I have an englander 30 and I was wondering just how much benefit I would get from installing an OAK. It would be simple to try it and see for most but for me I would have to bore a hole through nearly 2 feet of masonry to get it to my stove because it sits back in the fireplace. My chimney is in the center of the house so that hole would have to be bored at a 45 degree angle downward into the crawl space. My stove and apparently a lot of others pull the secondary air and zipper air from inside the house anyway. When I shut the air nearly all the way off after the stove gets up to temperature 90% or so of the air would come from inside the house anyway as the oak only supplies primary air. In doing the math I guess my stove would use about 30 cubic feet of air a minute. 30 X 60 X .018btu X 50 degrees Farenheidt temp rise = 1620 btu's per hour to heat 30 cubic feet of air a minute 50 degrees. Thats about the heat in 3 ounces of hardwood. Also even if the stove was capable of breathing 100 percent outside air the fire would still have to heat the cold air up and in effect would be the same as pulling it from the inside. I'm thinking boring that hole through 2 feet of masonry would not be worth it.