Earth construction, courtyards, verandahs, and cooltowers: An Arizona ranch house with middle east vernacular

This paper documents a stand alone, remote ranch house in southeastern Arizona that is passively heated and cooled. Located about six miles from the nearest electric power, the ranch house serves as headquarters for a 15,000 acre ranch. The ranch house incorporates the remains of a turn-of-the-century adobe residence with contemporary technology. The new house consists of three modules arranged around a T-shaped courtyard with passages that run east-west and north-south. Although solar heating is necessary during the winter, the primary reason for the design was to assure adequate cooling for the extreme conditions of the summer. Two of the modules were constructed with 18 " stabilized rammed earth (suitable soil was mined from an adjacent represso) with a 1 " polystyrene external substrate for the integral color plaster. The original building was wrapped in steel studs, insulated, and received the same external treatment. Cooling is supplied by cooltowers which are integral to each module. The cooltowers are designed to provide sufficient airflow to change the air in each module once every two minutes. The T-shape courtyard is fully shaded on the north with ramada shading on the west. Each of the three ends of the T have barn doors that can be operated diurnally or seasonally to manage courtyard ventilation. When the barn doors are closed excess cooltower output fills the courtyard for additional summer comfort. Energy performance, ventilation strategies, water harvesting and a fully automated Photovoltaic system are described.