Glass Doors

Economy of glass doors on refrigerated display cabinets.

Glass doors on Refrigerated Display Cabinets in a supermarket.

The idea of fitting glass doors on vertical refrigerated display cabinets seems logical from the point of view of energy saving. The “old” argument that doors form a barrier that reduce sales, is simply unsubstantiated. Still, there are some catches…….

Glass doors on display cabinets for frozen food

Glass doors for upright (vertical) freezers are often fitted with anti-sweat heaters, to maintain good visibility. But to have a heater inside a freezer is clearly not energy efficient. A vertical freezer with glass doors uses two times as much energy as an open island type (“tub”) freezer without covers (per area of display surface). Most efficient is an island type freezer with sliding glass covers.   

Island type freezer with sliding glass covers, in a test room conforming to EN ISO standards.

Glass doors on vertical chilled cabinets (“multidecks”)

Glass doors on vertical chilled RDC’s are generally a good idea, as they can reduce the heat load into the cabinet by some 50%. However, when you have a very energy efficient cabinet to start with, the cost savings may not cover the investment within a 5-year period. Apart from the investment, there are additional labour costs for filling and cleaning – these are generally not taken into account.


In the Netherlands, we had a heated discussion on the obligation to fit chilled vertical cabinets with glass doors. The discussion ended in the high courts. As a result, many detailed reports appeared on the subject. But regrettably, these reports are all in Dutch. Nevertheless, the expertise is alive and available for you at Saint Trofee.