I`ll weigh in on this a bit, and for the record i`m just north of indy.
My shop is 1920 SqFt with R19 walls under 1/2 plywood and R30 ceiling and I did an air to air heat pump, 14 seer 4 ton
The primary reason is I get (or did at that point More on that in a bit) a break on rates for being...