I'm finishing a space of ~300 sqft in the attic of my 1901 house with a 12/12 pitch slate roof in NE Kansas (Lawrence). I'll have expanding open cell foam blown in to insulate the entire roof, but with ~4 foot knee walls the finished space will be ~300 sqft including a 1/2 bath, 11 x 16 room and tower space.
I've asked for 2 bids and both are saying 1/5 to 2 ton system required. I think I'll use a Mitsubishi mini split. This seems like a big load calculation.
I know there is no substitute for a complete calculation, but I can tell that the people on this site have a lot of experience and I'd like to know if this sounds reasonable. Thanks for your help. The rest of the whole house is ~2300 sqft and 4 tons.
P.S. One more question: Should I insulate the knee walls? Space "behind" the knee walls and 3 gable ends will be unconditioned storage space.