Outdoor Air Intake Flow
The limit for carbon monoxide concentration is 30 ppm for an 8 hr average and 75 ppm for a 15 min average.
Outdoor air intake flow. Ot shall be determined in accordance with sections 6 3 1 through 6 3 5. Find outdoor air intake flow vot the final step is to calculate the outdoor air intake flow vot by dividing the uncorrected outdoor air intake vou by the highest system ventilation efficiency ev. Install controls to provide intermittent fresh air based on a timer. If a sensor in the intake air stream detects an unacceptable leve l of some substance the outdoor air dampers are closed until the c ondition passes.
For our example the summation of vbz 600 cfm ev 0 6 then the outdoor air intake 6000 6 1000 cfm. Contaminants or mixtures of concern for purposes of the design shall be identified. The minimum supply air flow rate is 2 7 liter s m 2. It includes outdoor intake air and recirculated air from that air handling unit but does not include air transferred or air recirculated to the zone by other means.
Australian standard 9 specifies that a minimum flow rate of fresh air of 3000 liter s is to be maintained. For each contaminant or mixture of concern indoor sources occupants and materials and outdoor sources shall be identified and the. Vot 700 cfm 0 65 1077 cfm for this example 1077 cfmof unconditioned outdoor air is required to adequately ventilate all spaces. The airflow rate supplied to the zone from the airhandling unit at which the outdoor air intake is located.
V pz primary airflow. Set the timer to meet desired or code mandated ventilation requirements. When an outdoor air inlet is ducted to the return side of the hvac system s central air handler install a motorized damper that can close the air intake. This rate would require 9 72 air changes per hour per meter length of ceiling height.