Defrost Kits are electric heating elements made of a set of thin metallic heating rods that are fitted into the suitable slots, under the coil of the thermo-fan. This layout simplifies the installation and guarantees homogenous dispersion of heat over the entire coil for even defrosting. The Defrost Kit melts the iced condensate, which accumulates on the airways when the fan is used for room cooling with Glycol-water set below the freezing point. Periodical defrosting enables the use of the thermo-fan for setting up cold-rooms, which are kept at low temperatures. The melted condense water drips to the fan's collection tray for drainage.

When using a Defrost Kit, it is required to use the FermFlex-Defrost controller, which controls both the fan-valve for cooling and the heating element for defrosting.