Zone Air Distribution Effectiveness (Ez) is a measure of how effectively air distribution into a zone delivers ventilation to occupants. Ez is important to consider because not all delivery methods will get the ventilation air to the breathing zone, leaving occupants feeling stuffy and uncomfortable.
ASHRAE Standard 62.1 Table 6-4 defines the range of Ez values based on configuration and supply air temperatures. Because supply air temperatures are involved, an unique Ez can be defined for systems in heating and cooling. For more details about Zone Air Distribution Effectiveness please refer to the standard and user manual.