In general the AC in our house works reasonably well (though I haven't done performance tests on it yet). It's a single stage 3.5 ton heat pump/AC original to the house, which was built in 2002. Everything is in the basement with the condenser being about 25 ft away outside.
The house is 2 stories sitting on a basement/garage, and the floors are 2 separate zones. The basement is not insulated beyond 1.5 of the cinder block walls being underground.
All of the branch lines that feed the first and second floor are insulated, but the trunk lines that feed those are not. There are two separate trunks, one for each zone. Both trunks are 6-7 ft long.
On humid days (we're in the south, so every day) I notice a lot of condensation on the trunk lines sometimes to the point of seeing small puddles on the basement floor in some spots.
My question: Should these be insulated (yes, probably?) and if so would there be a noticeable efficiency gain to make it worth the effort to wrap them?
I know there are a lot of variables here so I'm just trying to get a basic understanding or rule of thumb.