Thermal Comfort and Environmental Modelling in Atrium Buildings

Atrium spaces are extensively used in modern architecture and are often claimed to offer some passive benefits to the internal environment as well as energy efficiency opportunities. It has also been established over recent years that it is difficult to predict and analyse the internal environments of atria because of the complex nature of their operation and air flows. The thermal sensation experienced by occupants in a building space is known to be affected by four environmental factors - air temperature, air velocity, humidity and mean radiant temperature (MRT). The calculation of the comfort level in atrium spaces involves two difficulties compared to other spaces. Firstly, solar radiation that can penetrate the atrium skylight has a significant impact influencing thermal comfort and adds to the difficulty of calculating MRT; and secondly, there is strong temperature stratification in the space due to stack effect, which makes it difficult to obtain the air temperature. This paper, which is part of an ongoing project of a systematic study on the thermal environment of atrium spaces, focuses on the above two issues and presents a tool developed for the evaluation of the comfort level in atrium spaces. For the first issue, CFD analysis is performed and a new MRT calculation method which can take solar radiation into account is used. A platform is then built for the data from the two analyses to communicate and exchange. An application of the tool is presented finally.