I purchased this to replace my old propane tank mounted Mr. Heater heater (I know, that sounds funny!) and could not be happier! I did my homework before buying this....and am glad I did. After doing much research and calculating, I found that the estimated cost per hour to run this heater would come to about $.28/hour, while the cost to run my propane heater comes in at about $.80/hour. BIG savings there!As a bonus, this heater came with the optional fan already installed. Awesome!During the installation I did find a flaw in the installation instructions. If you intend to use the fan and wall mount the heater, using the upper horizontal hanging bracket and the lower stand-offs, you will find that the inlet to the fan is mounted flush against the wall--what does this mean? No open air source to allow the fan to move air. (I viewed a youtube where someone else had the same problem with lack of airflow on a wall mounted unit). This is easily remedied by installing 4 - 1/4" spacers behind the horizontal mounting bracket, between the bracket and the wall. This brings the top of the heater unit 1/4" further from the wall, and in turn gives air space between the fan intake and the wall, allowing the fan to do it's job. Interestingly enough, this small adjustment also sets the heater perfectly parallel to the wall and level on the vertical plane.On heating, I am heating a 500 sq ft garage, and find that to reach and maintain a temp of 72 to 73 degrees, I only need to adjust the thermostat to between 2 and 2.5. Set it and forget it, the heater does all of the work.I give this heater 5 STARS and TWO THUMBS UP!