The Buddy Heaters are a nice series of heaters but take my advice and buy the Big Buddy.

The Little Buddy can do 3,800 BTU and is rated for 200 sq. ft.. You cannot use the adapter hose for a 20# bottle with this one because it relies on the propane bottle to act as a part of it's base to stay standing up.

The Portable Buddy does 4,000 on low and 9,000 on high and it too is only rated for 200 sq. ft. also. Both hold just one propane canister. The Portable buddy can make use of the adapter hose to use 20# bottles.

Now the Big Buddy does 4,000 on low, 9,000 on medium and 18,000 on high and holds two propane canisters. This one has a build-in fan that can run for a LONG time on D-cell batteries. It too can use the adapter hose for a big bottle.

If you are like most other guys once you get one of these you will find other handy uses for it and appreciate the extra heat the Big Buddy puts out. I know I sure do. We bring it out to when the kids sled or skate and set it in the back of the SUV aiming out with the hatch open so the kids can warm their faces and hands.

Another one you might want to look at are the radiant heaters that Mr. Heater makes that clamps on the top of a 20# bottle. 15,000 & 25,000 BTU outputs.

But whatever heater you wind up with remember to allow some ventilation to let in fresh air.