Been working on the a/c ducting today. We've had several experts tell us our a/c unit needs replacement. However, yesterday, two more experts disagreed. They did say that we have some problems that could be fixed, but that our unit is still working fine.
So, I spent the morning in the attic with my son spreading some mastic around the junctions of the room ducts and the main trunk running the length of the house. The estimate is that we were losing at least 200 cubic feet per minute of airflow around these joints. So, $11 of mastic and about 45 mins of work later, we'll see.
Also, no one had ever told us that our return to our air handler was too small. We have a 5 ton unit, which most resources say needs about 1000 square inches of return. We only had 640. We now have exactly 1000 due to the two new 25" x 20" returns Chris and I installed. While we were doing that we took the time to seal up the return box (under the air handler) that was obviously pulling air in from inside the walls and probably straight from the attic. No wonder we were running hugely high summer cooling bills.
Time to reward our good work with some lunch and a trip the movies. I think Prometheus is on tap.