CPVC is used for hot water transfer in homes and business. Solar rooftop projects require heated water or heat exchange liquid to sometimes travel a long distance through piping exposed to cool or very cold temperatures. A lot of solar thermal heat can be lost from collector to water heater tank , radiator, or radiant floor heaters. This works under water and in subterranean installation prevent wet ground from leaching heat. Also prevents freeze overs for up to 10 hours in -10c with no circulation.