Dear all,

I was at ACEEE2016 in Portland 2 weeks ago, and I saw many presentations about high temperature, CO2 heat pump water heaters for residential applications. They would in fact store more energy in the water by heating it up to 165F. Losses would increase as well, I agree, but it seems like a current trend among manufacturers.

I then tried to search for high-temperature heat pumps, both air-water and water-water, currently available in the market, but I had not much luck. I could only find the carrier GT-PW Water
To Water Geothermal Heat Pump 50YEW (up to 145F), and the climatemaster TRANQUILITY HIGH
TEMPERATURE (THW), that is maybe discontinued as it does not appear on the official webpage. I know that the Daikin Altherma HT (up to 175F) is well known in Europe and Asia, but it is not distributed in the US (as far as I know).

Do you know any other heat pump of any kind, for residential application, able to exceed 140F? It will depend on the heat source temperature, of course, but I would like to start discussin about them in this forum.

thanks,
Maurizio