An AC or heat pump compressor is the part of an outdoor air conditioner or heat pump that compresses and pumps refrigerant to meet household cooling requirements.

How it works

The compressor in the air conditioner or heat pump circulates refrigerant. Refrigerant absorbs and releases heat as it travels between the indoor and outdoor units, helping to maintain a cool and comfortable indoor temperature.

Single-stage and two-stage cooling

Compressors can work at either a single level of operation or two stages. Lennox has the most efficient two-stage air conditioners and heat pumps you can buy.*

Single-stage cooling

Single-stage HVAC systems are the most commonly used systems.

A single-stage cooling system means your air conditioner or heat pump has only one level of cold output.

Two-stage cooling

Two-stage cooling means the air conditioner or heat pump has a compressor with two levels of operation: high for hot summer days and low for milder days. Since the low setting is adequate to meet household cooling demands 80% of the time, a two-stage unit runs for longer periods and produces more even temperatures.

Longer cooling cycles also translate to quieter, more efficient operation and enhanced humidity control. Compared to a single-stage unit, a two-stage air conditioner or heat pump can remove twice as much moisture from the air. This is important because when moisture levels are high, there's a higher potential for mold and other pollutant problems.

See the full range of Lennox® Air Conditioner compressors

See the full range of Lennox® Heat Pump compressors

*Efficiency ratings established per AHRI’s test standard: ANSI/AHRI 210/240-2017 of two-stage central AC/HP equipment.