Had the guys from Washington Energy Services over today, to see about installing A/C. Showed them the furnace and the technical guy says it can't be done. There isn't enough room to install the coil. They could replace the furnace with one that isn't as tall. For an additional $3k over the already $3k (very rough) cost of the A/C. Ouch. So, they left. I was expecting it to be 2-3, and was willing to go to 4, but not quite to 6. Of course, give me two months and I'll probably be willing to pay 10.