Solar heated garage floor

[Sageair]

I'm getting ready to build a new garage that I want to heat with hot water piped thru the floor. Any hints would be appreciated.

 

[bmoeller]

http://search.msn.com/results.aspx?srch=105&FORM=AS5&q=radiant+floor+heating



Have no experiance with it. Sounds like a great idea though. Have seen it used quite a bit on the "This Old House" TV show.

 

[MFalkinham]

I think heated concrete floors are a great idea, and wish my workshop had one. I'm not sure of the solar part of the equation, though. Up here in Wisconsin I'd probably need an outdoor wood furnace or natural gas boiler to keep the water temp hot enough. Also check out geothermal heating of the water. http://www.eere.energy.gov/geothermal/ghp_buildings.html



- Mike

 

[Glen]

I have heated floors in my living room--marble over concrete--and in the kitchen--Pergo over aluminum heat spreaders. The water is heated by a wood-fired boiler. I also have a gas-fired boiler for backup.



It is important to use the special plastic pipe--cross-linked polyethylene with an oxygen barrier, PEX--made for hot water systems. It is expensive--I paid 0. 85 a foot for 1/2 inch--but steel, black iron, copper and other plastics will fail in service. It is not good to have broken pipe buried in concrete.

 

[MMiller]

Living in the midwest I would like to run the pipes in the floor, and use a corn burner to heat the water. Right now corn price is good, but usually you can buy pretty cheap in the off season. It is nice because the heated floor heats up everything in the shop, tools, benchs, instead of just the air. The temp warms up very quickly after the door is open. Only complaint I have heard is one guy complained because his feet sweat when working on those floors. One of our CAT shops has this.



My father has a ground source heat pump to heat/ cool his house. The initial install is pretty steap, but you reap the savings for a long time. We had three wells dug in the back yard 150 feet deep, and a trench about 12 feet deep. A closed loop of plastic pipe goes out of the house and down each well back to the top to the next well then after the last well back into the house. There is sand packed around the pipes in the wells and the trench. It is hooked to a pump with a heat exchanger. Has propane furnace back up. Dad and mom live in a 100+ year old farm house. It keeps it cool in the summer, and warm in the winter until it gets down under 10 degrees or so/ or is really windy. The only cost is the power to run the pump and fan otherwise. The first month the A/C cost him about $8 for the entire two story farm house.



Very good setup, its at least 15 years old now, with no problems yet.



Michael

 

[TPCDrafting]

The heat pump system is very efficient. Also cost effective when considering a garage/shop application.

I've been doing some research on waste oil heaters and would like one for my shop if I ever get it built. Not sure if one could be rigged to do in-floor heat, but I can't imagine it being too hard. If you have a source for free waste oil, that might be a route to check into.

As far as a solar application a friend has built a small green house on the south side of his garage (the back side) where he put several 55 gallon drums painted black and filled with water. The room heats up in the day heating the drums. He has a blower fan thermostatically controlled to blow warm air into the garage. It does pretty well, but it's not in-floor heat.

As far as in-floor goes, another tip would be to place rigid foam insulation under the slab to keep the heat in. Possibly add it to the perimiter foundation wall as well. Remember also that in-floor heat is not instant and takes a while to warm up before it is actually heating the space. Not a problem if the heat is left on, but won't be very effective if you shut it off or way down when not in use and you expect to run out to the shop, turn on the heat and have instant warmth. Good luck it sounds like a great shop!