We have 2 zone HVAC from Goodman. One unit is in the Attic, it's capacity is 39,000BTU (contractor mentioned). Builder said that this is enough when we finish attic room which is approx. 400 sq.ft. We hired local contractor and finished the attic but it is not conditioning the attic well. We do not see enough air coming out. Can you please tell me what might be the reason? Is the capacity not enough?