18-28-403.1.3 Systems with water economizers.
   If a system is equipped with a water economizer in accordance with the Chicago Energy Conservation Code, the amount of outside air delivered by the mechanical air handling system shall be no less than 1/3 of the code-required supply air. The area of the outside air intake shall be sized so that at least 1/3 of the code-required supply air can be taken from outdoors at velocities not in excess of 1,000 feet per minute (304.8 mpm) through the free area. The remaining air may be supplied by a recirculating air system if the system is equipped with devices to control temperature and dust content. The total quantity of air delivered to the space shall be 100 percent of the code-required air.
(Amend Coun. J. 9-14-21, p. 35949, Art. IV, § 3)