It is copper oxidation.
It can maintain the cooling temperature of water and 80% of copper is available.
copper?
"How much" as a question is quite vague. Some hot water heaters are comprised of copper only. So this now depends on the size of the hot water heater. Some hot water heaters have no copper whatsoever.
The copper wire used in the solar water heater is wrapped in the shape of the coil to increase its surface area.
I don't know about the outside diameter of the hoses but, the outside diameter of the heater core inlet and outlet tubes are 3/4" (inlet) and 5/8" (outlet).
Yes, a hotwater heater may be placed outside anywhere in the state of Florida. It should be under cover such as a garage or shed.
Check for any blockage or buildup in the hoses to and from the heater core itself. Also check to make sure the thermostat is working properly. A cooling system flush may also be needed.
Check both the supply and return heater hoses from engine to heater for blockage or clogging: remove them and flush. Also check the inlet and outlet pipes on the engine and heater core for gunk buildup and leakage.
it's on the outside on the passenger side.near the heater core hoses.
Start out by checking for a vacuum leak both inside and outside for the a/c and heater.........
Because it is a very good transmitter of heat.
Copper, check your tablets or algaecides or maybe you have a heater.