Heating a shop help please

I have a 40 x 60 pole barn with 12 foot ceilings that I plan to insulate and add a concrete floor.  I just want some basic heat up to 50 degrees or so in the winter.  Any advice as to the most cost effective heat to install but yet keep my monthly heating bills reasonable as well????

I use an oversized forced air heater, because I can turn it up and heat the air in 30 min. Sometimes I only get a couple of hours every other day to work. In between I leave the heat low or off.

I built a shop 40 by 40 with a 16 foot ceiling 1997 and wish I would of put in floor heat. I built a furnace out of a 3 foot propane tank. Walls are 6 inch insulated and 8 inch insulation in ceiling. It doesn't take much wood to heat it. We have furnace on and if we don't fire it up for 2 days it still is above freezing. Fire it up and half hour or so and it is over 60 degrees.

Working on a warm floor sure beats working on a cold one.

I would bet with good insulation, in floor tubing and the geothermal system, you could keep the whole building at 45 degrees without using any other heat source. After the initial input costs, all it would cost to keep it 45 would be the electricity to pump you coolant down in the ground and back through the lines.
 My brother built a new house a couple years ago and put pex tubing in the basement floor. He said if he could do it over, he would add about 8 inches of sand on top of the insulation before pouring the slab, just to add more heat sink to the whole thing. It would take a lot longer to notice a change in temperature if he lost power.


Edited by CTuckerNWIL - 23 May 2011 at 12:16am

I put a radiant heater, a tube heater in last winter, it heats the equipment and keeps the floor warm, but if i was pouring a floor flor heat would be hard to beat.

I have a solar heater for my shop. Works great in the summer.  The winter time, not so much.

In floor heat is great if someone is going to be out there every day but if the day comes where your only to be out there once in a while, or gone for the winter, it will need to have antifreeze in it or be drained.

In floor heat plus use spray  foam 3 inches in the walls and 2 inches of foam below the cement pad. At least R40 in the  ceiling.

Vapor barrier, 2" EPS foam, concrete with PEX tubing... and add any heat source you want... electric or gas water heater... a wood-stove with liquid heat exchanger... solar panels... whatever you want, whenever you can.

The other big advantage of heated floor... you can set the interior temp however you want... the floor will be warm... open the overhead doors and let a blast of cold air fill the building.  Close the doors, go back to work, and you won't feel a bit cold.

Finally... condensation.  Warm floor eliminates it.

My 'old' workshop has a concrete slab, and I can set that overhead furnace to 75F, let it cook for a day, come in there, and that slab will still be cold enough so that carpet simply won't fix it.  I was introduced to tubing-in-floor 10 years ago, and I've never poured a concrete floor since... without tubing.    My south porch (where I"m sitting right now) is a semi-passive solar collector during the winter... dyed dark black, and only gets direct sunlight between autumnal and vernal equinox... I run water through the floor, and direct it to the basement to move solar heat to the north side of the house... but during summer, I trickle cold well water through it to cool the house.  Man, it works.  I even put down an insulated barrier floor using lime and a plate compactor, embedded 1/2" pex in there, and put PAVER BRICK atop it in my wife's garden-shed / hen-house... and I heat that floor with an ordinary 1500w ENGINE HEATER and a surplus 1gpm electric pump, both controlled by a cheap thermostat and a relay.  Set to 50F, it never freezes, and the hens don't need as much food.

Oh, and no worries about anything freezing... I use propylene glycol.  100' of 1/2" pex is about a gallon (it's 0.0092gal/foot)... and propylene glycol is about $2.50/gallon.  Propylene is the pink stuff (RV anti-freeze)... non-toxic, and good to temps well below what you'd ever find in an insulated workshop.