Montana Shop Hydronic Heating
Thanks for taking the time to read this. I’m currently in the process of building a 42 x 80 x 18 shop with SIPs. I used LoopCAD to design 5 ~450′ loops of 3/4″ pex for hydronic heating in a 6″ thickened edge monolithic slab with monoslab ez form arctic forms and 2″ XPS under the entire floor. LoopCAD calculated my Manual J8 heating load at 56,500 Btu/hr for 60F design temp. Electricity is $0.05 kWh after a base customer fee through my electric co-op, Propane has averaged around $1.30 gal over the last couple years. So it seems based on the calculations from those numbers, I should probably install an electric boiler, like the ones from Electro Industries. As I understand it, my peak heating need would be 56,500 to maintain 60F, so I should size my electric boiler around 55-60kBtu. Using a base temp of 50F, I estimate that it should cost around $1300/yr to heat. Does this all sound probable with an electric boiler being the best solution? I may install a couple of heat pump mini-splits in the future that would obviously have better efficiency to supplement a warm floor, but I really wanted the comfort of a warm floor for working on. The slab is finished, and the building is just starting to go up. I appreciate any suggestions and am happy to provide any details that I should have added.
GBA Detail Library
A collection of one thousand construction details organized by climate and house part