I remember reading about thermoacoustic devices 20 years ago, probably from the following article: https://www.popsci.com/scitech/article/2004-05/chilling-sound

I remember reading about thermoacoustic devices 20 years ago, probably from the following article: https://www.popsci.com/scitech/article/2004-05/chilling-sound-waves-not-freon/ https://www.popsci.com/scitech/article/2004-05/chilling-soun... I think the reason that they haven't seen adoption isn't that they're a scam, but rather because they're more expensive than traditional approaches (not quite sure why, or by what margins). However, since our attempts to replace freon with ever-more-exotic refrigerants seems to inevitably fall face-first into environmental disaster, it's possible that a non-greenhouse-gas approach could be regulated/subsidized into existence, if it's not too much more expensive.