Research On Operational Characteristics And Commissioning Method For Energy Efficiency Of VAV System

15%to30%of the total energy consumption of large-scaled commercial buildingswith central air-conditioning systems is used on terminal fans of air systems. VAVsystems are widely used in office buildings. However, previous studies of VAV systemsmostly focus on control strategies and use simulation or experimentation as researchmethods, while the characteristics of VAV systems in real buildings have not beensystematically researched.Objective of this article is attempt to explain the large flow and small temperaturedifferencephenomenon in VAV systemsand to improve the difficulty in distributioncoefficient that the excessive reliance on temperature difference and issues in evaluationvarious scale of pipeline network.This article analyses the real characteristics of VAVsystems in buildings from the aspect of energy consumption, based on real buildingoperation data. Firstly, characteristics of VAV systems are decoupled into air flow andpressure head according to formula of air system energy consumption. Secondly, theopinion that “width of load distribution decides air volume and pipe network formdecides power consumption per unit air volume” is raised,“load dispersion ratio” and“energy consumption factor per unit air volume” are put forward as indicators instead of“air temperature difference” and “air transfer factor”, and a new methods of VAVsystem diagnosis are proposed in this article for the firist time. Finally, some casestudies using the methods are presented in this article. Thus, the coinstantaneousload ofseveral rooms belongs to one system differs from each other, andthis difference changesthe operational characteristics of the system which can not be ignored. Meanwhile, thescale of the pipeline network results in different transmission energy consumption,which should be evaluated in design.The method of dealing with air system data in this article is discussed inthe last part. Since air system has mass data which is difficult tobe utilized, airsystem data management is a necessary tool to air system research. DataWarehouse is used to manage air system data in this article.