The design and control of buildings with passive downdraught evaporative cooling.

This paper describes part of an EC funded Joule project in which computer simulation has been used to investigate the viability of applying passive downdraught evaporative cooling (PDEC) to non-domestic buildings in hot dry climates. Using analytical techniques, CFO and thermal simulation, the performance-driven anatomy of PDEC buildings has been elucidated and engineering sizing methods have been developed. It is concluded that PDEC should formulate part of an holistic and carefully integrated solution. Its success is contingent upon the need to obviate wind and for many locations mechanical cooling support should be specified to ensure year-around occupant comfort. Nevertheless, water consumption is sufficiently low and energy savings are sufficiently high to warrant its increased application.