Final Report: Cooling Seasonal Energy And Peak Demand Impacts Of Improved Duct Insulation On Fixed-Capacity (SEER 13) And Variable-Capacity (SEER 22) Heat Pumps

Previous phase 1, 2, and 3 research identified that duct conductive losses to an attic environment imposed greater relative energy losses for the variable-capacity systems compared to the fixed-capacity systems (Cummings and Withers 2011) because of the longer dwell time of conditioned air in the ducts. The purpose of the Phase 4 experiments reported here was to see if duct R-value enhancement would benefit the overall operating efficiency of the variable-capacity system relatively more than the fixed-capacity system. The current Phase 4 experiments (the primary focus of this report) found that this was a secondary effect