Thermoacoustic heat pumps on the verge of commercial breakthrough
pv-magazine.comFor context: https://en.wikipedia.org/wiki/Thermoacoustic_heat_engine
The company cited in the article is [Bluehart](https://blueheartenergy.com/our-technology)
One disadvantage that Bluehart lists of classic heat pumps is the need for a refrigerant fluid. But Bluehar uses helium internally; I wonder how often the helium would need to be replaced.
I thought that helium was in short supply. Would that make these things expensive? Also, I know they said it's quiet, but if the thing operates on a 60hz cycle, wouldn't that create a pervasive hum?
Yeah, I was also under the impression helium was in very short supply. The article doesn’t mention that, at all. But it does say the unit is quiet because it operates at a constant frequency, so they can use noise cancellation very effectively.