Within the energy auditing industry, particularly projects focused on compressed air systems, it is common for amperage measurements to be used as the basis for system evaluation and developing recommendations. Installation of true power meters is typically more time consuming and, due to equipment and personnel costs, more costly. A more ubiquitous approach utilizes current transformers paired with data loggers to strictly measure amperage from a single phase as a proxy for true power demand.
The purpose of this study is to review the significance of assuming static power factor values on energy savings estimates. True power measurements are used to evaluate system energy usage and the results are compared with estimates produced using the amperage proxy approach.
The findings show that a small percentage change in the power factor estimate can have a much larger relative impact on energy savings estimates. The magnitude of savings affected is found to be dependent not only on the power factor estimate but also on the observed loading of the unit. Parametric curves displaying percent full load amperage versus power factor are generated for various motor sizes and it is concluded that use of a correlation of power factor and load is an effective way of improving the amperage proxy approach.
Nathan Eason, P.E., C.E.M., C.M.V.P.
Nathan Eason is currently a Project Engineer with Lockheed Martin for the Tennessee Valley Authority (TVA) EnergyRight® Solutions Business + Industry incentive program. He is a graduate of the University of Memphis, with B.S. degrees in Mechanical Engineering and Earth Sciences. Having a strong foundation in fluid and thermal sciences, he participated in energy audits conducted with the local Industrial Assessment Center and received training in geothermal energy development and applications at the inaugural National Geothermal Academy. He is a member of American Society of Mechanical Engineers and Association of Energy Engineers, and is a registered Professional Engineer, Certified Energy Manager, and Certified Measurement and Verification Professional.
Victor M. Alas Jr., C.E.M., C.M.V.P., M.S.M.E.
Victor M. Alas is currently a Project Engineer with Lockheed Martin for the Tennessee Valley Authority (TVA) EnergyRight® Solutions Business + Industry incentive program. Victor has completed the review of projects covering a variety of energy savings and new load measures and technologies throughout the Tennessee Valley. While completing his Masters and Bachelors of Science degrees in Mechanical Engineering from The University of Alabama, Victor began his work in energy efficiency at the Alabama Industrial Assessment Center (AIAC) including a year as the Center Coordinator working under Dr. Keith Woodbury. Through AEE (Association of Energy Engineers), he has earned his CEM and CMVP certifications. He looks forward to continuing his professional development while helping the Nashville, TN chapter grow in strength and number. He served as Chapter President in 2018 . Victor is married to Stephanie, a nurse and they reside in Nashville. They have a daughter named Harrison June.