Solar "Batch" Hot Water Heater, Help Please
I would appreciate a little input on constructing a solar "batch" water heater system.
It will be a typical type setup whereas a 50gallon black water tank will be encased within a box with glass panel(probably glass door). I live in south Alabama, btw. The batch tank will simply be used to pre-heat water going into my indoor Hot Water Heater. SEE SKETCH.
1) How hot can these batch tanks get and what do you do to protect against excessive heat/pressure buildup? I thought to install some sort of automotive type thermostat that could vent the box as it gets too hot?
2) Somewhat in regards to question one, should a tempering valve be installed on the batch water tank to protect against excessive hot water going through the lines and into our indoor Hot Water Heater? I read where someone damaged their cpvc piping because of too much heat so assume 3/4 Pex piping would be best?
3) If I use standard pipe insulation for the underground line (one) and enclose that in solid corrugated pipe (lowe's) how much heat loss can I expect? My hot line, which will run from the batch tank to the indoor HW heater, will be about 50ft in length and approxiametly 18 inches underground(top soil).
4) Should I connect the "hot" water line, coming from batch tank to HW heater, at the bottom drain valve or from top of HW heater via "cold" water in? I plan on supplying tap water to the batch tank from our cold line at master bath faucette? Can I turn off the valve at the cold water "in" to the HW heater itself as such? Maybe turn back on when I want to bypass the batch tank?
5) Can I also run a hot line between my master bath faucette and the batch tank? This would allow me to possibly circulate the hot water in having instant hot water to each faucette. However, how will this affect the flow of everything? I mean what happens when the batch tank is cold? Can I just tie in at a lower point then HW heater line?
6) Lastly, how do I protect the batch tank in freezing weather or from getting too cool? I know insulating lines within the box wil be required but how to keep temperature within the box itself up? Would building a housing somewhat partially below grade help?
Last edited by Ralph III; 10-28-2011 at 04:50 PM.