Air movement limits have changed in the updated version of ANSI/ASHRAE Standard 55, Thermal Environmental Conditions for Human Occupancy. The changes are based on research that shows most occupants prefer more air movement than currently provided. This preference holds regardless of whether a space is perceived as warm, neutral or slightly cool. This article was written by the chair and longtime members of the Standard 55 committee. It covers the ASHRAE-sponsored research that assembled a database of occupant studies and the procedures for establishing a comfort zone for temperature, radiation, humidity and air movement. It also covers criteria for options with and without local control.

Units: Dual