Article 8 Ventilation of Special Spaces

In occupancy group H-1, rooms or spaces in which persons are detained under restraint may be naturally ventilated by means meeting the intent of this subchapter.

Kitchens shall be ventilated as follows: (a) Kitchens located within dwelling units and having a floor area of greater than fifty-nine square feet shall have natural ventilation as prescribed in article six of this subchapter. When the floor area is fifty-nine square feet or less, the kitchen shall be ventilated by either of the following:

(1) Natural means complying with article six of this subchapter and further that the windows shall have a minimum width of twelve inches, a minimum area of thee square feet or ten per cent of the floor area of the space whichever is greater and so constructed that at least one-half of their required area may be opened. When the space is located at the top story the window or windows may be replaced with a skylight whose minimum width shall be twelve inches, whose minimum area shall be four square feet or one-eighth the floor area of the space whichever is greater and shall have ventilating openings of at least one-half of the required area of the skylight.

(2) Mechanical means exhausting at least two cfm of air per square foot of floor area. Where doors are used to separate the space the lower portion of each door shall have a metal grille containing at least forty-eight square inches of clean openings or in lieu of such grille two clear open spaces may be provided, each of at least twenty-four square inches, one between the bottom of each door and the floor and the other between the top of each door and the head jamb.

(b) Kitchens, except those located within dwelling units, and side spaces, where cooking of any kind is done, shall be ventilated by either of the following; provided that in no instance may there be any violation of the nuisance provisions of the health code.

(1) Natural means complying with article six of this subchapter and supplemented with auxiliary mechanical supply and exhaust ventilation adequate to remove the fumes and smoke from the cooking equipment when operating.

(2) Mechanical means exhausting at least three cfm of air per square foot of floor area, but in no case less than one hundred fifty cfm. Such air shall be exhausted through duct or chimney constructed in accordance with the provisions of subchapters thirteen through fifteen of this chapter.

(c) Kitchens, snack bars, or pantries, where the operation consists of heating or warming previously prepared food that was cooked elsewhere, or preparation of food in vending machines may be ventilated by either of the following:

(1) Natural ventilation complying with article six of this subchapter.

(2) Mechanical ventilation complying with article seven of this subchapter.

Bathrooms and toilet rooms shall be ventilated as follows:

(a) When ventilated by natural means, the natural ventilation sources shall comply with section 27-749 of article six of this subchapter and shall have an unobstructed free area of at least five per cent of the floor area. In no case shall the net free area of the ventilation sources be less than one and one-half square feet except that in occupancy groups H-1 and H-2, provided the ventilation opening conforming with section 27-749 of article six of this subchapter may be in a vent shaft provided that the net free area of the opening is not less than three square feet. The vent shaft cross-sectional area shall be increased by one-fifth of a square foot for every foot of height, but shall not be less than nine square feet in area and open to the outer air at the top; or, the vent shaft may be open at the sides above the roof, with louvres providing an equivalent net free area at the top, equal to the area of the shaft.

(b) By individual vent shafts or ducts constructed of noncombustible materials with a minimum cross-sectional area of one square foot and one-third additional square foot for each additional water closet or urinal above two in number. The upper termination of such ducts shall be equipped with a wind-blown ventilator cap.

(c) When a bathroom or toilet room is not ventilated by natural ventilation as required by this section, it shall be mechanically ventilated as follows:

(1) Rooms containing only one water closet or urinal shall be mechanically ventilated by an exhaust system capable of exhausting at least fifty cubic feet of air per minute. Means shall be provided for air ingress by louvres in the door, by undercutting the door, or by transfer ducts, grilles, or other openings.

(2) Rooms containing more than one water closet or urinal, and any auxiliary spaces such as those used in hand basins, slop sinks, and locker rooms, shall be mechanically ventilated by an independent exhaust system capable of exhausting at least forty cubic feet of air per minute per water closet or urinal. The outdoor air supply shall conform to the requirements of article seven of this subchapter.

(3) Toilet exhaust systems shall be arranged to expel air directly to the outdoors.

Inside locker rooms and dressing rooms for more than one person shall be provided with exhaust ventilation giving at least four changes of air per hour.

Unless natural sources complying with section 27-749 of article six of this subchapter provides ventilating openings equivalent to at least two and one-half percent of the floor area, corridors in buildings of occupancy groups H-1, J-1 and J-2 more than three stories in height, shall be mechanically ventilated by a system supplying at least one-half cubic foot of outdoor air per minute per square foot of floor area. When air conditioned, a part of the required supply may be recirculated as equivalent outdoor air, but at least thirty-three and one-third percent of the required air supply shall be actual outdoor air.

(a) Buildings and structures without basements. In buildings and structures constructed without basements, and in which the first floor construction does not bear directly on the ground, a space at least eighteen inches high shall be provided directly under the floor beams, girders or sill of the first floor construction. Where the floor above such a space is constructed of wood or metal, the space shall be ventilated by one of the following means:

(1) At least four widely-distributed ventilating openings, providing a total net free area of at least one eight-hundredth of the area of the crawl space, shall be provided in the foundation walls, and the ground within the crawl space shall be covered with a vapor barrier in durability equivalent to at least fifty-five pounds, roofing felt with unsealed laps and with a transmission rate of one perm or less. At least two ventilating openings, providing a total net free area of at least one fifteen-hundredth the area of the crawl space shall be provided in foundation walls, provided that a vapor barrier with a transmission rate of one perm or less is installed over the entire underside of the first floor construction and overlaps the walls.

(2) Other means acceptable to the commissioner.

(b) Buildings and structures with basements. No foundation wall vents shall be required where one side of a crawl space is completely open except for structural members, to a basement that has an area at least equivalent to that of the crawl space, provided that the basement is naturally ventilated by openings complying with section 27-749 of article six of this subchapter and having a free openable area of at least five per cent of the floor area of the basement.

Rooms containing refrigeration plants shall be ventilated in accordance with the provisions of subchapter thirteen of this chapter.

Boiler rooms shall be ventilated in a manner that will provide air for combustion in accordance with the provisions of subchapter fourteen of this chapter and also prevent the accumulation of hot air over or near the equipment within the room.

School buildings shall be ventilated in accordance with the following requirements:

(a) Rooms of instruction and administration. Classrooms, other rooms of instruction, and administrative rooms, where the index for ventilation is less than one thousand six hundred fifty, shall have a supply of outdoor air of at least fifteen cfm per occupant and mechanical exhaust. Where windows are used as the source of supply air, mechanical air exhaust shall be fifteen cfm per occupant. When outdoor air is supplied by mechanical means, the exhaust shall be at least eighty per cent of the supply. In air-conditioned rooms, the conditioned air supply may be reduced to a minimum of ten cfm per occupant, of which at least five cfm shall be outdoor air.

(b) Lockers and wardrobes. Lockers, wardrobes, or wardrobe rooms shall be ventilated in accordance with the provisions of section 27-760 of this article, and where these spaces are located within or adjacent to classroom, the exhaust air from the classroom may be used for such ventilation.

(c) Auditoria and assembly rooms. Rooms where there are more than seventy-five occupants shall have a supply of outdoor air of at least fifteen cfm per occupant and mechanical exhaust. Where windows are used as the source of supply air, mechanical air exhaust shall be at least fifteen cfm per occupant. When outdoor air is supplied by mechanical means, the mechanical exhaust shall be at least eighty per cent of the supply. In air-conditioning spaces, the conditioned air supply may be reduced to a minimum of ten cfm per occupant, of which at least five cfm shall be outdoor air.

In these rooms or spaces, prevention of all of the following conditions shall be considered in the design and installation of a ventilating system:

(a) Excessive temperatures that may be detrimental to the occupants.

(b) The danger of large concentrations of toxic substances in the air.

(c) The danger of large concentrations of airborne irritants an impurities, such as steam, gases, vapor, and dust, that may be injurious to health.

Where the exhausted air may contain toxic substances or strong objectional odors, the exhaust system shall be independent of exhaust systems serving other parts of the building.

Special uses and occupancies, not provided for in this subchapter, shall be ventilated in accordance with the requirements of subchapter seven of this chapter. Ventilation of stage areas shall be in accordance with the requirements of subchapter eight of this chapter.