I_e heard horror stories, but for the price I figured I_ chance it. It_ awesome! I have only played with it so far as I haven_ had to really use it to really heat anything. But I look forward to next winter when I can really put it through it_ paces. I have mine set up next to a window in the garage, with a piece of hardy-board cut to fit snugly into the window when open only about 1/3. The air intake and exhaust pipes/hoses both go out two holes in the hardy-board. When running I can_ smell any fumes inside the garage at all. I_e been messing around with it and have got it to run on up to about 2/3 used motor oil and diesel mix. It won_ really start very well, however, on anything more than about 50/50 used motor oil and diesel. Be advised, this is not what the manufacturer intends. But I own it, so I do what I want. Burning 50/50 I heated an insulated 3 car garage from 45 F to 70 F in about two hours, and it was about 30F outside at the time. And the tank (maybe 1 gallon or so) will last for about 8-9 hours on the highest setting. It_ pretty amazing