Built house 4.5 years ago. Its a 2000sq ft home with high ceilings. the house faces west and has alot of windows. My home is located just north of Dallas Texas. The problem is my side of the house stays warm in the summer and cold in the winter. Another problem is my house keeps a high humidity level. It will stay around 60% in the summer. My original installer has not done much to help the sitiuation. I even installed a de-humidifier to bring down the humidity. I have hired another installer to help me out. He tells me after doing a manual j test my house only need a 4 ton unit. My homes has a five ton unit. He also tells me that my side of the house does not have the correct duct size of vent size to properly cool it off. He has given me two choices. I can re-duct the house and add the proper vents and returns or I can start over with the correct size unit and ducts. The price of the reduct is $$$$, and the unit would be $$$$$$. That unit is a 4ton 16seer heat pump from carrier. I think its called the infinity series. My current unit is a 5ton 12seer goodman heat pump. There is a 1000 rebate on the new unit and he will give me a cash credit of $$$$$and buy my equipment for a $$$$ dollars. That will bring the price to $$$$$. Forgot to mention that my current unit has a freon leak also. I would also have to pay to fix that if I stay with the current unit. Now the question, which way should i go? I am willing to buy the new unit if it will fix my comfort issues and mabee save me energy money? Any advice?