I have a 20x22x8 building with 2x4 stud walls 24" OC. It has 2x4 trusses spaced at 24". The building is covered with metal with double bubble sandwiched between the roof panels and trusses. There is no insulation on the walls and the ceiling is open. It has a 9x7 insulated garage door and an insulated 36" walk thru door. I am looking at double bubble for the walls and covering them with cabin grade T&G. I am thinking of adding a single zone mini split later. What would you recommend for the Central Arkansas climate.

