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<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Nicholas,<o:p></o:p></span></font></p>
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10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>You can certainly do that. Most newer
controllers have a “vacation” function that will provide this. Another
method is to put in a bypass to the check valve that you can open and the
system will naturally reverse thermo siphon at night. Not much in the way
of calculations other than the collectors reradiate as effectively as they
collect.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Conrad<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Cotuit Solar<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
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<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'>
re-wrenches-bounces@lists.re-wrenches.org
[mailto:re-wrenches-bounces@lists.re-wrenches.org] <b><span style='font-weight:
bold'>On Behalf Of </span></b>Nicholas Ponzio<br>
<b><span style='font-weight:bold'>Sent:</span></b> Wednesday, December 16, 2009
10:54 PM<br>
<b><span style='font-weight:bold'>To:</span></b> <st1:PersonName w:st="on">RE-wrenches</st1:PersonName><br>
<b><span style='font-weight:bold'>Subject:</span></b> [<st1:PersonName w:st="on">RE-wrenches</st1:PersonName>]
solar hot water nighttime recirc</span></font><o:p></o:p></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Apologies if this has already been discussed here.<br>
<br>
One heat diversion method I hear suggested often is recirculating through the
collectors (flatplate) at night. Are there any data, calculations or anecdotal
evidence on the effectiveness of this approach? That is, can I really radiate
as much energy back to a dark sky as I collect during the day?<br>
<br>
Thanks for any feedback.</span></font><o:p></o:p></p>
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