This fan was relatively easy
"This fan was relatively easy to install since our gas fireplace is a Napoleon. There was already a slot for the tab and a pre-drilled hole for the screw. Plug and play made for an easy install, just not much space under there. It works like the instructions say. It turns on roughly 15 minutes after the fire lights and runs for about 30 minutes after the fire goes out. My only problem with it is the screen that goes over the front of the fireplace blocks or slows down a lot of the warm air produced by the fan. So it seems like not much heat is being blown out from the unit for the amount of noise it makes, or for the investment. If I remove the screen there is a noticeable improvement, but then it is unsightly with all of the plumbing and wiring underneath exposed. Time will tell if I would do it again."