ESTABLISHING AMBIENT DESIGN CONDITIONS AND WEATHER ENVELOPE FOR ISLAMABAD, LAHORE AND PESHAWAR

Abstract

This paper presents the statistical analysis of dry bulb temperature, wet bulb temperature and barometric pressure of three cities, Islamabad, Lahore and Peshawar. Ambient design conditions for accurate assessment of weather induced cooling loads of residential and commercial buildings have been established, using commutative frequency of occurrence technique. Dry bulb temperature and wet bulb temperate values corresponding to 1%, 2.5 %, 5% and 10% frequency of occurrence from summer weather data often years from 1986 to 1995 are evaluated for the three cities. The calculated percentile frequency of occurrence is based on both 24-hour basis and 9 hours basis (day time basis ) for use with residential and commercial buildings respectively. Mean daily range of dry bulb temperature and wet bulb temperature is reported for each month of summer season. Mean daily maximum, mean daily minimum, mean monthly minimum and mean monthly maximum values of the two properties are also reported, for each month of the summer season. Psychrometric charts are constructed for the three cities based on the actual barometric pressure data of ten consecutive years of summer season. Summer weather data of the three cities is plotted on the psychrometric charts to draw the weather envelope of summer seasons for the said cities. Finally, conclusions are drawn for the use of passive and active methods of cooling and the use of data in the design of engineering equipment.