I own a condo in a converted 3 family home; it's the 3rd and 4th level. The 4th level is a converted attic to studio. The house has a steep pitch roof, so there's no regular windows in the 4th floor, just skylights.
Have a friend, who works for a commercial HVAC company, come look and told me the best solution was to install the split ductless indoor unit(Sanyo CL 1872, 1.5 ton), inside a crawl space that's up against the ceiling of the 4th floor. The crawl space area is somewhere around 9x9 feet, with the ceiling just about 5 feet high in the middle...not a lot of space, not any ventilation beyond the ridge vents. His solution was for me to have someone come in after the install and put an exhaust fan cut into the roof to suck out the hot air. It sounded reasonable at the time and they did the install(sans exhaust fan).
Made a call to someone to come do the exhaust fan...he wanted to check with another HVAC person before doing that, didn't think it sounded "right"...long story short, have talked to 3 other HVAC people who all told me that application wasn't correct, and I ran the risk of it not working efficiently, and the fan could burn out quickly, ect.
Now my last issue/question: if I put the condenser off the ground outside(NOT DYI, I'm having someone come actually tomorrow to start the work), I believe the line set will go beyond the max 35ft the unit is designed for....so what happens if the line set is 40, 45, or 50 feet? The 4th floor is probably 35 feet in itself, then running the line inside to the control unit will go beyond that.
I'm at my wit's end with this, and seems like even with different HVAC people I've spoken with, I'm getting different opinions. Thanks!