This was inquired before, has anyone experience with it? It is so damned expensive, but has some nice features I am missing on some US designed models. Any thoughts would be appreciated.

Had to browse a bit to refresh my memory. I skimmed a pdf and two things jumped out at me - COP falls to the low 2s as EWT approaches the high temps they crow about. Warranty (in the doc I read) was a very short 12-18 months.

That short warranty is in keeping with a basic concern I have for high temp 410a systems - that the resulting very high refrigerant pressures could be very hard on the system and reduce durability.

I have no first-hand experience with this unit

warranty is now the standard climatemaster 10 year part/5 year labor allowance, at least according to the latest CM brochures. It is equipped with a built in outdoor reset and a separate circuit for the domestic hot water, so for heating it is not needed for all the time to be up to 145, I would suspect only on extremely cold days. 90% of the load may be covered by 125 degree LWT or less. And with a separate circuit for domestic hot water, I guess 135 LWT is the highest we want to have it there. Stiebel-Eltron introduced one in Europe with a max of 70 C (154 F), so the potential appears to be there with R-410a. And yes, they are kind of quite about the COP at that temperature.... My understanding that the high temperatures in part come from plate heat exchangers and insulating the lines inside the unit. I am thinking about putting one in my basement, just to see its performance, before I sell it to a customer.

I agree with your quest for a dedicated potable hot water circuit.

I'm amazed by how small and effective plate exchangers can be relative to other designs - maybe we'll see more of them.

I looked these up as well when inquired about a few years back and agree about prices. It also niggles at the back of my mind that the "high temp" capability went away as EWT from loop field dropped. IOWs for the unit to deliver you also needed extra large loopfield/high EWTs or open loop.
......talk about sticker shock!
j

One would think that the total Heat Extracted would not increase, but decrease, with the decrease in COP, with lower EWTs. Their 145 rated out is at 32 degrees EWT. Yes I was shocked by the sticker, but then the unit comes with dedicated water circuit, outdoor reset built in, all the sensors for the buffer and the hot water tank. So in order to design a system with a year around hot water supply, and this saves you the dedicated extra heatpump, the gap might not be as wide as one thinks.

Why are you interested in THW? Are you contemplating a geo retrofit onto a house with baseboards?

Yes, I have both, cast iron radiators, and cast iron baseboards.I have more applicable projects coming up, but I am reluctant to sell it to a customer without have gathered experience with it myself. In addition, I am running domestic hot water tanks as a zone, giving customers with W-W heatpumps the option of year around hot water. I am intrigued by the separate water circuit for DHW, simply solving all the DHW issues discussed here. May be it simply remembers me of the systems we have designed and built in Germany...