I just bought this two story legal duplex in the Bay Area CA. We do not have freezing weather, but still need heating. The other houses in the area have wall furnaces, so I thought it is a good idea.
There was One floor furnace in the upstairs, due to vandalism(house was bank owned and vacant) parts of the furnace was stolen and to replace probably will not be economical. I was thinking to replace the furnace with a wall furnace. The upstairs apartment will have 3 10x10 bed rooms, one living room, eat in kitchen, one bath and a large dining room/family room in the back. total about 1000 sf.
I was thinking a 35000 btu wall unit in the middle near the old floor furnace. Or should I put two, one in the front room and one in the back dining/family room.
Another reason to close that floor furnace opening is that since each unit has its own entrance, I don't want the upstairs tenant to access down stairs because of the furnace problem.