Heat pump wall units
FishHeading
| Posted in General Questions on
With a mini-split heat pump system with one heat pump outside and then several wall-mounted indoor units, most of the electricity use is the main pump outside correct? If people inside the house run one wall unit or three that shouldn’t make a great different in electrical consumption?
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Replies
The indoor fans are very small loads. My guess is less than 100 watts.
Note oversized multi headed mini splits systems are a recipe for unhappiness.
Walta
The outdoor units typically don't ramp down very well so while in theory they should be able to modulate to match the interior loads, when the loads are relatively small--i.e., only one head calling for heating or cooling--you'll be paying as much as twice what you should be for the energy.
"If people inside the house run one wall unit or three that shouldn’t make a great different in electrical consumption?"
Wouldn't this be (somewhat) akin to saying most of the electrical consumption of a well water system is the pump, therefore it doesn't matter if you have one faucet open or ten?
Somewhat bad analogy since faucets use zero electricity, but hopefully you get the point. If what you say were true, it sounds like free energy.
But what Walta and Michael are saying complicates it a bit because you may in fact be paying more to run one unit than you should (compared to a 1:1), thus running the second unit may be more of an incremental usage in this way, when loads are below minimum modulation.
Running 3 units will use a lot more electricity than running 1 - the outdoor units energy goes to supplying the indoor units.
Running 1 outdoor unit connected to 3 indoor units usually uses more electricity than running 3 outdoor units connected to 1 indoor unit each.