Traditional ducted, split system heat pumps have constant-speed compressors. Ducted, variable-speed split system heat pumps incorporate variable-speed compressors, variable-speed indoor and outdoor blowers, and linear expansion valves (versus thermostatic, two-position valves) into traditional ducted split systems. The variable-speed features allow the equipment to operate at the actual load and not cycle on/off, resulting in energy savings of 20 to 66 percent for the HVAC system. The variable speed features also substantially extends the equipment life.
This technology is best used in a retrofit situation with existing air ducts in good condition. Incorporation of a variable speed compressor into a ducted system will save significant energy over a constant-speed unit with energy savings as high as 40 percent. Split systems should be designed and controlled to minimize the use of strip heat and make sure the ductwork is well sealed.
Current Stage: Approved for Implementation. See BPA Energy Efficiency Implementation Manual for measure and program details.