<html><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:12pt">Alan,<br><br>Forgot to mention that those thermoelectric modules can be pulse width modulated to make their current drain much more manageable and still accomplish climate and humidity control. There would be a fan needed on the air side, and the other could be directly attached to the steel hull with thermal grease. That would make a very efficent heat/cold sink, and eliminate another fan. There are comercial pic controlers on Evil-Bay for under $50, or if your handy with a soldering iron, you can make your own.<br><br>Keith<br><div><span><br></span></div><div style="display: block;" class="yahoo_quoted"> <br> <br> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 12pt;"> <div style="font-family: HelveticaNeue, Helvetica Neue,
 Helvetica, Arial, Lucida Grande, sans-serif; font-size: 12pt;"> <div dir="ltr"> <font face="Arial" size="2"> On Wednesday, March 5, 2014 8:05 PM, Joe Perkel <josephperkel@yahoo.com> wrote:<br> </font> </div>  <div class="y_msg_container"><div id="yiv2628794219"><div><div>Yes, very interesting. I also have a more than passing interest in climate control.</div><div><br clear="none"></div><div>Joe<br clear="none"><br clear="none"></div><div class="yiv2628794219yqt9357239435" id="yiv2628794219yqt01943"><div><br clear="none">On Mar 5, 2014, at 10:50 PM, Alan James <<a rel="nofollow" shape="rect" ymailto="mailto:alanlindsayjames@yahoo.com" target="_blank" href="mailto:alanlindsayjames@yahoo.com">alanlindsayjames@yahoo.com</a>> wrote:<br clear="none"><br clear="none"></div><blockquote type="cite"><div><div style="color:#000;background-color:#fff;font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande,
 sans-serif;font-size:10pt;"><div><span>Thanks Keith,</span></div><div style="color:rgb(0, 0, 0);font-size:13.333333969116211px;font-family:HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif;background-color:transparent;font-style:normal;"><span>that's an encouragement to know that they operate them on a large scale</span></div><div style="color:rgb(0, 0, 0);font-size:13.333333969116211px;font-family:HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif;background-color:transparent;font-style:normal;"><span>like that.</span></div><div style="color:rgb(0, 0, 0);font-size:13.333333969116211px;font-family:HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif;background-color:transparent;font-style:normal;"><span>Alan</span></div><div><br clear="none"></div>  <div style="font-family:HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif;font-size:10pt;">
 <div style="font-family:HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif;font-size:12pt;"> <div dir="ltr"> <hr size="1">  <font face="Arial" size="2"> <b><span style="font-weight:bold;">From:</span></b> keith tollett <<a rel="nofollow" shape="rect" ymailto="mailto:k6fee@yahoo.com" target="_blank" href="mailto:k6fee@yahoo.com">k6fee@yahoo.com</a>><br clear="none"> <b><span style="font-weight:bold;">To:</span></b> Personal Submersibles General Discussion <<a rel="nofollow" shape="rect" ymailto="mailto:personal_submersibles@psubs.org" target="_blank" href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>> <br clear="none"> <b><span style="font-weight:bold;">Sent:</span></b> <br clear="none"> <b><span style="font-weight:bold;">Subject:</span></b> Re: [PSUBS-MAILIST] Thermoelectric air conditioning<br clear="none"> </font> </div> <div class="yiv2628794219y_msg_container"><br
 clear="none"><div id="yiv2628794219"><div><div style="color:rgb(0, 0, 0);background-color:rgb(255, 255, 255);font-family:HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif;font-size:12pt;">Alan,<br clear="none"><br clear="none">U.S. Military subs use this for climate control. Don't want any noxious refrigerants loose in a closed environment. No moving parts, though they do eat a lot of power (not an issue on nuke boats).<br clear="none"><br clear="none">Keith<br clear="none"><div><span><br clear="none"></span></div><div class="yiv2628794219yqt3103009485" id="yiv2628794219yqt19033"><div class="yiv2628794219yahoo_quoted" style="display:block;"> <br clear="none"> <br clear="none"> <div style="font-family:HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif;font-size:12pt;"> <div style="font-family:HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif;font-size:12pt;"> <div
 dir="ltr"> <font face="Arial" size="2"> On Wednesday, March 5, 2014 6:22 PM, Marc de Piolenc <<a rel="nofollow" shape="rect" ymailto="mailto:piolenc@archivale.com" target="_blank" href="mailto:piolenc@archivale.com">piolenc@archivale.com</a>> wrote:<br clear="none"> </font> </div>
  <div class="yiv2628794219y_msg_container">There's an active discussion of Peltier devices ongoing on the
 other <br clear="none">personal submersibles mailing list <br clear="none">(<a rel="nofollow" shape="rect" ymailto="mailto:international_psubs_minisubs@yahoogroups.com" target="_blank" href="mailto:international_psubs_minisubs@yahoogroups.com">international_psubs_minisubs@yahoogroups.com</a>). You might want to join it.<br clear="none"><br clear="none">Quick points: you still need some way to dump heat outside the boat, <br clear="none">otherwise you're just moving heat from one point you want to cool, to <br clear="none">another that can't afford to get any hotter. And of course the Peltier <br clear="none">device produces heat of its own.<br clear="none">Which leads to the second key point, namely that there is an optimum <br clear="none">current for heat pumping, and for some reason the manufacturers <br clear="none">routinely rate their modules for a voltage that gives a higher current, <br clear="none">and thus poor heat pumping efficiency. You
 have to learn certain key <br clear="none">characteristics of your unit and come up with your own rating. The unit <br clear="none">I fooled with back in the States was rated at 12 volts, but worked much <br clear="none">better with an 8-ohm resistor in series.<br clear="none"><br clear="none">Marc de Piolenc<br clear="none"><br clear="none">On 3/6/2014 9:08 AM, Alan James wrote:<br clear="none">> Hi Psubbers,<br clear="none">> Has anyone looked at thermoelectric coolers (peltier devices) for air<br clear="none">> conditioning / dehumidifying & heating.<br clear="none">> I'm hopeful someone might be able to save me a bit of research.<br clear="none">> <a rel="nofollow" shape="rect" target="_blank" href="http://en.wikipedia.org/wiki/Thermoelectric_cooling">http://en.wikipedia.org/wiki/Thermoelectric_cooling</a><br clear="none">> For those who aren't familiar, they are normally used to cool small<br clear="none">> units like
 computers, electrical cabinets & chili
 bins.<br clear="none">> They are about 1&1/2" square & 1/8"  thick with two wires coming off them.<br clear="none">> The unit I have is 60W & operates off 12-15V. When powered up, one side<br clear="none">> gets hot & the other cold.<br clear="none">> The cooling effectiveness is regulated by how well you can dissipate the<br clear="none">> heat from the hot side.<br clear="none">> In the submersible application the hull can act as the heat sink. By<br clear="none">> switching polarity you have a heater.<br clear="none">> The down side is that you use about 3 times more power for cooling than<br clear="none">> traditional refrigeration units,<br clear="none">> however an air conditioning unit is bulky, & it would be a trade off<br clear="none">> between the additional battery size & expense<br clear="none">> to run the peltier cooler as apposed to the bulk & expense of an air<br
 clear="none">> conditioning unit & it's associated through<br clear="none">> hull heat exchange unit .<br clear="none">> The heating faze is more economical.<br clear="none">> G.L. require air conditioning & humidity control in submersibles.<br clear="none">> Thanks<br clear="none">> Alan<br clear="none">><br clear="none">><br clear="none">> _______________________________________________<br clear="none">> Personal_Submersibles mailing list<br clear="none">> <a rel="nofollow" shape="rect" ymailto="mailto:Personal_Submersibles@psubs.org" target="_blank" href="mailto:Personal_Submersibles@psubs.org">Personal_Submersibles@psubs.org</a><br clear="none">> <a rel="nofollow" shape="rect" target="_blank" href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a><br clear="none">><br clear="none"><br clear="none">-- <br
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