A plurality of resistance heater rods are assembled in parallel relationship between the plurality of normally extending brackets and their associated retainers to comprise a subassembly which is then attached as a unit to an evaporator coil. Each of the coils is a continuous element that forms a complete loop with the ends then overlapping such that they are generally centrally located but are located on either side of midpoint such that their movement is not interfered with by other existing structures.