Theory And Method Of On-site Operating Energy Efficiency Surveying Of Heating Ventilation And Air Conditioning System

Due to lack of energy storage, in the known first energy, like coil, oil and gas, personal occupancy of our country only take one ninth to one fourth of world average level. Energy challenge of China becomes to be even more austerity, and contradict of energy supply and efficiency of end usage becomes apparent. Under long living thought of"manufacture first, then life", our country still inclines to industry energy saving, ignoring building energy efficiency. And the proportion of personal energy occupancy will increase because of the development of service vocation. Thereby, how to use limited energy to fulfill the development of economy and society and to reach the requirement of enhancing of living level gradually becomes an important problem. Also, it is the gravest challenge we have to face. Full-scale energy saving may become the only way to solve contradict between energy supply and need. And building energy saving may be a potential method, the most efficient way in all energy saving. Considering the big proportion of Heating, Ventilation and Air Conditioning system in building energy consumption, HVAC system energy saving may seem to be a useful way to implement building energy efficiency. Exact and available investing method and theory is the base of HVAC energy efficiency, no matter operating, retrofit and design. All HVAC relating work is based on exact data of HVAC system operating. But, till now, no specific standard is published to explain HVAC investing work, so, it is meaningful to establish concrete clause of HVAC on-site investing work.This paper explains the HVAC system operating efficiency theory and method from four factors:1. Influencing factors of HVAC system;2. Main instruments and its requirement;3. Indoor and outdoor environment and cooling or heating unit parameters on-site investing;4. Transporting system, including water system and air system."HVAC system energy efficiency"means the ration of HVAC system load and energy consumption. Ever individual HVAC system could be divided into three subsystems: cooling/heating unit, including cooling or heating unit and cooling water system; water system, specifically cold water; air system, end units and air handling unit. Through analyzing, we conclude the influencing factors as following: 1. The power consumption of ever subsystem directly influences system energy efficiency;2. Unit COP is the foundation. The higher of COP, the higher potent of DEER to reach;3. If the designing cooling load is stable, the higher of ever subsystem importing power, the greater influence it may has;4. Under the matching of cooling/heating unit and cooling transporting system, cooling unit energy consumption will define the value of DEER under the COP value;5. The change of cooling requirement will directly influence the cooling load, Q;6. The set of pipe system will directly define the operating policy, influencing ever subsystem energy consumption;7. The range of the change of Cooling load and ever subsystem will influence the EER.Different investing progresses are established to fulfill the diversity of different HVAC system after the influencing factors are found. But, totally, the basic parameters would not change; generally, they would be the supplying cooling load Q and consumption N. And these instruments exists commonness, like temperature, relative humidity, velocity, pressure, flux, and electric current and volt. The requirements and methods are different considering different HVAC system and on-site conditions. In all important parameters, the cooling/heating system is the most important of all.