The invention concerns a refrigeration system (12) including an evaporator (20) for evaporating a refrigerant and an air displacement arrangement (36) for causing air to be displaced across the evaporator. The system also include a control system (44) for adjusting the volume of air and/or the direction at which air is caused to be moved across the evaporator by the air displacement arrangement. The volume of air and/or the direction at which air is caused to be moved across the evaporator is controlled by the control system in response to measurements taken by a gauge such as a thermometer (46) for measuring the air off temperature of the evaporator and a timer (48). The air displacement arrangement is typically in the form of a fan having pitch-adjustable fan blades. This allows the pitch angle of the fan blades to be adjusted in order to change the air volume and/or the direction of air flow.
