The impact of densification on air-conditioning loads in a dry environment: Using a semi-empirical model for street canyon temperatures as input for thermal simulations

The open-air scaled urban surface (OASUS) model consists of an extensive scaled urban array constructed at an open site in the Negev desert of Israel. Building rows are comprised of 0.2×0.2×0.4m hollow concrete masonry blocks and have thermal and optical properties analogous to common local construction materials in the Negev area. From experimental data, gathered from summer measurements in OASUS, a semi-empirical model was developed, which predicts among other variables temperatures within scaled street canyons of given geometry based on ambient conditions above the urban canopy. In this paper, the semi-empirical model is presented and compared to actual measurements at OASUS in summer 2006. Predicted street canyon temperatures for varying aspect ratios (H/W of 0.33, 0.66, 1 and 2), were used as input data in a thermal and energy simulation environment in order to analyze the effect of densification on energy consumption for air-conditioning in a given building.