Implication of global warming on air-conditioned office buildings in Australia

With the accelerated trend of global warming, the thermal behavior of existing buildings, which were typically designed based on current weather data, may not be able to cope with the future climate. This paper quantifies, through computer simulations, the increased cooling loads imposed by potential global warming and probable indoor temperature increases due to possible undersized air-conditioning system. It is found from the sample office building examined that the existing buildings would generally be able to adapt to the increasing warmth of 2030 year Low and High scenarios projections and 2070 year Low scenario projection. However, for the 2070 year High scenario, the study indicates that the existing office buildings, in all capital cities except for Hobart, will suffer from overheating problems. When the annual average temperature increase exceeds 2°C, the risk of current office buildings subjected to overheating will be significantly increased. For existing buildings which are designed with current climate condition, it is shown that there is a nearly linear correlation between the increase of average external air temperature and the increase of building cooling load. For the new buildings, in which the possible global warming has been taken into account in the design, a 28-59% increase of cooling capacity under 2070 High scenario would be required to improve the building thermal comfort level to an acceptable standard.

Occupant health and productivity : an Australian perspective

The issue of whether improved building services such as air quality, provision of daylight, thermal comfort etc, have a positive impact on the health and productivity of building occupants is still an open question. There is significant anecdotal evidence supporting the notion that health and productivity of building occupants can be improved by improving the quality of the indoor environment, but there are actually few published quantitative studies to substantiate this contention. This paper reports on a comprehensive review of the worldwide literature which relates health of building occupants with the different aspects of the indoor environment which are believed to impact of these issues, with a particular focus on studies in Australia, The paper analyses the existing research and identifies the key deficiencies in our existing understanding of this problem. The key focus of this research is office and school buildings, but the scope of the literature surveyed includes all commercial buildings, including industrial buildings. There is a notable absence of detailed studies on this link in Australian buildings, although there are studies on thermal comfort, and a number of studies on indoor air quality in Australia, which do not make the connection to health and productivity. Many international studies have focused on improved lighting, and in particular the provision of daylight in buildings, but again there are few studies in Australia which focus in this area.

A Method of Preparing Future Hourly Weather Data for the Study of Global Warming Impact on the Built Environment

The dynamic interaction between building systems and external climate is extremely complex, involving a large number of difficult-to-predict variables. In order to study the impact of global warming on the built environment, the use of building simulation techniques together with forecast weather data are often necessary. Since all building simulation programs require hourly meteorological input data for their thermal comfort and energy evaluation, the provision of suitable weather data becomes critical. Based on a review of the existing weather data generation models, this paper presents an effective method to generate approximate future hourly weather data suitable for the study of the impact of global warming. Depending on the level of information available for the prediction of future weather condition, it is shown that either the method of retaining to current level, constant offset method or diurnal modelling method may be used to generate the future hourly variation of an individual weather parameter. An example of the application of this method to the different global warming scenarios in Australia is presented. Since there is no reliable projection of possible change in air humidity, solar radiation or wind characters, as a first approximation, these parameters have been assumed to remain at the current level. A sensitivity test of their impact on the building energy performance shows that there is generally a good linear relationship between building cooling load and the changes of weather variables of solar radiation, relative humidity or wind speed.