Abstract: The icing of the evaporator for refrigerant in a refrigeration system is checked by an air-permeable web of wire mesh which is moved along an endless path extending in front of the inlet of the evaporator to collect moisture from the flow of atmospheric air which is conveyed into the evaporator. Successive increments of the web are thereupon regenerated by melting or mechanically removing the ice and frost and by thereupon drying and cooling the increments before they return into the portion of the endless path in front of the inlet of the evaporator. Cooling of the web can be effected in a discrete cooling device or by causing a portion of the path to extend behind the outlet of the evaporator so that the web is cooled by cool atmospheric air which leaves the evaporator.