Good luck getting approval for propane as a refrigerant in the US. I think it's recently got approved for small systems like 5k BTU or less but that's a really small window unit. (Sealed units that can never be serviced, this making more waste)
When the whole cfc ozone thing was the "crisis of the the moment" it was already known that propane was an excellent refrigerant and could have replaced r12/r22 in most applications with no modifications. Did we do that? Nope, we doubled down are more regulations for more expensive systems, because money!!!! and who cares if the new refrigerants have a greater overall environmental impact. If they used something simple, cheap and readily available like propane they could stop people from using these older units or from continuing to service them themselves.
The article describes this as a "monobloc" air-to-water heat pump. Monobloc means that the compressor, fan, and all the refrigerant are entirely sealed within the outdoor unit, and it just sends a loop of water (or water w/ glycol in it) into the house, where it can warm or cool an insulated buffer tank that effectively stores the hot or cold water for use in heating, cooling, and domestic hot water.
> The new product utlizes propane refrigerant with a lower global warming potential and has a seasonal coefficient of performance (SCOP) of over 5. According to the manufacturer, it can achieve a flow temperature of 75 C and 100% heating output at outside temperatures of -15 C.
> This final action modifies the use conditions required for use of three flammable refrigerants—isobutane (R-600a), propane (R-290), and R-441A—in new household refrigerators, freezers, and combination refrigerators and freezers under the Significant New Alternatives Policy (SNAP) program. The use conditions, which address safe use of flammable refrigerants, are being revised to reflect the updated UL Standard 60335-2-24 that is incorporated by reference.
Buried at the bottom, I found this interesting. Any details on how it works? Could you just store compressed refrigerant in a tank for later use?
> The manufacturer said the heat pump can also be integrated with energy storage systems (ESS) to maximize the use of residential PV systems.
“Surplus energy can be stored in the ESS battery and diverted to the AWHP’s integrated water tank during the daytime, when solar energy production is at its peak,” it explained. “In the evening, when energy consumption is typically high, the ESS utilizes the stored energy to provide hot water and to power home appliances, boosting energy efficiency and energy self-reliance.”
When the whole cfc ozone thing was the "crisis of the the moment" it was already known that propane was an excellent refrigerant and could have replaced r12/r22 in most applications with no modifications. Did we do that? Nope, we doubled down are more regulations for more expensive systems, because money!!!! and who cares if the new refrigerants have a greater overall environmental impact. If they used something simple, cheap and readily available like propane they could stop people from using these older units or from continuing to service them themselves.