|
Greetings: Calculating how much it will cost to heat is not as easy as you think. One item you did not address was how well insulated your space is. Not only the walls and ceiling insulation count, but also the insulation below and around the slab. If you did not insulate the slab, much of your heat may go into the ground. If there is limited insulation in your building any heat that goes into the slab may be quickly lost through the shell. Our 2,100 sq ft house has radiant floor heat which is powered by a 95,000 BTU instant on heater. Our main floor is actually composed of 8 inches of SpanCrete with 1.5 inches of gypcrete on top of the SpanCrete. The tubing is in the GypCrete. Just to get the floor to budge the temperature in the room from say 65 to 67 takes a good 2-3 hrs of constant running. Of course the room then stays warm for many hours. Our house is also superinsulated. The walls are R-40 and the ceilings are R-50. It is also so tight we need a heat recovery unit. With that all said, over half of our heat comes from our wood stove and the passive solar design of our house. Last month was pretty warm for the Rochester, NY area. We used about 85 therms of natural gas which cost us about $70. This therm use includes all domestic hot water use and cooking, laundry, etc. in addition to heating. Oh yes, do not forget windows are a big loss of heat. A typical thermopane window has an R value of around 2-2.5. A low-E window has an R value around 3.5. In summary, I cannot tell you how much it will cost to heat your shop, but if you did not insulate well, most of your money is going into the ground and out through the shell. Let me know if you have questions. Douglas Stockman
Penfield, NY
| 
