Research On The Practical Evaluation System Of Hvac System By Commissioning

HVAC systems are necessary in people's life those consume large part of the whole social energy consumption. Decreasing energy consumption of HVAC systems is the urgent project and important task to the specialists even to the whole society. The extra and unnecessary energy consumption within the considerable HVAC energy consumption is caused by unreasonable design and improper operation, maintenance and management. To reduce the unnecessary energy consumption, the performance verification of HVAC systems should be taken in each stage, this kind of work is often called the HVAC system commissioning. But the so called HVAC system commissioning is too tough to carry out in practice, because it covers so many aspects of the question, involves so many interacting factors, real commissioning is complex or unworkable that makes it still stay in concept stage. A practical commissioning method that is not only workable but also covers the main problems is not available. This is the main reason that the commissioning work is commonly approval and hignly praised but not widely has its applications. Facing this fact, basing on the general idea of HVAC commissioning, suming up the foreign mature theories and experiences, associating the actual situation of our country, covering the main problems, a general commissioning method and practical evaluation system for HVAC system is proposed in this paper.The concept of deviation of systematic index based on the idea of the HVAC system commissioning theory is proposed in this paper. Associating with the actual situation of HVAC systems, main systematic elements are focused and elements have less importance are ignored, an objective and practical HVAC commissioning evaluation system has been established which can be used as a powerful means for HVAC system commissioning. With this method, energy consumption characteristics, user satisfactory characteristics and the cost characteristics of HVAC systems can be qualitatively and quantitatively analyzed and evaluated, so the real situation of the system design and operation can be objectively presented by the indexes of systematic deviation. The systematic characteristics of the real HVAC can be evaluated and graded, which can be relied on to perform diagnosises and improvements for further HVAC system commissioning.The establishment and application of our evaluation system is based on the Energy-plus simulation software, in which a building and its HVAC system model are set. By the characteristic analysis of the model building and model system including ideal arrangement of the equipment capaity and optimal setting of the opertional parameters, reference values of the indexes of systematic characteristics and the deviation of systematic indexes can be obtained. The general process and procedure of our method and evaluation system is introduced in details by two real case applications, one is for HVAC design commissioning and the other is for HVAC operation commissioning. After the two real case applications, the feseability, reliability and operability of our method and the evaluation system have also been verified.