A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Engineering and Technology

Thesis (M.Eng.) - Asian Institute of Technology, 1990

A feasibility study on ice storage in an office building in Bangkok, which has 24 floors in one block and 2 floors in another block, is described in this thesis. The ice storage under a partial and modified demand-limited design with constant proportion control are considered. It has been found from a preliminary results of an energy audit that the air conditioning system consumed about 61.1% of total building electrical energy consumption and chillers consumed about 51.8% of total electrical energy consumption in air-conditioning (A/C) system. The average coefficient of performance of the chillers is 4.77 at the daytime (450 ton chiller) and 3.45 at the nighttime (50 ton chiller) . The average system efficiency is 1.55 kW/ton. The DOE- 2. lC building energy analysis computer program was used to analyze the energy consumption in the studied building. Conventional heating ventilation air-conditioning (HVAC) system was compared to ice storage systems using simple payback periods, net present value and internal rate of return. It was found that at present electricity rate structure , partial storage is more economically feasible than other operating modes . But under a number of alternative time-of-day (TOD) rate structure, the modified demand-limited storage system present a better economic feasibility, especially when the energy charge for the off-peak period is differentiated from other period.