I am in the process of putting in a climate controlled storage facility and was needing some advice on installation of duct as well as the sizing of the a/c unit I will be needing. I will have a total of 4300 sq. ft. of which I will be making climate control. The climate controlled part of the building is approx. 70'x60' with a little extra for a hall way. I have heard that usually you use about a ton per 1200 sq. ft. for this type of application and would appreciate any information that anyone gives!!!!