The main purpose of ventilation system is to meet the requirements of thermal comfort and air quality for the occupants. HVAC designers select air supply devices by using manufacturers’ data, under the assumption that the outflow from the elements is uniform and radially symmetric. Uniformity and symmetry hold only if air velocity vectors have uniform intensities and directions that are perpendicular to the diffuser inlet cross section. Unfortunately, these conditions are hardly met in the engineering practice. The most common case of diffuser installation is the flush ceiling installation, accompanied with the plenum box with side entry above the ceiling. Therefore, in the present article investigated is the influence of different geometries of the equalizing elements in the plenum box with the side entry connection on the symmetry of the jet and the flow distribution through the four-sided square ceiling diffuser. New designs of the plenum box with an inclined non-uniformly perforated plate and with an equalizing element with air guidance blades are proposed and evaluated numerically and experimentally. A better uniformity of the air discharge from the diffuser outlet to the ventilated room is achieved.

通风系统的主要目的是满足居住者对热舒适性和空气质量的要求。暖通空调设计人员在假定元件的流出是均匀且径向对称的前提下，使用制造商的数据选择供气设备。仅当空气速度矢量具有与扩散器入口横截面垂直的均匀强度和方向时，才会保持均匀性和对称性。不幸的是，在工程实践中很难满足这些条件。扩散器安装的最常见情况是齐平的天花板安装，并带有在天花板上方有侧面入口的通风箱。因此，在本文中，研究的是带有侧面入口连接的增压室中均衡元件的不同几何形状对射流的对称性以及通过四边形方形天花板扩散器的流量分布的影响。提出了具有倾斜的不均匀穿孔板和带有带导流叶片的平衡元件的增压室的新设计，并进行了数值和实验评估。从扩散器出口到通风室的空气排放更好地均匀。