Sub-zero heat pump challenge delivers new tech – and a fresh blow to gas (Rachel Williamson 10 January 2024, Renew Economy)

Four more prototypes are now out of the lab and onto the US Department of Energy’s list of heat pumps that can operate in sub-zero conditions without resorting to gas backup. […]

Bosch, Daikin, Midea, and Johnson Controls join Lennox International, Carrier, Trane Technologies, and Rheem in the next phase of the challenge, where their prototypes will be installed at some 23 locations in the US and Canada and monitored over the next year.

The program has pushed companies into markets they may not have originally designed for.

For example, Bosch’s new IDS Ultra heat pump is the company’s first air-to-air heat pump designed specifically for colder climates.

Bosch says it can keep operating in temperatures down to -15°C and still function at -25°C.