thomas rubino wrote:Yes, even with a relief valve it is still a closed system.
You do not want to be nearby if a hot water pressure relief opens up.
Steam/hot water is a dangerous thing , not to be taken lightly.
So your in Baja, wanting extra hot water.
Rather than copper pipe what about black poly pipe? Is it available ?
With all your sun I would think a simple sheet of plywood with black pipe looped back and forth would make a fine water heater.
Storing that water in a raised black painted tank would give adequate pressure for showers and washing.
A different option if you have wood available would be a stand alone rocket stove water heater.
Free build your own plans are available if you had interest in that.
thomas rubino wrote:Hi Celeste; Welcome to Permies!
I would say your drawings are accurate as far as heating water expands and would flow into a second tank.
We need way more information about how you are attempting to construct your water heater.
What your needs are from that water and what style of system. A closed loop (can be dangerous) or an open tank (very safe)
Solar hot water does work. I have never built any myself but have seen systems here in the N.W. that worked all winter if the sun shined.