All rooms shall have sufficient tempered make-up air and exhaust ventilation to keep them free of excessive heat, steam, condensation, vapors, obnoxious odors, smoke, and fumes.
All ventilation systems, furnaces, gas- or oil-fired room heaters, and water heaters shall be designed, installed, and operated in accordance with the D.C. Plumbing Code (2008) incorporating the International Plumbing Code (2006) or most recent edition, as amended by the D.C. Plumbing Code Supplement (Subtitle F of 12 DCMR).
Each room in which food or drink is prepared, or in which utensils are washed, shall be provided with facilities for at least eight (8) air changes per hour. Recirculation of air is not permitted.
Each room in which food or drink is served shall be provided with facilities for at least five (5) air changes per hour, and not more than fifty percent (50%) recirculation of air shall be permitted.
Each cooking unit that creates smoke, steam, gases, fumes, odors, vapors, or excessive heat shall be hooded and vented, or locally vented to the outside air by forced draft, in a manner that effectively removes the conditions; provided, that small burners used intermittently for short periods of time, warming equipment, bread toasters, coffee urns, and radiant cooking units need not be so vented unless one (1) or more of the units creates a nuisance, or the Department determines the heating, ventilation, and air conditioning (HVAC) system does not adequately vent the room as specified in § 3009.3.
D.C. Mun. Regs. tit. 25, r. 25-A3009