Factors Influencing Space Heat and Heat Pump Efficiency from a Large-Scale Residential Monitoring Study

Since Florida utilities often experience their system peak during the state’s few cold mornings, understanding influences on space heat performance is important to controlling demand. Analysis of heat pump impacts on system load in a large scale monitoring study have shown large levels of strip heat being used during the winter morning peak. The implied coefficient of performance of heat pumps during the system peak hour was only 1.30. Also, analysisof the total seasonal space heat has shown that the impliedHeating Season Performance Factor (HSPF) of heat pump homes is only 4.4 BtuJW rather than the 6-8 BtuJW commonly claimed.Thepaperdescribes reasons forthe lower than anticipated levels ofperformance aswell as other significant influences on space heating demand.