Studies on the geometrical properties of courtyard house form considering natural ventilation in hot-dry regions.

摘要

Courtyard houses have demonstrated successful design and planning solutions that address numerous cultural, social as well as environmental issues. This thesis deals with the thermal effects of the courtyard geometry in the hot dry regions, which have been the most to, environmentally, benefit from the courtyard concept. The earlier attempts to study the effect of the geometrical properties, which have focused on irradiation loads, are extended hereby to include the effect of natural ventilation.;The thermal effect of the courtyard geometry is investigated in terms of both the heat transferred and the thermal comfort measures within the surrounding spaces. An adaptive model of thermal comfort is utilized in order to provide a comprehensive thermal evaluation. Three of the geometrical parameters of the courtyard of the form are studied; the Courtyard Plan Aspect Ratio (CPAR), courtyard height and orientation. DOE2.1E, as a powerful simulation tool, is utilized to study nine variations of CPAR under the hot dry conditions of Phoenix, Arizona. Natural ventilation is simulated by introducing the outside air in four constant volumes, with both nocturnal and diurnal ventilation strategies. The effect of the courtyard height is included by comparing the performance of three schemes: one, two and three stories.;Results showed that increasing CPAR, for the same ventilation rate, increases the aggregate energy consumption and leads to less comfortable indoor conditions. The rate of change is marginal, particularly with higher rates of ventilation. The courtyard height has assumed more importance compared to CPAR; the aggregate heat transferred has decreased considerably in higher schemes.;The introduction of natural ventilation proved to be very crucial to the evaluation of the courtyard house thermal performance. Increasing air-changes resulted in a considerable increase in the diurnal temperature difference, comfort periods as well as the amount of heat transferred. However, these parameters have not generally been affected by the orientation. 45-degree orientation shows a slight difference from the other orientations. The research concludes with design guidelines regarding courtyard geometry and the possible design and planning applications of the findings.