Looking to heat a 2500 sq.ft SIPS house in north Georgia , I found a "Lennox" wood burning fireplace that is supposed to do 2500, does anyone have experience with that model or other manufacturers?

I have installed an RSF, EPA certified fireplace. It is rated for up to 70K BTU/hr. The home will have radiant heat in the basement and 1st floor, with hot water baseboard in the 2nd floor, and it is a full SIP structure. I believe it will be almost enough to heat the entire home on a very cold day. However, when pricing out these units, be aware that the chimney is VERY expensive. Because it is wood burning, and highly efficient, it requires a Class A flue. These run between $180 - 240 per 4 foot section. I have not tested it yet.

Is class "A" flue the triple wall/insulated/vented type? If it's the same pipe as for a "standard" wood stove/fireplace some shopping around should yield a better price. My install in 1988 (yes, some time ago) was $90.00 per section.