I've recently installed a Paloma PH-28 tankless water heater on the outside wall of my home in Atlanta. the heater has its own internal heater to keep it freeze proof.
But I need to insulate the supply lines as we will have several hard freezes each winter.
I will buils a box (about 14X24X10 to surround the pipes. Is typical foam pipe insulation going to protect these 3/4 copper supply lines or will I need more insulation?
I'm thinking of simply stuffing the box with fiberglass insulation, but I wounder what will happen if it gets wet.
I've also considered slicing a 4" pvc pipe in hals putting it around the supply pipes and filling it with foam insulation.
And/or - I have a thermostat that will power up at 38 degrees and power down at 50 degrees. I've thought about just putting a 100 watt lightbulb in there.
Heat tape won't work because I only have about 30 inches total of pipe that is exposed and the tapes say "do not install on pipes less than tape length"
Any suggestions, experiences are welcome.