Compare HVAC quotes for a house that cools eight months a year

Most slab houses in the eastern suburbs were built with the system oversized, and a quote that matches the old tonnage carries the oversize forward. In this humidity an oversized unit cools the air quickly and shuts off before it has dried it, which is why so many houses here feel clammy at seventy-two degrees. A room-by-room calculation is the line that fixes that, and the one most often missing.

The model numbers say what the efficiency is, whether the compressor stages or runs at one speed, and how the unit handles a long humid shoulder season. A phrase like high-efficiency system says none of it. Ask for the numbers and look them up.

On a slab house the ducts live in the attic, where the air around them is well over a hundred degrees for months. A duct that leaks there pulls attic air into the house, and a duct with thin insulation warms the cooled air before it reaches the room. Testing, sealing and re-insulating them is real work and a separate line.

Reusing the old copper is quicker on the day, and it is the usual reason a new system loses its charge by its second summer. Whether the line set is replaced or flushed and pressure-tested, and where it runs, belongs in the number.

A new condenser can need a larger breaker, a new disconnect and a whip, and on the older housing inside the loop sometimes a panel with room for none of it. Whether the electrical work is in the quote or in a surprise afterward is the difference between two quotes that read alike.

An air handler above the ceiling drains all summer, and here summer runs from April to October. A secondary pan, a float switch that shuts the system down before the pan overflows, and a drain line that actually slopes cost little and are easy to leave off. A living room ceiling replaced in August is not.

Winters here are short but not absent, and a heat pump needs something for the handful of nights below freezing. Strip heat, a gas furnace kept as a backup, or a unit that rarely calls for either are three different January bills, and the quote should say which one it is.

A system installed and switched on is not a system installed correctly. Refrigerant charge, airflow across the coil and static pressure through those attic ducts are measured or they are guessed, and in this humidity a guess shows up as a house that never quite dries out. Ask for the start-up sheet.

Memphis, Shelby County and each suburb inspect on their own terms. Included, billed separately, or left to the owner are three different deals, and only one puts a licensed name on the record the next buyer will want.

The old unit and its refrigerant leave the property somehow. Recovered by someone certified, hauled to a yard that takes it, and off the driveway before the installers leave, or left beside the garage until somebody asks. The line should say.

The manufacturer covers the compressor and the parts, usually only if the unit is registered within a window the homeowner never hears about. The contractor covers the labor, which is what fails first, and in a cooling season this long it fails sooner. Who registers the unit and how long the labor is covered belong in writing.

A thermostat that cannot run the system in stages, or that has no idea what to do about humidity, undoes the point of the equipment above it. Whether the quote includes a thermostat matched to the system, and who sets it up, is a small line with a long consequence here.