.

[mlappin]

Approximately 80% of heat loss on radiant slab heating is in the perimeter walls.

Amen.

My Father is still convinced we can take the old shop that isn’t near large enough or tall enough, tear out the old concrete, reinstall new with radiant heat in the floors and not insulate the perimeter and it will work just fine. I’ve shown him all kinds of data that says it won’t work, still won’t listen, so as of lately I tell him go right ahead, you’ve just taken over the wood cutting duty. He’s going on 68 next year that usually ends the talk of that foolishness. But…he’s still convinced too much insulation is bad as it might lead to mold or radon problems.

[Cabo]

Insulating a slab both under and edge is very important.  Here in VT we are required to have 3" under and at the edge.  The edge is a PITA depending on the use of the building such as a garage (driving over it) but like Slim said earlier it is a must to have any efficiency.  We're doing an addition right now with a slab on the first floor and will have foam in the walls and ceiling. The clients know it will be tighter then the main but don't understand how much tighter.  I've told them as soon a they walk into that wing it will be like walking out of cooler and into the sun.  Radiant and foam are awesome (if done right).

[schoppy]

No need to split hairs. In floor heat does transfer the heat in the lines to the slab and then to the air at it's surface which then rises and cools as it does so. The beauty of in floor heat is that the area where you work or live, 5 to 6 feet off the floor is maintained at the temperature needed and the unused area near the ceiling, especially in tall buildings, will be cooler.

I can't imagine not putting antifreeze in garages or shops with overhead doors. If doors are accidentally left open, a pump were to fail or the boiler itself goes down for any reason you would be looking at catastrophic results which could have been prevented for a small cost.

For in floor heat, insulate-insulate-insulate, especially the perimeter as Slim pointed out where the worst heat lost can occur. Also for overhead doors with connecting approaches the thermal barrier between heated and non-heated areas is critical to prevent thermal transfer to the outside approach.

You will use more wood but it may not be that much depending on the temperature you keep the basement in floor area at. You didn't say if that additional in floor area will have it's own T-stat or not? It should.