The Optimal Design of the Air Distribution System for a Library Located in the Subtropical Area

Abstract

In this study, the critical operation parameters related to the heating, ventilation, and air conditioning (HVAC) system of a campus library are numerically optimized. The objective of this study is to improve the standards related to thermal comfort and indoor air quality (IAQ) of the campus library. As a result, the library's energy consumption is significantly reduced with this new HVAC system design. The computational fluid dynamics software ansys fluent and experimental measurement are used to verify the effects of changes in velocity, temperature, and relative humidity (RH) of the air supply system (three operating parameters) on the ventilation efficiency. The ventilation efficiency is also assessed by parameters such as AC power consumption, the predicted mean vote (PMV) for thermal comfort, and CO2 concentration for IAQ (three-target performances). A response surface was developed numerically using ansys designxplorer to analyze the relationship between those three operating parameters and the three mentioned target performance characteristics. The optimization results show that the target performance of CO2 concentration should be <1000 ppm; in addition, the PMV should be in the range of −0.5 < PMV < 0.5. The results show that if air supply velocity, temperature, and RH are set to 1.0 m/s, 23 °C, and 40%, respectively, then the library electricity consumption (and cost) can be significantly reduced by up to 22.3%.