ASHP efficiency at low temps
Hello good folks,
I’m finally getting three ductless heat pumps installed in my house to provide heat in the winter. The configuration is 3 indoor single zone Mitsubishi heat pumps, installed 1 to 1 with three outdoor units. They will be used to partially offset the amount of nat gas that my steam heat furnace uses to heat the house. The gas furnace is only 6 years old, and measured 82 AFUE efficiency.
At what low outdoor temperature does an ASHP become inefficient, compared to using my gas steam heat furnace?
I wonder if I can teach the “smart” thermostat for my gas furnace to automatically turn on when the outdoor temperature reaches that magic temperature. Or, alternatively, maybe I could get the ASHPs to somehow shut off when it gets to be just that cold outside.
thanks for your help! Kris
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