hmm as someone about to purchase a heat pump system for heat in a northern climate I am not sure if I should wait...
is this an announcement of a breakthrough or a challenge to find a breakthrough?
is this an announcement of a breakthrough or a challenge to find a breakthrough?
But, if you’re willing to wait or pay extra for the efficiency gains, you might be even better off getting set up with a ground source heat pump now. The install cost is more up front, but because ground temperature is higher than air temperature in winter and lower than air temperature in summer, the differential you need to pump in or out is a lot less, and therefore much more efficient. I don’t think any air to air heat pump in the next 20 years will be as efficient as a ground to air system you could install now. The air to air systems just have lower up front install costs.
Edit: it’s 26% this year and 22% next year.
Gree has a system that claims to have full heat down to -31, so I'd say just keep researching and you'll probably be fine.
Doing a quick search, they're using 'standard' R410A refrigerant (PDF):
* https://www.greecomfort.com/assets/our-products/multi-plus-u...
the same as everyone else. It seems just that they though it worth the engineering effort to push a little further than most other companies.
See anything with the label "For Extreme Conditions":
In my case, the 99% design temperature is high single digits Fahrenheit. For the 3.5 days/year colder than that, the plan is to have the house “coast” on thermal mass.
That’s for cases where the ambient temp is below design (where the heater can make heat but just no longer enough to keep up with the building heat loss), not for when it’s below a cutoff (where the heater shuts off entirely). In my case, that’s so far below design temp that I’d expect to never see it. (We hit -9°F in 2016 and would have to go all the way back to 1943 to find a low of -14°F.) If it happened, thermal mass would start to carry us with electric space heating keeping the house from totally freezing.
I'm planning on getting rid of it altogether and doing the heat pump(s) most of the year, the wood stoves in winter and reclaiming a lot of headroom in the basement and an entire utility room that the furnace currently takes up.
> The prototype delivers 100% heating at 5°F at double the efficiency, and 70% to 80% heating at -5°F and -10°F. DOE’s Oak Ridge National Laboratory validated the performance and efficiency of Lennox’s prototype.
> Lennox is one of nine manufacturers competing in the CCHP Technology Challenge. Its product and others that meet the CCHP Technology Challenge will undergo trials in cold climate regions over the next two years to demonstrate performance, efficiency, and comfort when applied in the field throughout a winter. Deployment and commercialization are planned for 2024.
One tip from my install, is to go with single zone units. I did a multi-zone and the way the control system works is kind of weird. They also don't have as good of a turndown ratio[0] as smaller/single zone systems, making it less efficient.
Overall I'm happy with it though.