We have used Seltrol 112 as an inhibitor in large unpressurized drainback systems based on a recommendation from Holocene.
I have previously worked on large unpressurized systems from other installers and not seen any issues with their tap water-only systems (though I have seen multiple issues with tank corrosion due to incorrect tank material specification). Matt > Nathan, > > We've done a couple of systems with large unpressurized tanks (STSS). > They work well but there are a couple of things you need to pay attention > to. We use tap water to fill the tank which works fine but you have to > make sure the PH of the water is in the correct range. I can't remember > what that is off hand but the STSS manual has a whole section on correct > PH and want to add (I think it's baking soda) to correct the PH. The > second tip is make sure all the ports and the lid are properly sealed with > calk. The STSS tanks come with the calk, I'm not sure if other brands > include it. If you don't seal all the openings well when the tank heats > up and produces condensation that water will leak out the ports and create > a mess and reduce the efficiency of the insulation. > > We used to make our own heat exchangers with K soft copper and trex to > hold it all together. That worked well on most systems but we had one > where the copper eroded where it was in contact with the trex. We think > it was due to improper PH of the water in the tank. I'd recommend buying > the heat exchangers from the manufacture. > > Good luck, > Will > > __________________________________________________________________________________________ > Will White > Regional Field Operations Manager - New England > > Real Goods Solar > 64 Main St. > Montpelier, VT 05602 > Tel: (802) 223-7804 > Cell: (802) 234-3167 > www.realgoodssolar.com<http://www.realgoodssolar.com/> > > [Description: > RGS12_Q2_MYTH_static_signature_1b]<http://realgoodssolar.com/landing/87_solar_myths.php> > > > > From: [email protected] > [mailto:[email protected]] On Behalf Of Nathan > Stumpff > Sent: Friday, August 10, 2012 3:03 PM > To: [email protected] > Subject: [RE-wrenches] Thermal storage water stabilizer > > Thermal wrenches, > > I have a series of upcoming projects involving large (up to 10,000 gallon) > water storage. They are closed (air-tight) but unpressurized (oversized > expansion capability) systems, basically just a mass of water. We move > heat in (solar, masonry heater) and out (DHW, space heating) exclusively > via heat exchangers, so once we seal up the lid there is no introduction > of any new material, including air, until bladder replacement or other > maintenance, hopefully a long time off. > > Obviously de-ionized water would be the best choice for initial fill, but > it is not going to happen. My thought is that with no new source of > oxygen, minerals, etc., the small amounts that will be present on fill up > can't pose a big problem. > > Anyone with experience here? Any ideas or leads for a stabilizer to add on > initial fill? What problems am I not seeing? > > Many thanks, > -Nathan > > -- > Nathan J. Stumpff - Arctic Sun, LLC > NABCEP Certified PV Installer #091209-175 > NABCEP Certified Solar Heating Installer #032412-14 > [email protected]<mailto:[email protected]> > Office: 907/457-1297 > _______________________________________________ > List sponsored by Home Power magazine > > List Address: [email protected] > > Options & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out participant bios: > www.members.re-wrenches.org > > Matthew Partymiller Solar Energy Solutions LLC (859) 312-7456 [email protected] _______________________________________________ List sponsored by Home Power magazine List Address: [email protected] Options & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
