Energy Audit of Building Cooling System

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In terms of energy audit for building cooling system, following parameters are required to evaluate the operating system efficiency of the centralized chilled water system.

• Chiller water supply main header temperature
• Chiller water return main header temperature
• Chilled water flow rate at chilled water return main header
• Condenser water supply main header temperature
• Condenser water return main header temperature
• Condenser water flow rate at condenser water return main header
• Power input to chiller(s)
• Power input to chilled water pump(s)
• Power input to condenser water pump(s)
• Power input to cooling tower(s)

To measure theses parameters accurate measuring instruments are supposed to be utilized. The data logging interval is recommended to be 1 minute and the measurement duration should be at least 1 week. Table below summarizes the instrumentation in energy audit.

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It should be noted the measurement uncertainty should be within the prescriptive range and all instrumentation should be well calibrated. Additionally, the heat balance substantiating test should be used to verify the accuracy of the prescribed tolerance and it shall be computed over the entire normal operating hours with more than 80% of the computed heat balance within 5% over a one week period.

It should be noted the measurement uncertainty should be within the prescriptive range and all instrumentation should be well calibrated. Additionally, the heat balance substantiating test should be used to verify the accuracy of the prescribed tolerance and it shall be computed over the entire normal operating hours with more than 80% of the computed heat balance within 5% over a one week period.