Aerodynamic Isolation of Open Refrigerated Vertical Display Cases using Air Curtains

This chapter presents an experimental study on the effects of some of the most important variables that affect the infiltration rate in open refrigerated vertical display cases at steady operation. The variables were defined in dimensionless forms and were categorized in two groups. The goal was to examine the cross-effects of the first group (primary variables) by performing tests on the permutation of the variables, and to obtain some correction functions that contain the effects of the (secondary) variables thought to have smaller impact on infiltration. Tracer gas method, a new means to measure infiltration rate, is described and compared with other conventional methods. Most variables showed noticeable impacts on infiltration either linearly or non-linearly, some of whom did not show very well-defined patterns with infiltration, which indicates there are significant cross-effects among the variables. Others such as temperature difference and relative humidity showed no or negligible effects on infiltration.