How your home HVAC system works in Atlanta, GA

A central air system moves your home's air in a loop: it pulls warm air in through the return, filters it, cools and dries it at the indoor coil, and sends it back through supply vents. The outdoor unit pumps the heat outside.

Residential HVAC system diagram showing return, supply, thermostat, coils, compressor, fan, filter, control board, blower and drain
Tap any labeled part to read how it works.

What makes Atlanta homes different

Homes across Atlanta (Fulton County, ZIPs 30305, 30306, 30307, 30309, 30318) range from 1920s bungalows in Virginia-Highland and Inman Park, newer townhomes in West Midtown and brick ranches in Southwest Atlanta. Long, humid summers with dew points in the 70s keep the system dehumidifying from May through September. That's why the same parts wear out in a predictable order here: filters and drains first, then capacitors and fans, then coils and compressors.

Neighborhoods we visit often: Buckhead, Virginia-Highland, Inman Park, Kirkwood, West Midtown, Grant Park.

The 12 parts of the system

PartLocationWhat it does
Warm Air Returnair pathThe warm air return is the grille and duct that pulls room air back to the air handler.
Cool Air Supplyair pathThe cool air supply is the plenum, duct branches and adjustable vents that deliver conditioned air to each room.
Wall ThermostatindoorThe wall thermostat is the system's on/off switch and brain.
Evaporator CoilindoorThe evaporator coil is the A-shaped coil above the furnace or air handler where cold refrigerant absorbs heat from your home's air.
Condenser FanoutdoorThe condenser fan sits on top of the outdoor unit and pulls air through the condensing coil, carrying your home's heat away.
CompressoroutdoorThe compressor is the pump in the outdoor unit that moves refrigerant through the whole system.
Condensing CoiloutdoorThe condensing coil wraps around the outdoor unit and releases the heat your system pulled out of the house.
Air Filter AccessindoorThe air filter access is the slot or door where the system's filter sits, usually beside the air handler or behind a return grille.
Control BoardindoorThe control board is the circuit board inside the air handler or furnace that turns thermostat signals into action.
Blower Motor AssemblyindoorThe blower motor assembly is the squirrel-cage fan and motor inside the air handler that moves air through the whole house.
Condensation DrainindoorThe condensation drain is the pan, trap and PVC line that carry water away from the evaporator coil.
Ductworkair pathDuctwork is the network of sheet-metal and insulated flex ducts that carries air between the air handler and every room.

Explore each part

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