Discussion of Design Method and Optimization on Airflow Distribution in a Large-Space Building with Stratified Air-Conditioning System

Indoor air distribution is a major concern in designing indoor thermal environment of a large space, which is different from normal buildings. Today, stratified air conditioning is a common choice for large-space buildings. Indoor air distribution with the stratified air conditioning is affected by many design parameters. These parameters have direct effects on thermal comfort, environment noise and energy consumption. Selection of these parameters thus becomes the key problem in design of indoor thermal environment in a large space. In this paper: a large-space building is taken as the study object. It was found that the cooling load varies linearly with the stratified height. The calculations of the air distributions were performed under the conditions of different stratified height, diameter and quantity of the blast nozzles. Based on calculated results, the alignment charts were plotted in an effort to determine the design parameters such as the height, the diameter and the number of blast nozzles and their selection range for a large-space building. According to the charts, the relationship of design parameters and their optimized selection are analyzed. It is clear that the lower the height, the less the energy consumption demand is, however; the noise level would be higher Based on above results, an optimized and practical methodology is formulated for the design of the air distribution in a large space.