Ventilation control as a function of indoor and outdoor air quality.

The majority of urban pollution is traffic related and often shows daily variations with peaks occurring at rush hours. Poor outdoor air quality can affect the IAQ of local buildings that ventilate with polluted air. This is particularly applicable to buildings where AHU air intakes are at low level and adjacent to busy roads. The effect of pollution peaks can be minimized by ventilation control and this paper presents potential control techniques for periods when outdoor air quality is poor. It demonstrates the variable nature of traffic related pollution, the dynamics of pollution ingress via the ventilation system, pollutant types, control limits, sensing techniques and potential control strategies.