Influence of air conditioners utilization on urban thermal environment

The urban heat island effect is essentially a kind of thermal pollution caused by artificial activity. Air conditioning units used in buildings release a great deal of heat into outdoors while they improve the indoor thermal environment. Therefore, it will cause a rise in the outdoor air temperature and worsen the urban thermal environment. A box model is presented in this paper; it is used to quantitatively determine the rise in outdoor air temperature caused by using domestic air conditioners in Wuhan. The results demonstrate the rise degree is 2.56 degrees C under inversion conditions and 0.2 degrees C under normal conditions, which indicates that thermal pollution is serious at stable atmosphere. To a certain extent, the rise of atmospheric temperature can be verified by the rise of lowest atmospheric temperature in Wuhan over recent years. (C) 2008 Elsevier Ltd. All rights reserved.