Hydronic system design in HVAC systems has recently experienced a few innovative techniques, generally oriented toward overall operating economy. Since the basic purpose of any HVAC system is thermal transfer and/or ventilation for comfort and safety purposes, neither the water side nor the air side can be considered an end in itself.

Recently, pumping systems have been designed in a manner that reduces water-flow requirements and refrigeration costs, while maintaining adequate space conditioning. Some changes include variable volume pumping, higher temperature differentials, resetting of termperature and pressure set points, and thermal storage utilization. These and many other energy saving techniques all have major impacts on the pumping system and equipment selection.