<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "> The reason to use a drain-back system is to not have the mass of fluid in the collector get so cold overnight.<div>The collector will, of course, be ice-cherry-cold, but it should warm-up faster when empty. I am setting up a</div><div>system where I intend to drain-back into a 1,000 gal tank, skipping the heat exchanger. </div><div>The concrete tank is enclosed in 10"+ of foam, in the hope of year-round storage. </div><div> Question: What could I use to suppress possible organisms from growing in that hot, dark soup? Vinegar? Clorox? </div><div>The water will remain in that unpressurized system: domestic heat & water will be through heat exchangers in the tank.</div><div><br></div><div><div apple-content-edited="true">
<span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0; "><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; "><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; "><div>Clarke Olsen</div><div>373 route 203</div><div>Spencertown, NY 12165 </div><div>USA</div><div>518-392-4640</div><div><a href="mailto:colsen@fairpoint.net">colsen@fairpoint.net</a></div><div><br></div></span><br class="Apple-interchange-newline"></span><br class="Apple-interchange-newline"></span>
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<br><div><div>On Mar 14, 2012, at 8:43 PM, Nick Pyner wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite">
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<div><span class="703034723-14032012"><font face="Arial" color="#0000ff" size="2">Not to
me. </font></span></div>
<div> </div>
<div><span class="703034723-14032012"></span><font face="Arial"><font color="#0000ff"><font size="2">I don't know anything about drain back systems but my understanding is that:</font></font></font></div>
<div><font face="Arial"><font color="#0000ff"><font size="2"></font></font></font> </div>
<div><font><font><font face="Arial"><font color="#0000ff"><font size="2"><span class="703034723-14032012">1. </span>I<span class="703034723-14032012">f you use a
closed loop glycol collector, you don't need drain
back</span></font></font></font></font></font></div>
<div><font><font><font face="Arial"><font color="#0000ff"><font size="2"><span class="703034723-14032012"></span></font></font></font></font></font> </div>
<div><font><font><font face="Arial"><font color="#0000ff"><font size="2"><span class="703034723-14032012">2, If you just use water, you drain the water and
refill it the next morning - with water , which I guess goes quite soem
way to explain why people use
glycol.</span></font></font></font></font></font></div>
<div><font><font><font face="Arial"><font color="#0000ff"><font size="2"><span class="703034723-14032012"></span></font></font></font></font></font> </div>
<div><font><font><font face="Arial"><font color="#0000ff"><font size="2"><span class="703034723-14032012">In the article alluded
to</span></font></font></font></font></font></div>
<div><font><font><font face="Arial"><font color="#0000ff"><font size="2"><span class="703034723-14032012"></span></font></font></font></font></font> </div>
<div><font><font><font face="Arial"><font color="#0000ff"><font size="2"><span class="703034723-14032012">1. They don't seem to draw any distinction between open
and closed loop systems. </span></font></font></font></font></font></div>
<div><font><font><font face="Arial"><font color="#0000ff"><font size="2"><span class="703034723-14032012"></span></font></font></font></font></font> </div>
<div><font><font><font face="Arial"><font color="#0000ff"><font size="2"><span class="703034723-14032012">2. they glibly talk about an oversized heat exchanger.
This may be detrimental to the heat exchanger performing its prime function -
namely, exchanging heat.</span></font></font></font></font></font></div>
<div><font><font><font face="Arial"><font color="#0000ff"><font size="2"><span class="703034723-14032012"></span></font></font></font></font></font> </div>
<div><font><font><font face="Arial"><font color="#0000ff"><font size="2"><span class="703034723-14032012">3. It seems that they must have air in the circlation
system. This would be fatal to collector
efficiency</span></font></font></font></font></font></div>
<div><font><font><font face="Arial"><font color="#0000ff"><font size="2"><span class="703034723-14032012"></span></font></font></font></font></font> </div>
<div><font><font><font face="Arial"><font color="#0000ff"><font size="2"><span class="703034723-14032012">4. The actual collector must be the worst design ever.
I have never actually seen a serpentine design like that in actual production.
The only place where you would see anything like that is in an article
showing how not to do it. </span></font></font></font></font></font></div>
<div><font><font><font face="Arial"><font color="#0000ff"><font size="2"><span class="703034723-14032012"></span></font></font></font></font></font> </div>
<div><font><font><font face="Arial"><font color="#0000ff"><font size="2"><span class="703034723-14032012"> Even if there is no need to distinguish between
open and close loop systems, and the heat exchanger is OK, and they have some
secret air relief device, who on earth would take Wagner Solar seriously, when
they have a collector like
that? </span></font></font></font></font></font></div>
<div><font><font><font face="Arial"><font color="#0000ff"><font size="2"><span class="703034723-14032012"></span></font></font></font></font></font> </div>
<div><font><font><font face="Arial"><font color="#0000ff"><font size="2"><span class="703034723-14032012">I don't know who the smiling guys are at the top of the
page, but they could certainly do with asking some questions. Maybe they are
just salesmen quoting a press
handout. </span></font></font></font></font></font></div>
<div><font><font><font face="Arial"><font color="#0000ff"><font size="2"><span class="703034723-14032012"></span></font></font></font></font></font> </div>
<div><span class="703034723-14032012"></span><font face="Arial"><font color="#0000ff"><font size="2">A<span class="703034723-14032012">nd another thing. Why
would you use a second heat exchanger system for backup? Surely it is simpler to
just install an electric element at the bottom of the tank like everybody else
does? </span></font></font></font><br></div><p><font size="2">Nick Pyner<br><br>Dee Why NSW </font></p>
<blockquote>
<div class="OutlookMessageHeader" dir="ltr" align="left"><font face="Tahoma" size="2">-----Original Message-----<br><b>From:</b>
<a href="mailto:greenbuilding-bounces@lists.bioenergylists.org">greenbuilding-bounces@lists.bioenergylists.org</a>
[mailto:greenbuilding-bounces@lists.bioenergylists.org]<b>On Behalf Of
</b>Sacie Lambertson<br><b>Sent:</b> Wednesday, 14 March 2012 7:06
AM<br><b>To:</b> Greenbuilding<br><b>Subject:</b> [Greenbuilding] new solar
heating system in this country<br><br></font></div><font size="+0"><font face="verdana,sans-serif">This sounds very good to me:<br><br><a href="http://www.buildinggreen.com/live/index.cfm/2012/3/13/German-Innovation-in-Solar-Water-Heating">http://www.buildinggreen.com/live/index.cfm/2012/3/13/German-Innovation-in-Solar-Water-Heating</a><br></font></font></blockquote></div>
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