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I have a bit of an ambitious project on hand and was looking for some advice/ideas.

My team and I are working on a project that involves retrofitting a commercial grade freezer (model MasterBilt IHC-48) into an environment chamber that would be used for HASS testing. HASS testing involves perform a rapid temperature cycling test and vibration/shock test, which would be used to stress electronic products.

As an example this rapid temperature cycling might involve going from +65C to -10C in 2 minutes and vice versa.

The medium inside the chamber would be air. The dimensions inside the freezer are 27"x58"x46" (0.686m X 1.47m X 1.17m).

The gray area for me is how to achieve this rapid cooling. What I am looking for are ideas/suggestions on how to retrofit this freezer to achieve this rapid cooling.

Any ideas/comments are welcomed.

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  • $\begingroup$ Cooling a little over a cubic meter of air by 75K in 2 minutes requires on the order of 1 kW of average continuous heat transfer. It might be simpler to consider having two reservoirs of air, one hot and one cold, and using fans to transfer air from one reservoir or the other to the test chamber. $\endgroup$ – Dave Tweed Dec 30 '15 at 16:25
  • $\begingroup$ That's an interesting idea. In your plan, would this require the cooling system to be constantly be running in preparation for expected use. And again with your plan would the rapid temperature changes be possible to achieve? $\endgroup$ – MHKK Dec 30 '15 at 16:59
  • $\begingroup$ Yes, and yes. Continuous operation spreads the workload out over a longer period of time, requiring a lower-powered chiller. Rapid temperature changes would depend only on how fast you can move the air. $\endgroup$ – Dave Tweed Dec 30 '15 at 17:07
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    $\begingroup$ This is not a forum for brainstorming or general feedback on open-ended design problems. You have a design problem: Come up with a design. If there's a specific reason your design isn't working or workable and you're unable to find a solution, then you may have a question that fits our scope. Once you earn a small amount of reputation you'll be able to have conversations, get feedback, brainstorm, etc. in our Engineering Chat. $\endgroup$ – Air Dec 30 '15 at 17:55
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    $\begingroup$ I voted to close this question for the same reasons @Air gave - an unbounded design problem has no "correct" answer so none can ever be selected, leaving this question in SE purgatory. $\endgroup$ – Chuck Jan 2 '16 at 10:07
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Cooling a little over a cubic meter of air by 75K in 2 minutes requires on the order of 1 kW of average continuous heat transfer. It might be simpler to consider having two reservoirs of air, one hot and one cold, and using fans to transfer air from one reservoir or the other to the test chamber.

Continuous operation spreads the workload out over a longer period of time, requiring a lower-powered chiller. Rapid temperature changes would depend only on how fast you can move the air.

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  • $\begingroup$ Consider also compressing the air before cooling it. In addition to reducing the size of its storage, it will also cool further on expanding into the test chamber. $\endgroup$ – Brian Drummond Jan 8 '17 at 16:22

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