I have a 125,000 btu Gordon Ray infrared tube. It is 30' long and hangs about a foot below the ceiling. I love the radiant heat, it is so warm and comfy to work under its rays! I have a 500 gallon propane tank to feed it. I pre-buy 1000 gallons per year in mid summer when prices are low. I don't have to take delivery of all 1000 gallons at once, they come out on a regular schedule and keep it full. I usually don't use 1000 gallons, so I get credit for what I don't use. My 50x80 shed is very well insulated, and has no windows, 1 overhead door and one walk in door, so 125k btu is enough, even in -20F temps. It is a very reliable heater, its been here for 25 years with only regular maintenance, except for replacing 1 10' tube about 5 years ago.