Short cycling a myth with minisplits?
bfw577
| Posted in General Questions on
It appears that Midea mini splits dont really short cycle. I have been monitoring the electric consumption which gives me a clear picture of the compressor modulation. I have yet to see any short cycling of the compressor in a few months of data monitoring. Not sure if all units have the same algorithms but Midea definitely seems to just throttle the compressor output and briefly surges it.
I know short cycling of mini splits is talked about alot and thought I would share my findings.
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Replies
The graph posted looks like short cycling to me.
If the 250 watts base line is the indoor blower fan and the 550 watts spikes are the compressor running for 3 minutes and off for the next 33 minutes.
Walta
The compressor is still running and can modulate lower than 250 watts. The fan is rated at 20 watts full output.
According to the Northeast Energy Efficiency Partnerships database it is running at a cop close to 6+ at that level of modulation.
Another myth is that it matters if inverter based heat pumps do or don't cycle (or even short cycle). The manufacturer knows the most about which is better when. Let them decide and pay attention only to sensible and latent performance at your load points.
Mini splits will short cycle once the load gets low enough. The key is for this not to happen under typical conditions.
In case of your unit, it is running on the low end of the output (good for efficiency for most but not all units) but above the low limit.
The power spikes are typical to get the oil back to the compressor.