With the home raised on piers and the lower level neither insulated nor conditioned we had to do something to keep the water line coming up from the slab and into the bottom of the home envelope from freezing. We decided to build a 2×4 framed enclosure from the slab up to the home envelope and had the insulation guys spray it with closed cell foam. Plumber then ran heat tape along the pipe and left us with a plug at a nearby outlet so we could plug it in when/as required. You can get a thermostatically controlled outlet to make this approach a little more elegant.
This approach still left me nervous, so I looked for a way to heat the enclosure, and it was surprisingly hard to find a suitable heater with a thermostat that would do the job. Finally found a German-made heater made by Stego, 950 watts, with a built in thermostat. I ordered it from Galco and I think it took a couple of months to arrive. The thermostat can be set at 32 degF or above.
