Indoor Air Quality

Fresh air enters the breathing zone first

ASHRAE 62-89R defines indoor air quality as a measure of the amount of ventilation that reaches the breathing zone

It classifies systems as follows:

• Cooling overhead 1.0 (0.83)
• Cooling & heating overhead 0.8 (0.66)
• Underfloor Air Distribution system 1.2 (1)

Floor delivery systems are more effective in delivering fresh air to the breathing zone than overhead systems