Air curtains for infiltration control - a computational fluid dynamics analysis.

An investigation has been carried out using computational fluid dynamics methods to study the performance of an air curtain at the door of a heated building. A number of operating conditions have been studied and observations are made on the effectiveness of infiltration control and energy use. Comparisons are also made with previously published design data and results from an accepted infiltration analysis. It is shown that the calculation method generates plausible and very detailed results which conform well to physical interpretation. It was found that at too low a supply velocity the air curtain was deflected to outdoors and the energy supply was wasted. Similarly, too high a supply temperature also prevented the air curtain operating correctly. With the air curtain operating successfully the predicted heat transfer characteristics indicated an efficient use of energy and acceptable indoor temperatures, but with air speeds of up to 2.5 m/s at low level within the building.