Numerical study on heat blocking efficiency of non-recirculating air curtain and its optimal discharge velocity

Shinshu University, Department of Architecture, 4-17-1 Wakasato Nagano, Japan

^* Corresponding author: shany@shinshu-u.ac.jp

Abstract

From the point of view to reduce energy consumption, door open while air conditioner running on buildings have a problem. To solve the problem, many facilities for entrance with vestibule, revolving door, and air curtain are utilized. Among the facilities, the air curtain cuts off the indoor and outdoor air by discharging the wide air surrounding the opening, thereby preventing the heat loss from the indoor. The purpose of this study is to evaluate the heat blocking efficiency of non-recirculating air curtain and to evaluate its optimal discharge velocity. To achieve this goal, the infiltration rate across the single-side opening were investigated with air temperature differences between areas by transient CFD simulation and the results were compared with the steady-state calculation method. In addition, to evaluate the heat blocking efficiency of non-recirculating air curtain, the calculation model was set up and several cases with discharge velocity were compared. The results show that the discharged air from the air curtain causes a deflection from the high temperature area to the low temperature area, and the deflection decreases with increasing the discharge air velocity. In this study, the safety factor for deflection modulus of the non-recirculating air curtain was calculated 2.75.