Probabilistic assessment of overcooling risk for a novel extra-low temperature dedicated outdoor air system for Hong Kong office buildings

The main purpose of this research is to analyze and compare the energy performance of two different novel air conditioning systems; one is a dedicated outdoor air system (DOAS) with a parallel system and the other is a heat-pump-integrated liquid-desiccant and evaporative-cooling-assisted 100% outdoor air system (HPLD-IDECOAS). It was assumed that office buildings served by each system were located in six cities representing four different climatic regions in China. The hourly thermal loads of the office buildings meeting the local building design codes of each selected city were predicted by the TRNSYS 18 software package. The hourly thermal load data were imported into the commercial engineering equation solver (EES) program to estimate the operating energy consumption of each system via detailed energy simulations performed using valid system simulation models. The results show that the HPLD-IDECOAS has higher energy-saving potential than the DOAS with a parallel system in climate regions with high humidity, whereas, in dry regions, the difference in energy consumption between the two systems was not significant.

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A simplified model for evaluating the energy saving potential of adopting demand controlled ventilation in office buildings in Hong Kong

Indoor and Built Environment ◽

10.1177/1420326x16666620 ◽

2016 ◽

Vol 27 (1) ◽

pp. 47-58 ◽

Cited By ~ 4

Author(s):

Jie Jia ◽

Wai-Ling Lee ◽

Hua Chen ◽

Han Li

Keyword(s):

Hong Kong ◽

Energy Saving ◽

Office Buildings ◽

Simplified Model ◽

Design Parameters ◽

Subtropical Climate ◽

Original Design ◽

Energy Saving Potential ◽

Controlled Ventilation ◽

Demand Controlled Ventilation

Demand controlled ventilation (DCV) to conserve energy while maintaining an acceptable indoor environment has been used for over 30 years. However, little work has been done on evaluating its energy saving potential in cooling dominant office buildings in subtropical climate. In this study, the energy saving potential of DCV system for use in six representative office buildings in Hong Kong was investigated by simulations. Simulation validation was done based on in situ measurements and site surveys. The findings show that, based on their original design conditions, the use of DCV could lead to 12.5–26.1% energy saving. To facilitate quick estimation of the energy saving potential of DCV system, further simulations were performed for the development of a simplified model. The simplified model relates the energy saving potential to key air-conditioning system and design parameters. Based on the simplified model, sensitivity analysis was conducted to quantify the influences of different parameters on the energy saving potential of DCV system. The developed model method can be used for prediction on the energy saving potential in a wider application of DCV in Hong Kong.

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