N.Y.C. Admin. Code § MC 401: Section MC 401: General

401.1 Scope.

This chapter shall govern the ventilation of spaces within a building intended to be occupied. Mechanical exhaust systems, including exhaust systems serving clothes dryers and cooking appliances; hazardous exhaust systems; dust, stock and refuse conveyor systems; subslab soil exhaust systems; smoke control systems; energy recovery ventilation systems and other systems specified in Section 502 shall comply with Chapter 5.

401.2 Ventilation required.

Habitable and occupiable spaces shall be provided with ventilation in accordance with this section.

1. Every occupiable space shall be:

1.1. Naturally ventilated in accordance with Section 402 and mechanically exhausted in accordance with Table 403.3.1.1; or

1.2. Mechanically ventilated in accordance with Section 403.

2. All habitable spaces and occupiable spaces provided with air conditioning shall be mechanically ventilated in accordance with Section 403.

3. Every habitable space shall be naturally ventilated in accordance with Section 402.

4. Every habitable space shall be mechanically ventilated if required by Section 403.

Ambulatory care facilities (Group B) and Group I-2 occupancies shall be ventilated by mechanical means in accordance with Section 407.

401.3 When required.

Ventilation shall be provided during the periods that the room or space is occupied or during operation of gas appliances.

401.4 Intake opening location.

Ventilation air intake openings shall comply with all of the following:

1. Intake openings shall be located not less than 10 feet (3048 mm) from lot lines or buildings on the same lot. For buildings on lots measuring less than 20 feet (6096 mm) in width, intake openings shall be located at the centerline between lot lines. Where openings front on a street or public way, the distance shall be measured to the centerline of the street or public way.

2. Outdoor air intakes for office occupancies having occupied floors located more than 75 feet (22 860 mm) above the lowest level of fire department vehicle access serving spaces above the second story and serving spaces greater than 10,000 square feet (929 m

2

) of floor area shall be located at least 20 feet (6096 mm) above ground level, at least 30 feet (9144 mm) from exhaust outlets and other exhaust discharges, and at least 20 feet (6096 mm) from areas that may collect vehicular exhaust, such as off street loading bays.

3. Mechanical and gravity outdoor air intake openings shall be located not less than 10 feet (3048 mm) horizontally from any hazardous or noxious contaminant source, such as vents, exhausts (including but not limited to exhaust from dry cleaning establishments, spray booths, and cooling towers), streets, alleys, parking lots and loading docks, except as specified in Item 3 of Section 501.3.1. Outdoor air intake openings shall be permitted to be located less than 10 feet (3048 mm) horizontally from streets, alleys, parking lots and loading docks provided that the openings are located not less than 25 feet (7620 mm) vertically above such locations. Where openings front on a street or public way, the distance shall be measured to the centerline of the street or public way.

4. Where the requirements of Item 3 above cannot be achieved, intake openings shall be located not less than 3 feet (914.4 mm) below contaminant sources where such sources are located within 10 feet (3048 mm) of the opening.

5. Intake openings in Group I occupancies shall comply with ANSI/ASHRAE/ASHE 170, as required.

6. Intake openings on structures in flood hazard areas shall comply with the additional requirements of Appendix G of the New York City Building Code.

Exception: Group R-3 occupancies are not required to comply with Section 401.4.

401.4.1 Required dampers in intake openings.

Outdoor air intakes shall be provided with dampers in accordance with Chapter 6.

401.5 Intake opening protection.

Air intake openings that terminate outdoors shall be protected with corrosion-resistant screens, louvers or grilles. Openings in louvers, grilles and screens shall be sized in accordance with Table 401.5, and shall be protected against local weather conditions. Outdoor air intake openings located in exterior walls shall meet the provisions for exterior wall opening protectives in accordance with Section 705 of the New York City Building Code.

Table 401.5 Opening Sizes in Louvers, Grilles and Screens Protecting Outdoor Exhaust and Air Intake Openings

Outdoor Opening Type

Minimum and Maximum Opening Sizes in Louvers, Grilles and Screens Measured in Any Direction

Intake openings in residential occupancies

Not < 1/4 inch and not > 1/2 inch

Intake openings in other than residential occupancies

> 1/4 inch and not > 1 inch

For SI: 1 inch = 25.4 mm.

401.6 Contaminant sources.

Stationary local sources producing air-borne particulates, heat, odors, fumes, spray, vapors, smoke or gases in such quantities as to be irritating or injurious to health shall be provided with an exhaust system in accordance with Chapter 5 or a means of collection and removal of the contaminants. Such exhaust shall discharge directly to an approved location at the exterior of the building.

401.6.1 Wind-driven rain.

All exterior louvers for building ventilation systems shall conform to the requirements of Chapter 16 of the New York City Building Code, where applicable, and the following:

1. Comply with the requirements of AMCA 550. Louvers shall comply with the intrusion requirements of wind-driven rain without the use of a damper. Outdoor air intake openings located in exterior walls shall meet the provisions for exterior wall opening protectives in accordance with Chapter 16 of the New York City Building Code; or

2. Be installed on a plenum configured to intercept any wind-driven rain penetrating the louver and to prevent the rain from entering the building ductwork system. Such plenum shall be waterproofed and equipped with a drainage system to convey water penetrating the louver directly to the outdoors or in accordance with the New York City Plumbing Code.