I've talked about ductless heat pumps at some length in other threads and there's little value in covering this same ground yet again. However, it's worth mentioning that the manufacture of my unit (Fujitsu) has replaced this model with one that is twice as energy efficient in cooling mode (21 SEER versus 10.5) and more than 1.5 times more energy efficient in heating mode (a HSPF rating of 11.0 versus 7.2). Moreover, whereas my heat pump pretty much calls it a day when outdoor temperatures fall below -8 to -10C, this one continues to crank out the heat all the way down to -15C (5F). It's just amazing how much the technology has advanced in the space of one year.
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Cheers, Paul