Why is a variable speed compressor required for many heat pump rebates?

A variable speed compressor is an inverter driven compressor that can adjust its operating speed to match a home’s heat demand. Compared to conventional systems, variable speed systems have higher customer satisfaction rates, increased energy savings and less impact on the electrical grid. For these reasons, a variable speed compressor is required for mini-split, multi-split, and Tier 2 central heat pump rebates.

Variable speed compressors are very common in ductless mini-split systems but are available for mid and high-performance central systems as well. Heat pump installers are advised to speak with their equipment distributors about variable speed product options.

General benefits to a homeowner:

• More consistent indoor temperatures
• Quieter start-up of the outdoor unit
• Quieter operation due to increased time operating at low speeds/airflow
• Lower energy bills and better return on investment

Performance improvements relative to conventional systems:

• Higher efficiency at partial loads and significant seasonal energy savings, beyond what is captured in the HSPF and SEER ratings
• Higher capacity in cold weather and a better match to a home’s heating needs
• Faster defrost cycles
• At partial load operation, lower airflow requirements mitigate issues associated with high static pressure in existing ductwork
• Allows equipment to be sized for heating needs, while maintaining high performance in cooling operation.
• Gradual start-up is easier on equipment
• Gradual start-up is easier on local electrical grids
• Increased performance reduces peak energy demand in the heating season