i would like to see it work. to be most efficient there should be some sort of baffle welded on the interior of the door directing the air down onto the coal bed, and also up towrads the top of the firebox (to achieve a good secondary burn). I have a unit that is identical to the ridgewood. It is natural draft as well. the door is identical to that of a ridgewood. I ordered and hooked up a fan this fall and it did work great. the only issue i had was small pieces of ash and coals spitting out the top of the stack. I worked with it for a few days and came to the conclusion that the air path to directly on the fire. i believe is the air path was diverted a bit it would work great. I took the fan off and I am now back to running it as normal. I am going to fabricate a baffle for the inside of the door where the air comes in this spring and try it again.
Also, hopefully the fan deisgn that they offer comes with a damper and solenoid kit. These are very critical from my experience. otherwise to much air still leaks in even when the fan is off.
If anyone gets the blower upgrade i sure would love to see some pics!!!