It can operate efficiently at lower temps. Current air source heat pumps see degraded performance and below freezing temps and will not be able to effectively heat a home at the lowest temps that can occur in the northern hemisphere.
Thanks. But I’m trying to figure out how they do that.
The "secret sauce" of the increased efficiency is that they're using thermoacoustics, which previously had been a technology used in one-off applications with a large budget (e.g. the James Webb telescope uses it to stay cool). Prior to now there were no manufacturers providing the technology to be widely available at scale.