Ductwork sealing and insulation

Today was "review the ductwork" day and I'm happy to say that for the most part it was still in good shape.  When the system was installed, all of the joints were sealed with duct mastic and then insulated.

The only issues I found were where the ductwork joined the heatpump itself.   Tape is an evil thing when exposed to attic temperatures for many years as it starts to gets brittle and either loses it's grip or tears easily.  The only option is to take out what's bad and replace it.

Since my ductwork was already sealed and insulated I'm not going to get a huge savings from the work I did today.  On the other hand, it only took about an hour to check it all out and I used maybe $0.50 worth of aluminum duct tape that was left over from a roll used on the solar air heater.

There are several sources (here and here) that suggest that 10% - 30% of the conditioned air in a typical home is lost via leaks in ductwork.  It's an easy and cheap thing to fix...