Impact of densification and solar orientation of urban canyons on energy demand for air-conditioning under desert climatic conditions

Abstract

The purpose of this study was to analyze the effect of urban shape on the energy used for air-conditioning in buildings, in order to ensure indoor comfort during summer. The method considers energy consumption calculations for a massive, two-storied building, located at Sede Boqer (latitude 30° 52' 0N, longitude 34° 46' 60E, and altitude 480 m above sea level), campus of the Ben-Gurion University of the Negev, Israel. Thermal simulations for different urban canyon configurations were applied. The two-storied building was monitored from January until the end of August 2006, and the monitoring results were used for calibrating a simulation model with the software Indoor Climate and Energy (IDA). As part of the input data, Canyon Air Temperature model (CAT) was used for predicting local canyon temperatures for different street canyons. Predicted and measured temperatures at a street canyon in Sede Boqer were compared, calibrating CAT for summer conditions. Finally, after calibrating the IDA simulation model and the CAT model, the following canyon configurations were considered for analysis: NS and EW street axis orientations; street axis perpendicular (PERP) and parallel (PARAL) to prevailing wind direction, and aspect ratios (H/W) of 0.33, 0.66, 1 and 2. Results provide possible guidelines for the geometric definition of urban canyons and the management of a high thermal mass building under desert conditions.