5 ms·

Kinda fuzzy on how this works/what the tradeoffs are? Looks like it's creating a standing pressure wave and then tapping into the colder or hotter part as appr

Kinda fuzzy on how this works/what the tradeoffs are? Looks like it's creating a standing pressure wave and then tapping into the colder or hotter part as appropriate? Based on the diagrams it seems like it would need a radiator or something for larger surface area? Also curious as to how loud it is.

stubish 4y ago
Per the article: "Equium claims that the heat pump system is completely silent, despite the use of a speaker to generate the acoustic wave. The level of noise is reportedly lower than 30 dB – the equivalent of a whisper."
hasmanean 4y ago
It’s been known for a long time, but sort of vanished off the radar for much of this century. I can only imagine it’s because it has applications as “mixture separators” as this webpage shows https://www.lanl.gov/org/ddste/aldps/materials-physics-applications/condensed-matter-magnet-science/thermoacoustics/index.php https://www.lanl.gov/org/ddste/aldps/materials-physics-appli... and so it could be used to enrich uranium (in the form of uranium hexaflouride gas), in a more robust way than the stupid legacy centrifuge technology. Thus all the interesting research on it must have been classified.
arsalanb 4y ago
It uses the acoustic wave to expand and contract pressurized helium, and then conduct heat created from the subsequent pressure oscillation. Source: https://www.pv-magazine.com/2023/01/02/residential-thermo-acoustic-heat-pump-produces-water-up-to-80-c https://www.pv-magazine.com/2023/01/02/residential-thermo-ac... Which I just noticed was posted a few hours ago, here: https://news.ycombinator.com/item?id=34233719 https://news.ycombinator.com/item?id=34233719
twobitshifter 4y ago
Same question about how loud it is. Wikipedia says thermoacoustic engines work at 180db, which is the sound of a pound of TNT being detonated 15 feet away.
- pjerem 4y ago
  > 180db, which is the sound of a pound of TNT being detonated 15 feet away. Sounds like that can be a bit annoying
  - elliottkember 4y ago
    Fortunately, they're only annoying for a very short time
    - brnt 4y ago
      Plus, it'll be the last time ever you hear anything annoying at all.
      - magnetic 4y ago
        Not quite. After an acoustic trauma, especially bad enough to degrade your hearing, there is a good chance you will be gifted with life-long Tinnitus.
        missedthecue 4y ago
        I think he's insinuating you're getting blown up. Guaranteed tinnitus cure
        hinkley 4y ago
        It can also stop your heart.
  - _eht 4y ago
    And warm!
- dcroley 4y ago
  Equium claims that the heat pump system is completely silent, despite the use of a speaker to generate the acoustic wave. The level of noise is reportedly lower than 30 dB – the equivalent of a whisper. “The sound our system produces stays confined inside the core, so you cannot hear it from outside,” said Loyer.

stubish 4y ago

Per the article: "Equium claims that the heat pump system is completely silent, despite the use of a speaker to generate the acoustic wave. The level of noise is reportedly lower than 30 dB – the equivalent of a whisper."

hasmanean 4y ago

It’s been known for a long time, but sort of vanished off the radar for much of this century. I can only imagine it’s because it has applications as “mixture separators” as this webpage shows https://www.lanl.gov/org/ddste/aldps/materials-physics-applications/condensed-matter-magnet-science/thermoacoustics/index.php https://www.lanl.gov/org/ddste/aldps/materials-physics-appli... and so it could be used to enrich uranium (in the form of uranium hexaflouride gas), in a more robust way than the stupid legacy centrifuge technology. Thus all the interesting research on it must have been classified.

arsalanb 4y ago

It uses the acoustic wave to expand and contract pressurized helium, and then conduct heat created from the subsequent pressure oscillation. Source: https://www.pv-magazine.com/2023/01/02/residential-thermo-acoustic-heat-pump-produces-water-up-to-80-c https://www.pv-magazine.com/2023/01/02/residential-thermo-ac... Which I just noticed was posted a few hours ago, here: https://news.ycombinator.com/item?id=34233719 https://news.ycombinator.com/item?id=34233719

twobitshifter 4y ago

Same question about how loud it is. Wikipedia says thermoacoustic engines work at 180db, which is the sound of a pound of TNT being detonated 15 feet away.

pjerem 4y ago
> 180db, which is the sound of a pound of TNT being detonated 15 feet away. Sounds like that can be a bit annoying
- elliottkember 4y ago
  Fortunately, they're only annoying for a very short time
  - brnt 4y ago
    Plus, it'll be the last time ever you hear anything annoying at all.
    - magnetic 4y ago
      Not quite. After an acoustic trauma, especially bad enough to degrade your hearing, there is a good chance you will be gifted with life-long Tinnitus.
      - missedthecue 4y ago
        I think he's insinuating you're getting blown up. Guaranteed tinnitus cure
      - hinkley 4y ago
        It can also stop your heart.
- _eht 4y ago
  And warm!
dcroley 4y ago
Equium claims that the heat pump system is completely silent, despite the use of a speaker to generate the acoustic wave. The level of noise is reportedly lower than 30 dB – the equivalent of a whisper. “The sound our system produces stays confined inside the core, so you cannot hear it from outside,” said Loyer.