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.
Brad On Tue, Jun 17, 2025 at 7:31 AM jay via RE-wrenches < [email protected]> wrote: > 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. > > Which means please let me know of a good resource for solar thermal > products. > Specifically I need to convert this to a drain back system. > I’ll need the drain back tank and new pump station > > thanks > > jay > > On Jun 15, 2025, at 8:35 PM, Bradley Bassett via RE-wrenches < > [email protected]> wrote: > > 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. > > Brad Bassett > > On Sun, Jun 15, 2025 at 5:02 PM david quattro via RE-wrenches < > [email protected]> wrote: > >> There must be a variable mixing valve that is informed and controlled by >> a thermocouple >> >> >> >> On Sun, Jun 15, 2025 at 4:46 PM Jay via RE-wrenches < >> [email protected]> wrote: >> >>> Hi all >>> >>> I’ve inherited an incorrectly sized solar thermal evacuated tube system. >>> It’s too many tubes for the use most of the year. >>> >>> Does anyone know of a design or product that can remotely cover them? >>> I can find shade cloth of course that I can cover them but something >>> remote control would be better >>> >>> Thx >>> Jay >>> >>> > _______________________________________________ > List sponsored by Redwood Alliance > > Pay optional member dues here: http://re-wrenches.org > > List Address: [email protected] > > 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/[email protected]/ > 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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