In-situ performance testing of fans and pumps for energy analysis

The effectiveness of energy-efficiency improvements to building mechanical systems is difficult to quantify; the improvements often require in-situ measurement of the mechanical equipment performance. This paper describes the development and evaluation of in-situ testing guidelines for fans and pumps developed under ASHRAE research project RP-827. The in-situ testing methods are designed to evaluate annual energy consumption and to account for part-load operations that are affected by overall system controls. A relationship between power consumption and load is developed for the equipment and system using a combination of direct measurements, statistical regression analysis, manufacturers` data, and engineering principles. Annual energy consumption characteristics are derived by combining test results with a user-specified distribution of loads. A comprehensive uncertainty analysis has been developed to estimate the overall prediction uncertainty of using in-situ testing results to evaluate annual energy consumption. The results indicate that reliable estimates of energy use can be obtained for fans and pumps with relatively few in-situ measurements.