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</o:shapelayout></xml><![endif]--></head><body lang=EN-CA link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US'>During the winter some people prefer infra-red heaters in their homes to directly warm the occupants. This is considered to be more efficient than heating up air and then forcing it into the living space. Similarly, perhaps several peltiers could be placed on the sub pilots person to directly cool him in the otherwise warm air environment? A set of cooling headband, wristbands, and leg/foot wraps to cool the blood where it is close to the surface of the body? You only need cooling while the sub is on or close to the surface.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US'>Tim<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri",sans-serif'>From:</span></b><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri",sans-serif'> Personal_Submersibles [mailto:personal_submersibles-bounces@psubs.org] <b>On Behalf Of </b>Alan via Personal_Submersibles<br><b>Sent:</b> Monday, August 14, 2017 12:08 AM<br><b>To:</b> personal_submersibles@psubs.org<br><b>Subject:</b> [PSUBS-MAILIST] Peltier Airconditioner<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal>Have looked in to this a bit more.<o:p></o:p></p></div><div><p class=MsoNormal>An average compression type car air conditioner takes about 3000W <o:p></o:p></p></div><div><p class=MsoNormal>of power to run. Cooling with peltiers requires 4x this power to get the<o:p></o:p></p></div><div><p class=MsoNormal>equivalent effect. So 12000W required to keep up with a car air conditioner!<o:p></o:p></p></div><div><p class=MsoNormal>Peltiers have a typical maximum difference in temperature from one side<o:p></o:p></p></div><div><p class=MsoNormal>to the other of 70C, but to run at maximum efficiency it is recommended <o:p></o:p></p></div><div><p class=MsoNormal>to keep the temperature difference at less than 30C. So this would mean<o:p></o:p></p></div><div><p class=MsoNormal>a peltier rated 72W should be run at around 30W. <o:p></o:p></p></div><div><p class=MsoNormal>The efficiency also depends on how well you can remove the heat from<o:p></o:p></p></div><div><p class=MsoNormal>the hot side, as if it gets too hot the heat build up can migrate across to the <o:p></o:p></p></div><div><p class=MsoNormal>cold side.<o:p></o:p></p></div><div><p class=MsoNormal>A 1&1/2 x 1&1/2" peltier may be around 72W (12V & 6 A) & cost US $3:61<o:p></o:p></p></div><div><p class=MsoNormal>Deal Extreme with free shipping....<o:p></o:p></p></div><div><p class=MsoNormal><a href="http://m.dx.com/p/tec1-12706-semiconductor-thermoelectric-cooler-peltier-white-157283?stiff=99">http://m.dx.com/p/tec1-12706-semiconductor-thermoelectric-cooler-peltier-white-157283?stiff=99</a><o:p></o:p></p></div><div><p class=MsoNormal>So to get the same cooling as your car air conditioner you need 166 of these <o:p></o:p></p></div><div><p class=MsoNormal>& that's running them at full power & not the more economical half power.<o:p></o:p></p></div><div><p class=MsoNormal> I have read that a peltier air conditioner can drop a cars temperature to 20C<o:p></o:p></p></div><div><p class=MsoNormal>below ambient, but I don't have any specs on the unit they mention.<o:p></o:p></p></div><div><p class=MsoNormal> I am going to persevere with them as I am building a small one person sub<o:p></o:p></p></div><div><p class=MsoNormal>& I like that I can make a dehumidifyer, airconditioner & heater all in one & take<o:p></o:p></p></div><div><p class=MsoNormal>up little room. As discussed, their heating efficiencies are great, so if you look<o:p></o:p></p></div><div><p class=MsoNormal>at them as a descent heater with the spin off of some cooling benefit then they<o:p></o:p></p></div><div><p class=MsoNormal>don't look so bad! Battery technology is leaping forward, so I am anticipating that<o:p></o:p></p></div><div><p class=MsoNormal>their power drain won't be such a big deal by the time I get around to buying<o:p></o:p></p></div><div><p class=MsoNormal>batteries.<o:p></o:p></p></div><div><p class=MsoNormal>Cheers Alan<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal style='margin-bottom:12.0pt'><o:p> </o:p></p><div><p class=MsoNormal>Sent from my iPad<o:p></o:p></p></div></div></div></body></html>