Efficiency of Air Source Heat Pumps at Cold Temperatures
Anyone know of a good report (based on measured results or research) analyzing the efficiency of air source heat pumps at various low temperatures? Preferably within the last 3 or 4 years.
For example, what is demonstrated actual COP for a few different cold weather air source heat pumps when outdoor air temperature is 32F, and same data for 20F, 10F, 0F, -10F, etc.
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
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Is there anything on this site that I missed that summarizes COP of some of the better cold weather minisplits at various outdoor temperatures?
Here is a page from the 2020 Mitsubishi residential heat pump catalog for some of their "Hyper-Heat" models.
Note the indoor heads are:
"SLZ"=Ceiling Cassette
"SEZ"=Horizontal Ducted Unit
"PEAD"=Commercial Horizontal Ducted Unit
"SVZ" = Multi-Position Air Handler
"MLZ"=Slim Ceiling Cassette
The COP at a specific outdoor temperature and indoor unit varies widely with the size of the outdoor unit. For example, at 47F the "SLZ" ceiling cassette has significantly better COP with the smaller 9,000 & 12,000 BTU outdoor units, but at low temperatures (5F) the "SLZ" has better COP with the 12,000 & 15,000 BTU outdoor units. In most cases it looks like the 12,000 BTU unit has the best COP across different temperatures and types of indoor unit. Not sure why yet.
T, this one is a few years old. They may have updated it but I think they changed their approach in the meantime. But I think it's still a useful document.
Great, thanks!