A recent report has documented the emergence of diverse air-conditioning products with enhanced dehumidifi cation features. The leading issue being addressed with these new cooling systems is the large dehumidifi cation requirement presented by moisture-laden outside air that is mechanically introduced into buildings to meet the increased ventilation rates of ANSI/ASHRAE Standard 62-1989, Ventilation for Acceptable Indoor Air Quality, and its revisions over the last 15 years.