Refers to the ANSI/ASHRAE Standard 62-1989 - Ventilation for Acceptable Indoor Air Quality, which substantially increases the ventilation requirements for commercial buildings including retail establishments. Describes the results of a one-year monitored evaluation of a gas-fired desiccant makeup air system used in a Wal-Mart super centre, as compared with the operation of a conventional system in a nearly identical store. The system provides continuous fresh air ventilation and independent temperature and humidity control. It also demonstrates the potential for energy savings and reduced first cost of the HVAC system. Presents some of the findings, which confirm that the desiccant approach has proved to be a cost effective solution to the new ventilation problem. On the basis of the findings supplies design recommendations.