Rheem releases cold climate heat pump!

[EatenByLimestone]

-30C!

US manufacturer releases cold climate heat pump

Rheem has unveiled an air-source heat pump that provides uninterrupted heating under -30.5 C ambient conditions. It has successfully passed the US Department of Energy's Cold Climate Heat Pump Challenge.

www.pv-magazine.com

 

[peakbagger]

I saw that but until I see details on the actual COP at lower temps I am unsure if it still is a good primary heating source for cold climates. If the COP goes down to 1 at low temps it still puts lots of load on the grid during a period when power capacity is an issue in many areas.

 

[SpaceBus]

The efficiency is very impressive.

 

[stoveliker]

Cop between 1.5 and 2 at 17 F.
77 pct of nominal heating capacity at -15 F, but no data on what electric power it needs then. (I.e. whether it is merely an expensive cop=1 heater then...)

But they beat the DOE challenge by 5 pct. Generally these are not easy (though not unachievable).

 

[woodgeek]

Cop between 1.5 and 2 at 17 F.
77 pct of nominal heating capacity at -15 F, but no data on what electric power it needs then. (I.e. whether it is merely an expensive cop=1 heater then...)

But they beat the DOE challenge by 5 pct. Generally these are not easy (though not unachievable).

My 10 year old unit has a COP between 1.5 an 2 at 17 F. LOL. Just really low output.

 

[stoveliker]

My 10 year old unit has a COP between 1.5 an 2 at 17 F. LOL. Just really low output.

So, now I looked up my unit again.
My Mitsu has a 62% of nominal output at 17 F with a COP of 2.67 ... I.e. even better (at 17 F) than this one. (and the COP only down from 3.5 at 47 F)
A 38% cut in BTUs tho.

 

[SpaceBus]

The COP isn't as impressive as the high output at lower temps. If the alternative is resistive electric heat, this is definitely an upgrade

 

[stoveliker]

I agree, it's nice to have 3/4 of the output available (at more than resistive heat COP) at a whopping -15 F.

 

[begreen]

So, now I looked up my unit again.
My Mitsu has a 62% of nominal output at 17 F with a COP of 2.67 ... I.e. even better (at 17 F) than this one. (and the COP only down from 3.5 at 47 F)
A 38% cut in BTUs tho.

Yes, I am waiting to see what Mitsubishi, Daikin, Bosch, etc. bring to the table for their next-gen entries.

 

[stoveliker]

Yes, I am waiting to see what Mitsubishi, Daikin, Bosch, etc. bring to the table for their next-gen entries.

Yes, although the (still 20%) reduced output at very low temps still forces one to buy a larger unit than otherwise needed in cold climates. So they need a good variable compressor speed (like Mitsu, I believe), otherwise the high BTU at low T advantage is offset by other issues.

In the end, I'm of the impression that most of the country does not need this, most of Europe neither. The one I have quite suffices for a large part.

So how useful is the push for even colder climate performance than what we have now? I have my reservations. We're already in a pretty good spot with these machines, even though most people don't see that.