Existing Appliance Performance Air source heat pump – COP at 47F is 3.6, COP at 17F is 2.5 – Assume average of 3.0 – Actually two heat pumps in house, assume both are same (similar performance) Gas furnace is 80% AFUE Use on a seasonal heating basis – 4600 kWh of electricity (15.7 million Btu) – 31.4 MCF (31.4 million Btu) We need 76.2 GJ/heating season in the house
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