Life Cycle Cost Comparison Between Motors Equipped with Variable Speed Drives and Dampers for Pumps and Fans

Motor efficiency is important, but it is a small contributor to overall system efficiency. This paper will not review motor efficiency as a single important factor for energy saving, but the efficiency of the whole system. Meaning, the converted electrical energy into useful mechanical work for pumps and fans. This paper presents a review of relevant literature on life cycle cost (LCC) comparison between two different methods of motor flow control used for pump or fan systems. This study aims to provide an LCC mathematical model for new or existing pump or fan systems projects. The purpose of this study is to determine operating cost of the motor running at constant speed with dampers and compare them to variable speed drives (VSD) when utilised for the same application. The comparison will be carried under the same load demand and same cost of energy. The review will present an LCC mathematical model that will provide substantial financial guidance for pump or fan system projects.