Thermoacoustic Refrigerator

This is my thermoacoustic refrigerator! It is a device that uses a resonating sound wave to induce a thermal gradient. I built this as part of my senior design project at the University of Portland back in 2006.

Questions or comments? Email me at

**Update** So it seems my video has garnered a lot of interest. If you are one of the many people who have emailed me and I have not responded, I apologize. I hope to respond to some of the more common questions that I have received here.

I have not made any improvements to the device nor will I for a while... other projects abound. If I was to complete the heat exchangers, I would design them as a series of parallel copper plates inside the main body of the device on either side of the stack. The plates would be threaded with copper capillary tube and would carry water (or oil) as the heat transfer medium on the hot side. Interestingly enough, I got to play with a commercial thermoacoustic refrigerator that fed high purity oxygen through the cold side to make LOX! That thing was a traveling wave device that was quite a bit more sophisticated than what I have here. You've gotta love that deep aqua-blue color of liquid oxygen!

Another question I keep on getting is how much it costs to build one of these. I spent a total of about $500 to make it, but I got a lot of free help from some very kind people. Knowing what I know now, I am confident that I could make a much better one for even cheaper, but the most expensive component would be the noble gas working fluid. Helium is pricey stuff and likes to leak...

Public literature in the field of thermoacoustics is very limited from what I found. If you have access to a university library white paper database, published white papers on the the subject abound!

Thank you all and I will try to respond to more questions when I get the opportunity.

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