I have two flues in my chimney. One goes to my fireplace on the main level, the other one goes to my oil fired furnace and oil DHW in the basement (yes into one flue, that's how the house was built in 1986). I don't want to put the Koker or 140 to that one flue, but I want it near the other furnace. I only have one wall I can come out of there. The basement at that point is a half foundation, and outside that wall is my deck. My town inspector said there is no code stating if I can go out that wall, and it must be installed per the mfg instructions. I can't find info on these two units about how to install them. I could power vent, but if I could install in near the exterior wall, and if the exhaust vent is low on the unit, would a 2-3 foot vert run, and 2' horiz run outside the wall give me enough draft without a direct/power vent? Seems like a type of install someone has probably tried.