Garage heat

And just what are you going to use for fuel? Thanks for spending the OP's money. "I'd assume" that if he has an un-insulated garage, he likely doesn't want to chisel up the slab to bury piping. Plus you have to protect a boiler from freezing, which means "running it at all times" in freezing weather. He already mentioned that getting gas to the garage would be expensive...................
read "probably cost to much" and "gas fired" and "might still be plausible using right type heat exchanger..." and your welcome to research wel-mcclain boilers to, thay ant all that expensive less ya heating a high rise apartment building on lake shore drive!! ant spent his money, an pointed out where cost would be over bearing!