kduboh,
The grates do work, but the fan can get pretty noisy. They do kick out the heat though, much better than it going up the chiminey! Draws in cold air, and will blast out the hot air. I used one for many years, a Heat-N-Glo, paid $288 for it back in 1990. I put in a gas unit last year(remote control and all), the old Heat-N-Glo is still in my garage, still works great, just could not throw it away! If you ever get up this way (chilly Madison WI) let me know, I'm looking to give it away to someone that could use it.