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Combined efficiency of 2 single zones at minimum modulation? A cop of 10.84?

bfw577 | Posted in General Questions on

I’m using 2 12k Gree Sapphire single zone high efficiency mini splits as my main source of heating/cooling. I have an Emporia Vue connected and have been logging the electricity consumption for over a year. Using the Emporia I verified all the electricity consumption in the NEEP listing for my unit and it lines up pretty much exact with the listed ratings.

On days in the mid 40’s both my units are almost always running at their minimum modulation at exactly 200 watts each. This lines up exactly with the NEEP 200 watt ratings at min at 47 degrees. At min speed my units lists a cop of 5.42.  I also am monitoring the return and supply temps so did a rough COP calculation using the cfm and it matched up. 

Since I am using 2 units do I just combine both cop’s to get my overall cop? So am I getting an effective overall COP of 10.84?

Here is the unit on NEEP. As a note the 5 degree data is wrong and has errors.

12k Gree Sapphire 30 SEER 14 HSPF.!/product/25406/7/25000///0

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  1. aunsafe2015 | | #1

    Unless I missing something, it seems to me that two units each running at a COP of 5.42 would be a combined COP of 5.42?

    1. Trevor_Lambert | | #2

      That's correct. Assuming they are both contributing the same amount of heat, you just average the numbers. Otherwise you have to weight the relative contribution. In no scenario can the overall COP be higher than the highest single COP.

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