Heating films for domestic heating are available to be powered directly from the mains electricity supply in different countries, e.g. 120 volts AC, 220 volts AC, etc. or low voltage, e.g. 24 volts. In general, due to safety issues, heating films supplied directly from the mains are only installed underfloor or in ceilings. Due to potentially hazardous voltages from mains electricity, protection from is usually required, either due to damage (e.g. nails) or water ingress. Most commonly, a.