website to find COP on heat-pump boilers? (air-to-water heat pump/hydronic)

weil_fail

hey,

in the US, there is an AHRI website to see the efficiencies of lots of different kinds of heat pumps and they have data at different temps. they don't really have any info on heat-pump boilers, though. I guess because they're not popular enough in the US. I know they're popular in the UK and parts of Europe, so does anyone know of a good website where I might find COP data at different ambient temps?

side question: do any heat-pump boiler manufacturers make an all-in-one unit that does high temp? I can find units that don't have refrigerant lines, that just have return and supply water go outside to meet the outdoor unit, but they are all low-temp radiant. I can also find higher temp units (60c-80c), but they all seem to run refrigerant lines inside to some unit that does the boiling. I cannot find any that are all-in-one AND are high temp. maybe nobody makes that, but I figured I'd ask.

edit: by "boiler" I just mean a hot water heating system, not necessarily that the water reaches boiling.

Hot_water_fan

There's a British heat geek Facebook group with a lot of self-reported COPs, but no official website I'm aware of.

side question: do any heat-pump boiler manufacturers make an all-in-one unit that does high temp? I can find units that don't have refrigerant lines, that just have return and supply water go outside to meet the outdoor unit, but they are all low-temp radiant. I can also find higher temp units (60c-80c), but they all seem to run refrigerant lines inside to some unit that does the boiling. I cannot find any that are all-in-one AND are high temp. maybe nobody makes that, but I figured I'd ask.

Not that I've seen in the US, yet. You can get there with an R-134A W2W heat pump added onto the outdoor one but at that point resistance or fossil backup starts to look mighty appealing.

jumper

COP is very different @ 50° than @ 20°. It is especially high in summer for heating swimming pool. Even higher when I combine A/C with pool heater. Then the pool becomes a giant hot tub.

weil_fail

Hot_water_fan, thanks for the tip. I might check out the facebook page. though I would still be interested in some standardized test rather than seeing the as-built system that adds a lot of factors.

jumper, indeed. some website will list COP at different temps, which is what I'm hoping to find. AHRI.neep.org has COP at -13, 5F, 17F, 47F. it would be awesome to find that for some heat-pump boilers

Jamie Hall

I presume you are using the term "boiler" here to refer to high temperature hot water heat? So far as I know there are no heat pump units which actually boil water for steam.

hot_rod

I think all the cold climate air to water heat pumps ccA2WHP, are going to be very similar. They use all the same components, just different enclosures.

This journal is a generic look at how they work, their limitations, etc.

https://www.caleffi.com/sites/default/files/file/idronics_27_na.pdf

I think Canada has a list of various manufacturers specs, maybe at NRCan website.

weil_fail

Jamie Hall, yes I mean an air-to-water heat pump. boiler is just a generic term that I've come to know them as in my area, even if the temp never gets close to boiling. sorry for the confusion.