I am installing a humidifier in my house, and I need to tap into the water line. My builder used PEX plumbing and, of course, I don't have any of the crimping tools necessary for working on PEX. But, there is a length 3/4" copper pipe that goes between my water heater intake and the main PEX water line above. The total length of this copper is only about 2 or 3 feet. I would like to solder in a tap for the humidfier connection into this copper section, but I am concerned about the PEX that this pipe is connected to. Does anyone know how far I have to be away from the PEX connection before I can safely sweat a fitting into the copper pipe? If I just wrap a wet towel near the PEX connection (between the crimp and the joint to be soldered), will this be an adequate heat sink to avoid damage to it?
Thanks in advance for any advice.