Wrenches, Jay, Get a second tank, even a stock tank (for livestock) get some soft copper tube coil it aground the bottom and get a circ pump and a thermostat pump water from the solar tank to the "bonus" tank as a load dump, it can even be a old style pressure tank "no bladder" just to dump the heat into non insulated open or closed, over the night it will cool off and be ready for the next day.
On Tue, Jun 17, 2025, 3:22 PM Luke Christy via RE-wrenches < re-wrenches@lists.re-wrenches.org> wrote: > Hi Jay, > I agree with Brad that Evacuated tubes are not a good (or even a > reasonably possible) candidate for a drainback retrofit. If they are > pass-through tubes, then they cannot fully drain as piping connections > typically come through header connections at the tops of the tubes. If they > are sealed heat-pipe tubes, then not only is the header unlikely to drain > properly, but the tubes themselves will stagnate at a very high temperature > without heat transfer fluid flow. > > I recommend a diversion heat- dump arrangement such as Todd suggests.Use > paralleled runs of conventional hot water baseboard fin tube for the heat > dissipator. This stuff is readily available at almost every plumbing supply > house and it works well. > > Diversion can be activated by either an electric 3-way valve and a set > point controller, or the passive wax-thermostat 3-way valve that you > mention. I have used both methods extensively with good results. The wax > thermostat will probably be significantly harder to find. Some years ago I > ordered them through Low Energy Systems in Denver. Reach out to me off list > and and I can supply some contact information. > > -Luke > > Luke Christy > Renewable energy consultant > > NABCEP Certified PV Installation Professional™: > > Solar Gain Services, LLC > PO Box 531 > Monte Vista, CO 81144 > 719.588.3044 > sgsrenewab...@gmail.com > > > > On Jun 17, 2025, at 3:46 PM, jay via RE-wrenches < > re-wrenches@lists.re-wrenches.org> wrote: > > In doing research today I found the following, not sure where I can buy > them at this point. > > 1. solar dissipation tubes. that will do about 12,000 btu or at least > this one does. > > 2. 3 way thermostatic valve which uses a type of wax that opens and closes > it at a specific temp and routes the heat through the dissipation tube vs > the heat exchanger down below. > > > _______________________________________________ > List sponsored by Redwood Alliance > > Pay optional member dues here: http://re-wrenches.org > > List Address: RE-wrenches@lists.re-wrenches.org > > Change listserver email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > There are two list archives for searching. When one doesn't work, try the > other: > https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/ > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > http://www.re-wrenches.org/etiquette.htm > > Check out or update participant bios: > http://www.members.re-wrenches.org > >
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