These reverse the evaporator and condenser sides for the defrost cycle. Other types of ice sensor probes include plastic, steel, refrigerator defrost, and wind turbines. Alternatively, some systems use the hot gas in the condenser to defrost the evaporator. The condenser/evaporator (outdoor) fan will not run during defrost mode. The manufacturers then have the option to freeze, defrost or vacuum package it. Other early types of refrigerators also use hot gas defrost instead of electric heaters. In cheaper and/or older models, a defrost cycle is controlled via a mechanical timer. They were left neatly in refrigerators which did not defrost. Frozen plasma can take 40 or more minutes to defrost and deliver. For the frozen one, defrost them before cutting and trimming. These will turn off the machine and allow the ice-covered coils to warm and defrost. Heat pumps therefore have a provision for occasional defrost of the outdoor coil. The convertibles receive a glass rear window, allowing rear window defrost as an option. The indoor fan continues to run during the defrost cycle. The most frequent question asked is how long a turkey takes to defrost.