<div dir="ltr">I would hesitate to do drain back with evacuated tube collectors, I think they can severely overheat if cooling is not always available. The heat diversion method is automatic, I have not touched mine in decades. <div><br></div><div>Brad</div></div><br><div class="gmail_quote gmail_quote_container"><div dir="ltr" class="gmail_attr">On Tue, Jun 17, 2025 at 7:31 AM jay via RE-wrenches <<a href="mailto:re-wrenches@lists.re-wrenches.org">re-wrenches@lists.re-wrenches.org</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div>All of these options would be possible for someone younger and able, but the client is early 80’s and she wants it to work correctly without having to do the manual cover/uncover which given the collector area, elevation and temps etc isn’t an option. <div><br></div><div>Which means please let me know of a good resource for solar thermal products. </div><div>Specifically I need to convert this to a drain back system. </div><div>I’ll need the drain back tank and new pump station </div><div><br></div><div>thanks</div><div><br></div><div>jay<br><div><div><br><blockquote type="cite"><div>On Jun 15, 2025, at 8:35 PM, Bradley Bassett via RE-wrenches <<a href="mailto:re-wrenches@lists.re-wrenches.org" target="_blank">re-wrenches@lists.re-wrenches.org</a>> wrote:</div><br><div><div dir="ltr">When I found that my system was somewhat oversized, I plumbed in a mixing valve and a heat dump radiator (a few Cu pipes) in the crawl space to dump the heat. It's on the solar supply line and it works like a charm. It actually adds a very modest amount of heat to the crawl space, not enough to notice. It's going on 20 years without any issues, probably because it's an anti-freeze system so no mineral buildup in the mixing valve. I've also heard of using a fin radiator under the eve for this instead of the crawl space. The crawl space was easier for me. <div><br></div><div>Brad Bassett</div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Sun, Jun 15, 2025 at 5:02 PM david quattro via RE-wrenches <<a href="mailto:re-wrenches@lists.re-wrenches.org" target="_blank">re-wrenches@lists.re-wrenches.org</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="auto">There must be a variable mixing valve that is informed and controlled by a thermocouple</div><div dir="auto"><br></div><div dir="auto"><br></div><div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Sun, Jun 15, 2025 at 4:46 PM Jay via RE-wrenches <<a href="mailto:re-wrenches@lists.re-wrenches.org" target="_blank">re-wrenches@lists.re-wrenches.org</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">Hi all<br>
<br>
I’ve inherited an incorrectly sized solar thermal evacuated tube system. <br>
It’s too many tubes for the use most of the year. <br>
<br>
Does anyone know of a design or product that can remotely cover them? <br>
I can find shade cloth of course that I can cover them but something remote control would be better <br>
<br>
Thx<br>
Jay<br>
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