| In the subtropics, air conditioning serves to maintain an appropriate indoor thermal environment not only in workplaces during daytime, but also at nighttime for sleeping in bedrooms in residences or guestrooms in hotels. However, current practices in air conditioning, as well as the thermal comfort theories on which these practices are based, are primarily concerned with situations in which people are awake in workplaces at daytime. Therefore, these may not be directly applicable to air conditioning for sleeping environments.; The thesis reports, first of all, on both a questionnaire survey of the current status of sleeping thermal environments and bedroom air conditioning, and a field monitoring of overnight indoor air temperature and relative humidity in a number of air conditioned bedrooms, in residential buildings in subtropical Hong Kong.; Secondly, a theoretical study on thermal comfort for sleeping environments is presented. A comfort equation applicable to sleeping thermal environments was derived by introducing appropriate modifications to Fanger's comfort equation.; Thirdly, a simulation study to investigate the characteristics of nighttime bedroom cooling load in the subtropics, using a building energy simulation program---EnergyPlus, is presented. The results of the simulation study showed that the characteristics of nighttime bedroom cooling load differed significantly from those at daytime.; Finally, the thesis reports on a study on the outdoor air ventilation rate in bedrooms where RACs are employed. Field measurements of both the indoor overnight carbon dioxide (CO2) levels and the outdoor air ventilation rates in bedrooms employing RACs, as well as laboratory experiments on the ventilation characteristics of RACs were carried out. The results of the study suggested that the outdoor ventilation rates in the studied bedrooms equipped with RACs could not meet the ventilation requirement specified in ASHRAE Standard 62-2001 even if there was only one occupant in a bedroom. (Abstract shortened by UMI.)... |
