Being in Florida, you should have all your duct work in the attic.
You really should have them inspected. I used to flip houses there. Every one I bought had massive duct leaks on supply and return lines.
Most of my neighbors had the same issue. One of them even had the cap on the end of a 12" supply line completely missing, and it was a 500k dollar
You can buy a flir thermal camera for your cellphone for like 200 bucks. I have tracked down all kinds of leaks and missing insulation with it, as
well aa water leaks, which are a cool temp too.
My last house was a nightmare with ductwork issues.
One big problem with Florida, is the attic temps. Often, they don't use the right products, or don't insulate the ducts, so the duct is heated to 150
degrees and it heats the cool air. Foil tape adhesive fails in the attics and leaks start. The smallest leak in the return line sucks that heat into
the unit and it can't keep up.
They are only meant to change temp like 35-40 degrees, so over 100 degrees on the intake is a big problem.
Around the plenum is another common leak point. You should be able to feel it leak there.
Use foil tape on it then slather on duct mastic to repair, but don't get the lowes crap, go to a ac supplier.
I'd pay to have an inspection of the duct work with a flir, if you are not the diy type, then have them check coil for buildup, keep dust off it and
change filter monthly and check refridg levels.
edit on 4 by Mandroid7 because: Added2