Heating, ventilating, and air conditioning systems shall be designed and installed so that make-up air intake and exhaust vents do not cause contamination of food, food-contact surfaces, equipment, or utensils and do not create air currents that cause difficulty in maintaining the required temperatures of potentially hazardous foods.
Source:
Section 114149.3, https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=HSC§ionNum=114149.3..