Clean/new wicks are a must. You may be able to burn it dry and recondition the wick you have now (gets rid of the carbon buildup on the wick and makes it burn cleaner). With the 23k BTU one like listed in cglascow's post, I light it inside, but check the flame for the first 10 minutes and then in about 20 minutes to make sure it's burning clean or it will smell. And ALWAYS carry it outside to shut it off or the smell will be terrible. I do get a noticeable odor, but it's not offensive at all. I don't do much work laying on the floor, so Carbon Monoxide isn't much of a problem using it. I've burned it for 6-8 hours in a closed up 3-car garage attached to my house with no issues - other than a 70 degree garage and 20 degrees outside makes for lots of condensation on stuff in the garage. I usually keep it 50-55 in there and then shut it off.