Two Las Vegas hotel and casinos demonstrate new ways of thinking about smoke control.                  

This is the first of a series of four papers that describe a 3-year EU-funded research project into the application of passive downdraught evaporative cooling to nondomestic buildings. In this paper various evaporative cooling techniques are reviewed. By spraying fine droplets of water at the top of atria, a downdraught of air cooled by evaporation can be produced. Such direct evaporative cooling using an evaporation tower appears to be a suitable approach for partly displacing the need for air-conditioning in hot, dry climates.