My shop is 35x70 and about 20-22 ft at the peak of the roof plus a room in the middle of a long side about 10x12. There is some spray on celulose junk that sheds a lot of 1-2 inch lumps. Not very much R value but anything helps. Insulation is about 25 yrs old. Prev owner left a suspended propane fired fan circulated heater, pretty big but I have never fired it up. He also left a home brew waste oil heater the size of a 45 gal drum made from a pressure vessel, pretty stout. He trickled waste oil into it and vented the stack out a window with 4 inch flue pipe. Was said to work well, I haven't used it. I have a propane powered overhead IR unit like you see at outside eating areas with the tank in the base and a big aluminum flying saucer reflector on top. It doesn't heat the building much but will make the area under it anything from just barely warmer to way too hot for human habitation, just adjust the twist knob. It has a safety pilot and piezo electric ignition.
I am thinking of puting it up on a raised pedestal to gain two benefits. 1. won't melt my cap off my head while my feet are freezing due to head being close to heat element and feet 4 times farther away. 2. will heat a much larger area of the floor space.
I expect raising it to greatly reduce the differential in heating over the variance of altitide from my feet to head. I like it a lot because it is virtually instant comfort and I can easily work in the coldest weather (near 0) with out wearing gloves which interfere with my progress. I frequently tip it about 30 degrees to put more heat on one side of the pedestal.
Not arguing against any of the other successful heating strategies but for quick comfort without having to build a fire way in advance and not having to burn enough fuel to actually heat the air and contents of the building radiant is the way to go. I am thinking of building a radiant unit for myself. It is essentially a big burner (like a bunsen burner) with a flue pipe where the hot flue pipe extends for quite a distance to efficiently radiate heat before it is lost up the vent. You run the hot exhaust pipe along the axial focus of a reflector trough that directs the IR downward or down and sideways if you mount it along a wall. Seen these things at a barbeque place in San Antonio with outside picnic tables. Boy howdy did they put out the rays, you betcha. No electricity required, just use a self generating milivolt system with Piezo ignition.
Good luck, report what you do and how it works.
Patrick
