Establish feasibility for providing passive cooling with solar updraft and evaporative downdraft chimneys

Abstract

Natural draft towers can be used for cooling and ventilatingstructures. From an operational perspective,the downdraft evaporatively cooled tower is preferred for a dry climate. Solar chimneys, when used alone, tend to require an excessively large solar collector area when appreciable quantities of air must be moved. When used m combination with a downdraft tower, the roof and attic of buildings may assistthe solar chimney and their use becomes more attractive. Both a frame building and a greenhouse were successfully cooled during this program. The economms of the downdraft tower compare favorably with conventional evaporative coolingforsome applications.

Innovations in Passive Downdraft Cooling Performance Evaluation Methods: Design and Construction of a Novel Environmental Test Chamber

“…and then evolving to be integrated with the outlets of wind towers in the desert regions of Iran in the early tenth century [6]. Innovations in wind tower design came in the 1980s when a rigid media direct evaporative cooling system was placed at the top of the tower, causing heavier, cooler air to drop downwards by gravity; hence, the design was named the passive downdraft evaporative cooling tower (PDECT) [7].…”

Wind-induced evaporative cooling passive system for tropical hot and humid climate

“…According to Bowman et al (2000), the desired size of droplets of water is then pushed forward into the air stream and the droplets experienced heat, mass, and momentum transfer processes. This technique was tested on a domestic-scale lightweight test building by Cunningham (1986). In their experiment, the peak ambient dry bulb temperature was 40.5 °C, wet bulb temperature was 21.3 °C, and air exited at 23.8 °C at a rate of 30 ACH while maintaining an average indoor temperature of 24.6 °C.…”