Application is solar hot water. CPVC pipe melts at 170 degrees F but there is 30-feet of copper before it transitions to the plastic CPVC. Outside ambient temperature is 60 to 85 degrees F. What is the optimum temperature to set at the discharge side of the solar hot water storage tank so that it will enter the CPVC below 170F?
It seems to me the optimum would be to insulate the copper pipe and adjust the flow rate to keep the temperature to less that 170F, I don't see the point in collecting the energy then throwing it away. Rereading the question, I see you say tank, not collector, what is the end use of the water? can you mix some cooler water with it? that way, instead of throwing away heat, you have a larger volume of the 170F water.
