Whats the most important factor in purchasing a heater or air conditioner?
There can be no question about it. The contractor is far and away the most important consideration. The brand you choose, the SEER rating, the type or features of equipment are all second to getting a good contractor. He is the final builder of your product and determines how well your system will work. Remember that you are not buying a stand alone appliance, you’re buying a system. The manufacturer only provides the pieces. The contractor determines how they work. See this essay on what that means. I say basically the same thing here and here.
