a fixed threshold an alternative solution could consist on waiting for a fixed time before switching on the fan after the compressor is switched off warming phase this phase is characterised by having the compressor switched off and the fan switched on or off according to the humidity request and the evaporator temperature in particular the fan will be switched on if the appliance needs to be humidified and the evaporator temperature is warm enough in this way it is possible to create any of these four conditions cool down and humidify with the cooling distribution phase not achieved with the traditional refrigerators warm up and boost the humidification if in the warming phase the evaporator fan will be constantly kept on warm up without humidifying or with a reduced humidifying effect if the fan and the compressor are maintained off during the warming phase cool down and dehydrate by maintaining the fan on in the cooling storage phase in this case the cooling storage phase and the cooling distribution phase coincide the temperature controller reads the temperature sensor s inside the cavity such sensor could be placed for example on the evaporator and or inside the cell such temperature readings together with the user set temperature are converted into a cooling request level this conversion can be obtained by the use of standard control methods proportional integral pi proportional integral derivative pids hysteresis or more advanced techniques such as neural fuzzy or data fusion methods the humidity controller has the same function for the humidity control problems it converts the relative humidity level acquired by a dedicated sensor or inferred by temperature measures.