N.Y.C. Admin. Code § 27-838: § 27-838 Ventilation.

Fixed ventilation for combustion air to the incinerator room shall be provided by a louvered opening in a wall to outdoor air. When ducts are used, they shall be sized and installed so as to provide the amount of air required for combustion, taking into consideration head loss. Fans may be installed to deliver air to the incinerator room, provided they are in operation whenever the incinerator is in use. Louvers, ducts, and fans shall be sized to deliver at least two and one-half cfm of air for each pound per hour of refuse while burning is taking place. All duct work shall be installed in accordance with the requirements of subchapter thirteen of this chapter.