(1) All rooms must have sufficient ventilation to keep them free of excessive heat, steam, condensation, vapors, obnoxious odors, smoke and fumes. When vented to the outside, the system may not create an unsightly, harmful or unlawful discharge.

(2) Intake and exhaust air ducts must be maintained to prevent the entrance of dust, dirt, and other contaminating materials.

(3) In new or extensively remodeled establishments, all rooms from which obnoxious odors, vapors or fumes originate must be mechanically vented to the outside.