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mini-split low-temp performance?

is the performance of a mini-split heat pump at low temperatures determined primarily by the outdoor unit? for example, if I install four 9k BTU indoor units with a 36k BTU outdoor unit, will it's heating capacity drop off faster at low temperatures than a 40k BTU outdoor unit with the same indoor units? leaving efficiency out of it, would that larger unit inherently be able to output more heat at some low temperature like 10F/-12C?


  • pecmsg
    pecmsg Member Posts: 4,385
    You have to look at the performance data for each manufacture.
    EBEBRATT-Ed Member Posts: 14,499
    Every Heat Pump looses capacity at lower outdoor temperatures you can't design around it
  • weil_fail
    weil_fail Member Posts: 81
    @EBEBRATT-Ed , sorry if I wasn't clear. I'm not asking if they will lose capacity, of course they will. I'm asking if all things are equal (same manufacturer, same product series, same indoor units, etc.) would a unit that started with a higher capacity continue to have higher capacity throughout the temperature range, when compared to one of lower starting capacity.

    I think I've already answered the question by searching around. most graphs label percentage of rated capacity, which indicates that starting capacity of the outdoor unit seems to matter.