The analysis and design of the variable chilled water systems for large air conditioning systems have been presented. Four variable chilled water systems are studied. They are the parallel pumping, series punmping, two-speed pumping and variable speed pumping arrangements. Comparison in the energy conservation among the four systems operating at the same five cooling load conditions, which are expected to represent the cooling loads of the hotel, showed the result of the largest and smallest energy conservation as follows: 1. Series punpming system 2. Parallel pumping system 3. variable speed punmping system 4. two-speed pumping system. The maximun conserved energy for each system is 41.8% 34.7% 33.9% and 29.6% respectively. However, in consideration of the simplicity in the design andn control of the systems, the parallel pumping system is highly recommended.
