Heat pump efficiency
I am designing 2700 sf 2 story house outside Sacramento, zone 3B. BeOpt suggests I will have about a 17,000 Btu heat need. AC is also a big need in summer, and since there is no natural gas, I figured on all electric. Propane appears to be quite a bit more money.
Design low temps appear to be well above 20*; it’s rarely below 29*, and only then for a few hours. Here is the question; my Title 24 consultant stated that heat pumps incur large electrical use when outside temp is cold. I thought newer systems were efficient down below 0*, not that Auburn has seen 0 since the last Ice Age. Are mini-splits different from a ducted heat pump? Should I consider an alternative heat source for cold nights? I will have R21 open cell walls with R4 foam board on walls, R50 non-vented attic in open cell foam, acH50 test specified at 3 or less. PS; my wife does not like air-handler heads, so mini-splits, unless ducted, are out.
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