How much more efficient is a new furnace (or, heat pump) over the existing? Is it moreso that there are significant efficiency losses with older HVACs? When reading my question, consider the devil’s advocate here: First, I would argue that new equipment and technology can only be making minute, incremental advances in efficiency. We’ve come a long way, baby, but we’ve got to be way out on the flat part of the curve now. The squeeze in ain’t worth the juice out! Surely, it is asymptotically approaching some value beyond which no HVAC equipment will ever reach. (For one, we all know it is not approaching 100% efficiency!)
Now, at the other end of the scale, consider aging HVAC equipment. A high-efficiency heat pump from the late 1980’s (once everyone was energy conscious) with its tip-top CEER value…will it degrade to some lousy efficiency? If so, where are these losses? Is it a lack of fresh lubrication on the fan motor’s ball bearings? Dust reducing max heat transfer on the surface of the evaporative coil? What?
Or, could it be more that the industry WANTS us to upgrade for their economical benefit vs. significant gains in efficiency?