Effect of design parameters of unheated twin air jets on thermal conditions near the doorway

One way to prevent cold air from entering through the doorway into a building is to use an air curtain. It is a stream of air blown across the doorway that acts as a thermal barrier. This paper presents the effect of the main design parameters of unheated horizontal twin jets on thermal conditions by the doorway.For the experiment a full-scale air curtain system with a shelter tunnel was built in the doorway of a laboratory hall.The results show that by installing one-stage or two-stage twin jets in entrances inside the shelter tunnel, comfortable working conditions can be achieved near the doorway without heating the blowing air..