The practical reality of every home, and the truth behind the challenge of energy efficiency, is that what a manufacture says savings will be, and what happens once something is installed are two different things. Low refrigerant in home air conditioning systems and poor airflow are two big issues in home energy usage.
My house, as many homes do, uses the space between the floor to bring air back to the air handling system. In 1960 it was a nice cheap and effective way to build a HVAC system. With today's concerns about air quality and material out gassing, return air is brought through a duct system.
The contractors arrived today to remove my old air handling units, and install the rest of my geothermal. They ripped out one of the current air handlers.
It did not take long to find the first issue. The supply air duct which comes down to the back of the green air handlers (Silver duct to the left and behind in this picture). has an obstruction in floor joist area.
Looking up into the duct, that has been cut out, you can see another grey/silver duct running across above the vanes coming down. This is hard to see, but essentially the duct blocks 80% or the return air flow.
These are 5 ton air handling units, so the blowers for 40 years have been operating with the added burden of drawing a lot of air through a space the faction of intended design. You cn bitch and scream about the idiots who made the mistake, but this is not a surprising revelation. These units for years have been running with a lot more load to attempt to make up the desired temperature in the zone.
When undertaking these kinds of projects it is super critical to have a contractor with the integrity to point these kinds of problems out. It could have been real easy for them to have masked this issue and I would have been left wondering why I was not getting the right performance from my system.
