Performed semiannual maintenance on two Lennox cooling systems. Inspected all Performance, Mechanical and Safety systems. On the upstairs HVAC system, I found that the unit was flat (empty) on R-410A. I used my electronic leak detector and then soap bubble leak detection solution to pinpoint a large rupture on the indoor coil piping. I also found that the secondary pan for the downstairs HVAC system is extremely rusted out. I recommend replacing the upstairs coil and recharging the system back to factory specifications. I also recommend replacing the emergency drain pan on the downstairs system to ensure in the event of a drainage overflow that no water leaks through the ceiling and causes sheetrock damage to the upstairs area. Did verify that the REME Halo Air Purifiers were on and operating during our visit.