<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto"><div></div><div>Brian,</div><div>I have done a bit of experimentation with cooling other components like</div><div>large LEDs & high powered mosfets, & certainly water is the best option.</div><div>If the peltiers are mounted against the hull tightly & below the water line I don't</div><div>think an external heat sink would be necessary.</div><div>With the LEDs it is important to screw them tight to a smooth flat</div><div>heat sink with a smear of heat transfer paste, or they burn out pretty quickly.</div><div>Good point about the paint. Depending on how thick it is. If you have an </div><div>Infrared thermometer ( great tool) you (or I ) could measure the cool side</div><div>of the peltier against a painted & unpainted metal surface. I will hunt around</div><div>& see what scraps of metal I have.</div><div>The cold side should be less cold if the heat is not being transferred from the other side.</div><div> Alec says that he doesn't think anything would have had much impact on</div><div>the high temperatures generated in the sub. Perhaps some sort of exostructure</div><div>or fibreglass shell that protects the hull from direct sunlight. Or reflective</div><div>paint top side?</div><div>Alan</div><div><br></div><div><br></div><div><br></div><div><br></div><div><br>On 4/04/2019, at 1:43 AM, Brian Hughes via Personal_Submersibles <<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>> wrote:<br><br></div><blockquote type="cite"><div>
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... and will the hull be a sufficient heat sink given the paint which insulates? Maybe one of the aluminum heat sinks that come with the peltier kits from China, one of the long flat ones, attached outside the hull opposite the inside chips.
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Larry Niven's SF book "Ringworld" came to mind as that's how the engineers cooled their structure, big fins stuck out into space. Not an engineer, but I've stayed at certain hotels and knew Poul Anderson. :-)<br>
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