What heat source is optimum for you isn't going to work for someone else. Weigh everything against a block of salt and then make an informed decision. Without a doubt, the catalytic heaters use a fraction of the fuel that a furnace will use. (3 gals/wk vs 3 gals/day) The down side is they create condensation and suck the oxygen out of the surrounding air. The only byproduct of a cat heater is water that is made through the chemical reaction taking place on the catalytic filament between propane and air. Upside, quiet-holy peace and quiet! Also very even heat in that there are no drafts or blowing air to chill you. We've had both and will never go back to a furnace. I had to replace blower motors on furnaces-catalytics don't even need wiring. We keep a vent cracked in our bedroom and kitchen and we have 2 carbon monoxide sensors (1 in BR and 1 in lounge) that we keep current. (they have a shelflife even if they're not used) We found that if we have a condensation problem it's because we don't have the vents opened enough. We cook and shower daily and live in temps that drop down below zero on occasion. We have 3- 6000 BTU (BR-Kit-Lounge) and a smaller one in the Bath. We also have a baseboard in the bed, hall, and lounge if 50A is available. But the cats are used first. We had Plat Cats originally, but the guy never had time to rebuild them so we replaced them with the Olympic Waves which fit in the same holes.