It’s all in the duct work is what I preach! I get on my soap box about the fact that no matter what the efficiency of the equipment may claim to be, it is only as good as the duct system attached to it.

The majority of duct systems today consist of long (Flex) runs. This insulated vinyl corrugated duct design to accommodate air flow is actually a high resistance to air flow. Multiple flex runs of long length in any duct system is like chocking your HVAC system of air. The end result is the air handler is working longer and harder to achieve comfort. There is the other issue of having any galvanized metal duct insulated on the inside. Why take chances!

The alternative to the above is to have a properly design duct system that will provide three things.