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This paper presents a combined daylight, airflow network and building energy simulation of a Public Rental Housing (PRH) development in Hong Kong to fulfil the requirement of the local green building guidance. The numerical modelling results are partly validated by on-site measurements during the period with the highest monthly average outdoor temperature. Different ventilation control strategies are simulated to optimize natural ventilation performance. The simulation results show that the full-day ventilation strategy contributes to a lower average and peak indoor temperatures compared to the non-ventilation and night-ventilation scenarios. The indoor operative temperature of a worst-case vacant flat lies under the upper 80% acceptability limits in ASHRAE 55 during 67.5% of the modelled period in July. On the other side, at least 95.6% of the habitable area in the case buildings is predicted to experience a higher average daylight factor of 1% compared with the local green building guidance. Furthermore, the energy saving potential of the combined natural ventilation and daylight strategies is anticipated to be 51.9% for air-conditioning and 8.3% for lighting compared to a baseline building, respectively. [ABSTRACT FROM AUTHOR]

Abstract: In sub-tropical city of Hong Kong where summer is hot and humid, the usage of outdoor spaces is often hindered due to thermal discomfort. In order to improve the thermal comfort of the outdoor environment and to make urban outdoor spaces delightful places for people to use and enjoy, better understanding of the thermal perception of people is needed. This paper presents the results of an outdoor thermal comfort study conducted in Hong Kong. The findings of the study reveal that air temperature, wind speed and solar radiation intensity are influential factors in determining the thermal sensation of people outdoor. Based on our analysis, the neutral physiological equivalent temperature (PET) in summer in Hong Kong is around 28°C. Under shaded condition, a wind speed of 0.9–1.3m/s is needed for a person in light clothing to achieve neutral thermal sensation in an urban environment. This understanding can contribute towards establishing wind performance standards for thermal comfort in hot and humid tropical and sub-tropical cities. [Copyright &y& Elsevier]

Abstract: In Hong Kong, conventional air-conditioning (AC) systems cause a high energy consumption and poor indoor thermal comfort. This paper investigated the AC load profiles of three typical local commercial buildings, i.e. office, hotel and retail, and examined the energy consumption of liquid desiccant cooling system (LDCS) for these buildings. Simulation results showed that the cooling load contributed to more than 98% of total annual load, with high latent load proportion from March to September. The high reheating ratio, i.e. from 60% to 90%, is found to be the main reason for the poor thermal comfort. Therefore, the LDCS which could handle sensible and latent loads separately was proposed. However, the electricity-driven LDCS was found not suitable for local commercial buildings. significant energy saving could be achieved by the solar-assisted LDCS system with thermal storage, when the installation area for solar collectors is larger than the minimum required one, i.e. 9.7m2/(kWm−2) for office and 12.7m2/(kWm−2) for hotel buildings. Energy saving of different system types with different installation areas was also studied. The solar-assisted LDCS shows more energy saving in winter but less in summer. Results and conclusions can be useful for researchers and local engineers. [Copyright &y& Elsevier]