Effects of Cooling Tower Performance to Water Cooled Chiller Energy Use: a Case Study toward Energy Conservation of Office Building

This paper presents results of a study on effects of cooling tower performance to energy consumption of a water cooled chiller system of an office building in Jakarta the capital city of Indonesia. The building was recorded as a less efficient office building with energy use intensity reaching 271 kWh m-2, year-1. The study was conducted by running a water cooled chiller with alternately two different cooling towers of similar specified capacity. Energy and temperature performances of the cooling towers were tested and evaluated. Performance parameters of the chiller that rejected heat to each cooling tower were evaluated, and then the chiller performances involving its energy use were calculated. It was found that one cooling tower had less air flow rate. Its efficiency was only 38% which was much lower than the efficiency of another cooling tower of 61%. Performance of the chiller to be operated with lower efficiency cooling tower, decreased by 5.5% and power consumption increased by 4.1%. The result of this study also showed that cooling tower performance was an important parameter that could make an office building less-energy efficient.