I am thinking about putting a wood insert in my existing fireplace, we like to have fires but I want to be able to heat the house as well. The existing fireplace is pretty large 27x44 opening, has a large brick chamber above the damper, then necks down to a 15" square flue. I would like a large insert that will hold bigger splits and have long burn times, as well as be able to heat 2000+ square feet. I would also like to have an insert that is set up for outside combustion air, our house is prettty tight, and burning without a vent tends to dry out the house and aggrivate my allergies. The current fireplace has an ash door that opens into a deep dead space blocked in between the basement and crawlspace. There is a small access to get to it through the crawlspace, was thinking that would be a good route to get outside air to the fireplace since it does not have an outside wall. So far I have found the PE Summit, which looks about the best fit as of now, the Avalon Olympic, and the Lennox Canyon. The Olympic and Canyon I do not believe have an outside air provision. Are there any other good models or brands to take a look at? Also, what size and how far of a run can you put on the outside air intake? If I do it through the ash pit I would have multiple bends and at least 15' of run to get outside. Thanks in advance for any input you can provide.