You Got me thinking... My AC is 18 yrs old. I have a90% propane furnace that is still like new since I burn corn and pellets. But If I was to upgrade my AC to a hi eff. heat pump/AC that would be perfect for the shoulder season and save some on AC during the summer. My brother is a HVAC/ Comm. Refrigeration guy so I can get material at wholesale and no labor. Kind of a no brainer. I need to run it past him. The mini split set up would not be ideal for my houseSome of you have some incredibly cheap electricity. I would be using a modern cold climate heat pump with those prices.
I am using 2 cold climate mini splits to heat my house powered off my net metered solar panels for practically free. My electric bill is just the $9.62 connection charge every month. I have electricity monitors on both my mini splits and electricity usage averages 250-500 kwhs a month in the winter. Thats the total for both units combined. Most of the day when the sun is out my panels are directly powering my mini splits and still sending a ton of excess power back out to the grid.
These units are making incredible advancements in efficiency even in extreme cold. This LG has a COP (coefficient of performance) of 2.88 even at 5 degrees. That's an effective efficiency of 288%!
This is where the future is heading as heat pumps can be powered from renewable energy such as solar, hydro, wind, etc.