It's fun watching you guys argue. To get slightly off the subject but, not too far, my house furnace has a chimney yes, but it's just a flame setting in the basement with no outside air coming in to replenish what it burns except what it pulls in through cracks. And, in the hog barn we have LB White heaters that run on propane they are just a big flame in the room and there is no chimney at all. But, there is fresh air intake in the barn mostly to keep the pigs from dying from there own breathing not from the heater exhaust.
