ON SAVING PUMPING POWER IN HYDRONIC THERMAL DISTRIBUTION-SYSTEMS THROUGH THE USE OF DRAG-REDUCING ADDITIVES

A feasibility study has been conducted to determine whether surfactant drag-reducing additives might be used in hydronic heating and cooling systems for buildings in order to decrease the pumping power required to circulate the fluids. An analysis of the possible match between ad ditives and system characteristics was undertaken in this context. The question of the level of drag reduction and degradation in - and down stream of - discrete components such as fittings and valves was also i nvestigated, together with the question of possible heat transfer redu ction in heat exchangers. Preliminary experimental results indicate th at pumps, valves, and fittings will not introduce serious difficulties , and that the heat transfer reduction may be controlled. Estimates we re obtained to determine the potential energy and cost savings that co uld be achieved. Issues of maintenance, compatibility, and safety are also discussed, and some recommendations for the implementation of the additives are made. This analysis leads us to believe that the use of surfactant drag-reducing additives in hydronic systems could be imple mented at small cost, and would lead to savings in pumping power of th e order of 50%.