Duct leakage in Florida homes commonly runs between 20 and 30 percent of total system airflow. When the ducts sit in a 130-degree attic, which is where nearly all Florida ductwork lives, that leaked air is conditioned air you paid for, dumped where it does nothing. Worse, the return side pulls the same volume back in from the attic, so the system is drawing hot, humid, dusty air into the house and then trying to condition it.
Sealing without measuring is guesswork. We pressurise the duct system with a calibrated fan to quantify leakage before and after, and we take static pressure readings at the air handler to find restrictions. Only then does the actual work start.
A new high-efficiency system connected to a leaking, unbalanced duct system will not deliver its rated performance, and the manufacturer warranty assumes airflow within specification. Sealing and balancing first frequently reduces the size of the equipment you need, which is a rare case of the cheaper fix also being the better one.
Most customers combine two or more of these in a single project.
Short answer: Leaky, poorly designed ductwork wastes conditioned air before it reaches your rooms, forcing your HVAC system to work harder. We seal and balance duct systems to recover that lost efficiency.