Efficiency of pump operation in hydronic heating and cooling systems

Abstract

Developments in pump technology provide new possibilities of improving both the efficiency and the quality of control of hydronic heating and cooling systems. Improved pump efficiency and direct flow control can substantially reduce the drive power to circulation pumps. Measurements show that a simple VSD (variable speed drive) does not unduly degrade the efficiency of commonly used pumps. An example from a residential heat pump installation indicates possible savings of around 30 % of the total drive energy to the heat pump. Another example illustrates how direct flow control can simplify systems and reduce electric drive power in supply-air conditioning systems.