I am considering one zone ductless A/C for a 2nd floor bedroom, for example Sanyo (now Panasonic) KS0971 / C0971, 9000BTU/hr. Would like not to have condenser unit in plain view near a main entryway to our circa 1770 house and would much appreciate professional opinion and caution regarding having the condenser unit installed in our attic.
We are in the Boston, MA area. The attic volume is about 5000 cu. ft. with floor to ridge about 10ft, and two large gable vents with total open area about 18 sq. ft. I would build a rack on which the installer would mount the condenser unit, at the same level as a window in the gable, but about 2 ft. back from the window, allowing space for maintenance / repairs. The window opening is a bit larger than the condenser fan area. I would ask installer to run a short, straight piece of duct (fabric or metal) from the fan outlet side to the window to conduct the hot air right to the outdoors. A small side benefit of this is that the evaporator is only about 8 ft from the condenser.
Many thanks for your advice!