I have a 6 gallon hot water tank. It has the heat exchanger circuit using the engine coolant to heat the water in the tank.
Considering making a solar water heater to replace the engine as the source of the water heating. A coil of copper tubing inside a "greenhouse" box in the sun. The tubing heats the water in the sun and circulates thru the heat exchanger, heating the water in the tank.
The water in a solar collector of about 2' square can get very hot very quickly in full sun. My questions are about circulation and water pressure. I'm guessing the system would have about 1 to 2 gallons of water that needs to be circulated. A small 12 volt pump can do that. The bigger question is how much expansion will the water do when heated? I'm sure I will need a pressure relief valve which if at the top of the circuit can also be the fill point when removed. Any thermal expansion experts here? The 6 gallons of water will absorb a certain amount of the heat, lessening the thermal expansion. But the specifics are all guesswork at this point. I'd like to minimize the level of guessing.
Considering making a solar water heater to replace the engine as the source of the water heating. A coil of copper tubing inside a "greenhouse" box in the sun. The tubing heats the water in the sun and circulates thru the heat exchanger, heating the water in the tank.
The water in a solar collector of about 2' square can get very hot very quickly in full sun. My questions are about circulation and water pressure. I'm guessing the system would have about 1 to 2 gallons of water that needs to be circulated. A small 12 volt pump can do that. The bigger question is how much expansion will the water do when heated? I'm sure I will need a pressure relief valve which if at the top of the circuit can also be the fill point when removed. Any thermal expansion experts here? The 6 gallons of water will absorb a certain amount of the heat, lessening the thermal expansion. But the specifics are all guesswork at this point. I'd like to minimize the level of guessing.