I also use electric heat
I heat a 900 sq ft woodshop, well insulated on the second floor, a 1200 ft metal shop on a concrete slab, and a 1000 sq ft garage on a slab with electric heat in MICHIGAN....brrrrr. I keep the metal shop about 55 F, the wood shop about the same, and the garage was 48 F last I looked earlier tonight outside temp at 5 F. I am an energy HOG and as hard as I try my electric bill last month was $320.00. I anticipate this month's bill will be over $400.00 because of this bitter cold snap. I can add addition heat with propane space heaters If I was going to work out there on the vehicle OR just turn up the thermostat on the wall furnace.
The heaters in the shop are both HD 240 V 30 amp floor models with thermostats also. Ya want more heat? just turn up the dial, but watch the electric meter take off. :frown2:
I have no rust anywhere, but the walls are insulated and TYVEK wrapped on the exterior and Cedar sided. The slabs are similar to a besement in that they take a long while to change temperature... thermal mass is what is happening. There are SOUTH facing windows which let in some solar heat during the day.
The answer to your question will only be as detailed and specific as the question is detailed and specific. Good questions also include a sketch or a photo that illustrates your issue. (:< D)
Last edited by woodnthings; 12-28-2017 at 10:14 PM.