3 ms·

I am not sure that it is true that split system ACs are substantially less efficient than central. And depending on the size of your unit and how much space you

I am not sure that it is true that split system ACs are substantially less efficient than central. And depending on the size of your unit and how much space you can leave unconditioned, it can save substantial energy to use a split solution. For example, we used space heaters during the winter in cali to save substantially on energy. This is because even with much less efficient electric heating, heating just two bedrooms at night is more efficient than heating the entire house. (We saved hundreds of dollars each winter despite that a btu from an electric heater costs two or three times as much as a btu of gas.)

EricE 6y ago
Exactly - obviously the larger the home and more uneven the occupancy, the more the individual units make more sense. And you don’t have to have one indoor unit per outside unit. Systems that can have one outdoor unit with up to four inside units are readily available. What’s really wild is Mitsubishi’s City system - designed for commercial spaces (or really large homes) you can have dozens of internal units. And more impressively, it can move heat around inside the building. If you were having a party in the middle of winter and all the body heat was heating up the room where everyone was you could “AC” that room and then dump the heat elsewhere in the building. The key is the per-room zoning. Minisplits are by far the easiest and most efficient way to micro-zone. Also the elimination of loss from ductwork should not be discounted either; it’s often very significant. Especially if you can eliminate ductwork from unconditioned space!