we thermo- tech industries (oem) are the manufacturer of superior quality thermo- flex brand electrical door heater for deep freezer door, normally inside temperature of deep freezer ranges from -20 0c to -40 0c. door heater are used to prevent the ice formation at the door gasket and possible damage to the door.
the door heaters are supplied with output of 22.5w per mtr. with circular cross section for -20 0c & 45w per mtr. with flat cross section for lower temperature of the cold room.
the door heater normally work at 230 volt but can be supply at any other volt and wattage output if desire.