Yesterday I did an inspection where I found CPVC in a crawlspace. It’s in Kansas where it gets well below freezing in the winter. As to what temperature the crawlspace actually gets, I don’t know.
Question 1: Is CPVC appropriate in unconditioned spaces where there’s a good possibility of freezing temperatures?
In this particular installation though, it appears the plumber wrapped it with heat tape which would take care of the freezing issue. There’s a plug coming out of the heat tape and then an extension cord coming down into the crawlspace from above, but the two were not connected.
Question 2: Do you leave heat tape plugged in year-round or only during the winter?
To be properly installed (in addition to the items already mentioned above) heat tracing should be thermostatically controlled and the pipe /tracing should be insulated. Otherwise, it still might not save a freeze during exceptionally cold / windy weather.