Blower Motor Assembly: how the HVAC blower motor works in Atlanta homes

Blower Motor Assembly of a residential HVAC system

The blower motor assembly is the squirrel-cage fan and motor inside the air handler that moves air through the whole house. It pulls air through the return and filter, across the coil and out the supply vents.

How it works

A blower wheel with dozens of curved blades spins inside a metal housing. Air enters through the wheel's open sides and is pushed out through the housing outlet into the coil and supply plenum.

Older systems use PSC motors with a capacitor and fixed speeds. Newer systems use ECM (variable-speed) motors that adjust speed to hold airflow steady, which saves energy and improves humidity control.

A dirty blower wheel can lose a large part of its airflow. Dust packs into the blades and the wheel simply can't move as much air even though it spins at the same speed.

Signs of a problem

Weak airflow at every vent
Squealing, rattling or thumping when the fan starts
Motor hums but wheel doesn't turn
Burning smell from the air handler
Air handler runs but you can't feel air

Simple upkeep

Change filters on schedule — it keeps the wheel clean
Listen for new noises at startup
Have the wheel inspected during annual maintenance
Keep the cabinet door sealed

The blower motor assembly in Atlanta homes

Long, humid summers with dew points in the 70s keep the system dehumidifying from May through September. In Atlanta's mix of 1920s bungalows in Virginia-Highland and Inman Park, newer townhomes in West Midtown and brick ranches in Southwest Atlanta, we see blower motor assembly issues most often in homes around Buckhead, Virginia-Highland, Inman Park.

What our technicians check: We pull and clean blower wheels, test the motor capacitor or ECM module and measure total static pressure to confirm the blower is moving the airflow the equipment needs.