From a Duckpond attic to a finished air handler, one day in order

7:40 a.m., the call

Picture a homeowner on NE 7th Street calling the number at the top of this page. Her 1915 bungalow has a 2008 air handler in the attic, the blower has started to squeal, and a faint brown stain is spreading on the hall ceiling below it. We are answering from the Palm Coast headquarters, 79 miles and roughly 115 minutes away, and we tell her that honestly: the truck already scheduled for Alachua County that day can reach her by late morning.

11:15 a.m., the diagnosis

The blower motor bearings are gone and the secondary drain pan has rusted through. The unit is seventeen years old and runs on the older refrigerant. Repairing the motor and pan would buy a year or two; replacing the air handler, and the coil inside it, sets the house up for a new condenser when that fails too. She asks what changed since 2008 that makes this more than a straight swap.

What changed in air handlers

Two things, and they are connected. Efficiency ratings moved to SEER2 in 2023, a test that pushes air against more realistic duct resistance, so the blower’s ability to deliver airflow against real static pressure now shows up in the number on the yellow tag. And the refrigerant changed: new Lennox equipment ships on a low-global-warming-potential refrigerant that is not compatible with coils and metering devices built for the old one. A new condenser practically requires a new indoor coil, and in most cases the sensible move is a new air handler built for it. The days of replacing just the outdoor unit are mostly over.

What we install now

For the historic districts and the 1970s ranches alike, the Lennox air handlers we quote share a few features: variable-speed or multi-speed blowers that dehumidify better in August and run quieter through old duct; factory coils matched to the current refrigerant; electric heat strips sized for the house, since most Gainesville homes outside GRU gas territory heat with the air handler on freeze nights; insulated, sealed cabinets that stay dry in an attic where the dew point reaches 72; and space on the return side for a deep media filter, which is how we fight the late-January oak pollen without starving the blower.

12:30 to 4:00 p.m., the install

The old unit comes down the pull-down ladder in pieces. The platform between the rafters gets a new secondary pan with a float switch, and the primary drain is re-pitched to the exterior with a cleanout and a trap, because Gainesville’s shaded roofs and damp attics grow algae in drain lines. The new handler goes up, the coil is pressure-tested with nitrogen, the line set is evacuated, and the heat strips and thermostat wiring are landed and tested. The old flex duct connections at the plenum get new collars and mastic; we do not re-duct the whole attic without a conversation, but we will not connect new equipment to a leaking plenum either.

4:20 p.m., the check

Static pressure across the new unit, temperature split across the coil, amperage on the blower and strips, and the float switch tested by lifting it. Then a walk-through: where the filter is, how the cleanout works, and what the drain stain means if it ever reappears.

Other places the air handler lives here

Not everyone’s unit is in an attic. Haile Plantation and Westchester homes usually have it in the garage, which makes the swap faster. Many 1970s Northwest Gainesville ranches have a closet unit off the hallway with a filter grille in the ceiling. Student apartments near campus often have a small horizontal handler above the water heater closet. Each is a different afternoon, but the order above holds.