The impact of retrofitting doors on performance of a retail display cabinet

Open fronted retail display cabinets for chilled food are prone to infiltration of warm and moist ambient air. This increases the heat loads on the cabinets, reducing energy efficiency and ability to maintain temperature control. Air curtains are employed to form a barrier to infiltration but are typically limited in their effectiveness. Adding doors can curtail a considerable proportion of the infiltration depending on door opening frequency. This paper describes ISO23953 test room measurement of the impact of retrofitting doors to a typical open fronted display cabinet. The open fronted cabinet was found to maintain test pack temperatures between 7.4 and -1.0°C (M2 classification with rounding applied) and consume 46.9 kWh/m2. Fitting doors to the same cabinet reduced the temperature span to between 3.6 and -1.0°C (M0 classification) and energy consumption to only 51.5% of that used by the open cabinet. Further adjustments were made to raise the maximum pack temperature to a value similar to the open cabinet and the resultant temperature span was between 7.2 and 3.4°C (M2 classification with rounding applied) and energy consumption only 39.4% of that used by the open cabinet.