Looking for a way to heat my garage. I've tried propane heaters, but the fumes really sting my eyes after a while so that's not a good option. Tried an electric water heater and a circulator pump feeding a Modine-style heater hanging from the ceiling, but the electric heater can't recover fast enough. So I had a new idea... I've got a couple V-8s kicking around. The temp gauge in my car always reads 190 or so, so I figure the engine is sort of a big water heater. I've run engines on stands before so I could check for issues before installing them, and thought, what if I put an engine outside the garage on a stand, and ran the radiator lines through the wall to the radiator on the inside of the garage? Put an electric fan on backwards to blow air across the radiator and into the garage. Let the engine idle outside, continuously delivering hot water to the inside. No more propane fumes - just clean hot air. Anyone tried that before?
I would bet that you would be the first. I actually applaud you for being imaginative and thinking "outside the box".
I've run engines in the garage before using a flex pipe from the exhaust to the outside, but seems like the unloaded idling motor doesn't put out that much heat when it's really cold out.
I like the idea and it would be easy enough to try. And take it a bit farther and hook an alternator to it as if you would not have one anyway. Use that alternator to charge a couple batteries and run an inverter off of it. I have a small 2000 watt continuous inverter that will run my Mig welder with gas hooked up. And it will run a 5000 BTU ac unit.. I wonder if it would run a Heat unit also. One of the the Moore Oklahoma tornados took out the electric in my sons neighborhood for 3 weeks. He told me he was most worried about his fish dying in the fish tank. He had a Ford 4 cylinder car Festiva that got 38 MPG. I took a battery and my Inverter to his house and some jumper cables. Ran the cables under the garage door to the extra battery and hooked up the inverter. It ran his central Heat system (Natural gas) his refrigerator the kitchen lights and his TV and video games and the fish tank. He ran it for 2 weeks until they got the power back on. The inverter would shut off if battery voltage got too low and he would go start the car and let it run for some time and charge it all back up. 3/4 of a tank of fuel and tank is 12 gallons. Like stated above the exhaust gets hot and could be another source of heat. Run it through a homemade muffler. say 55 or 30 gallon barrel in the shop with a fan behind it.. run the box fan off the inverter. Make a hot plate area on it and cook some beans and if you are crafty you could make a sealed box oven in the barrel and make cornbread. You are welcome.
better yet, get a semi-trailer unit off of wrecked unit, set unit outside off shop wall. they heat and cool. Also run for ever on diesel fuel.
Back when I used to snowmobile, I had this tray that strapped onto the big exhaust muffler called the "Hot dogger". It was so you can warm your lunch up while you ride, then pull over and have a hot lunch. A quick no BS story...I heated up my father's paratineal dialasis bag off of it and he did it right in the woods in Vermont. (crazy thinking about that now).