Performance and economic analysis of air flow windows in a tropical climate.

An experimental study was conducted in Thailand to determine the thermal performance of twin glazed windows with dynamic insulation. The effects of blinds situated either between or outside the glazing were analysed. With an external blind, the heat transfer coefficient was 1.25 W/m2 deg C with natural convection and 0.6 W/m2 deg C for a flow of 20 m3/h (glass area 2.16 m2). The solar flux transmitted was evaluated analytically and experimentally depending on the blind's position. An economic study was performed on a six-storey air-conditioned building in Thailand. It showed in tropical countries that it may be more economical to use air flow windows than to have tinted single or double glass windows.