This chapter shall govern the ventilation of spaces within a building intended to be occupied. This chapter does not govern the requirements for smoke control systems (see Section 513 of this code.)
Every occupied space shall be ventilated by natural means in accordance with Section 402 or by mechanical means in accordance with Section 403.
Ventilation shall be provided during the periods that the room or space is occupied.
Outdoor air exhaust and intake openings shall be located a minimum of 10 feet (3048 mm) from lot lines or buildings on the same lot. Where openings front on a street or public way, the distance shall be measured to the centerline of the street or public way.

Exceptions:


1. Group R-3.
2. Exhaust outlets for environmental air exhaust openings shall be located not less than 3 feet (914 mm) from property lines and not less than 3 feet (914 mm) from openings into the building.
Mechanical and gravity outdoor air intake openings shall be located a minimum of 10 feet (3048 mm) horizontally from any hazardous or noxious contaminant source, such as vents, chimneys, plumbing vents, streets, alleys, parking lots and loading docks, except as otherwise specified in this code. Where a source of contaminant is located within 10 feet (3048 mm) horizontally of an intake opening, such opening shall be located a minimum of 2 feet (610 mm) below the contaminant source.

The exhaust from a bathroom or kitchen in a residential dwelling shall not be considered to be a hazardous or noxious contaminant.
Outdoor exhaust openings shall be located so as not to create a nuisance. Exhaust air shall not be directed onto walkways.
For structures located in flood hazard areas, outdoor exhaust openings and air intake openings shall be at or above the design flood elevation. [B]
Air exhaust and 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 exhaust and intake openings located in exterior walls shall meet the provisions for exterior wall opening protectives in accordance with the Building Code of New York State.

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
Exhaust openings Not < 1/4 inch and not > 1/2 inch
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.
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.
Natural ventilation of an occupied space shall be through windows, doors, louvers or other openings to the outdoors. The operating mechanism for such openings shall be provided with ready access so that the openings are readily controllable by the building occupants.
The minimum openable area to the outdoors shall be 4 percent of the floor area being ventilated.
Where rooms and spaces without openings to the outdoors are ventilated through an adjoining room, the opening to the adjoining rooms shall be unobstructed and shall have an area not less than 8 percent of the floor area of the interior room or space, but not less than 25 square feet (2.3 m2). The minimum openable area to the outdoors shall be based on the total floor area being ventilated.

Exception:
Exterior openings required for ventilation shall be permitted to open into a thermally isolated sunroom addition or patio cover, provided that the openable area between the sunroom addition or patio cover and the interior room has an area of not less than 8 percent of the floor area of the interior room or space, but not less than 20 square feet (1.86 m2). The minimum openable area to the outdoors shall be based on the total floor area being ventilated.
Where openings below grade provide required natural ventilation, the outside horizontal clear space measured perpendicular to the opening shall be one and one-half times the depth of the opening. The depth of the opening shall be measured from the average adjoining ground level to the bottom of the opening.
Mechanical ventilation shall be provided by a method of supply air and return or exhaust air. The amount of supply air shall be approximately equal to the amount of return and exhaust air. The system shall not be prohibited from producing negative or positive pressure. The system to convey ventilation air shall be designed and installed in accordance with Chapter 6.

Ventilation supply systems shall be designed to deliver the required rate of supply air to the occupied zone within an occupied space. The occupied zone shall have boundaries measured at 3 inches (76 mm) and 72 inches (1829 mm) above the floor and 24 inches (610 mm) from the enclosing walls.
The minimum ventilation rate of outdoor air shall be determined in accordance with Section 403.3.

Exception:
Where the registered design professional demonstrates that an engineered ventilation system design will prevent the maximum concentration of contaminants from exceeding that obtainable by the rate of outdoor air ventilation determined in accordance with Section 403.3, the minimum required rate of outdoor air shall be reduced in accordance with such engineered system design.
The air required by Section 403.3 shall not be recirculated. Air in excess of that required by Section 403.3 shall not be prohibited from being recirculated as a component of supply air to building spaces, except that:
1. Ventilation air shall not be recirculated from one dwelling to another or to dissimilar occupancies.
2. Supply air to a swimming pool and associated deck areas shall not be recirculated unless such air is dehumidified to maintain the relative humidity of the area at 60 percent or less. Air from this area shall not be recirculated to other spaces where 10 percent or more of the resulting supply airstream consists of air recirculated from these spaces.
3. Where mechanical exhaust is required by Note b in Table 403.3, recirculation of air from such spaces shall be prohibited. All air supplied to such spaces shall be exhausted, including any air in excess of that required by Table 403.3.
4. Where mechanical exhaust is required by Note h in Table 403.3, mechanical exhaust is required and recirculation is prohibited where 10 percent or more of the resulting supply airstream consists of air recirculated from these spaces.
Except where recirculation from such spaces is prohibited by Table 403.3, air transferred from occupied spaces is not prohibited from serving as makeup air for required exhaust systems in such spaces as kitchens, baths, toilet rooms, elevators and smoking lounges. The amount of transfer air and exhaust air shall be sufficient to provide the flow rates as specified in Sections 403.3 and 403.3.1. The required outdoor air rates specified in Table 403.3 shall be introduced directly into such spaces or into the occupied spaces from which air is transferred or a combination of both.
Ventilation systems shall be designed to have the capacity to supply the minimum outdoor airflow rate determined in accordance with Table 403.3 based on the occupancy of the space and the occupant load or other parameter as stated therein. The occupant load utilized for design of the ventilation system shall not be less than the number determined from the estimated maximum occupant load rate indicated in Table 403.3. Ventilation rates for occupancies not represented in Table 403.3 shall be determined by an approved engineering analysis. The ventilation system shall be designed to supply the required rate of ventilation air continuously during the period the building is occupied, except as otherwise stated in other provisions of the code.

Exception:
The occupant load is not required to be determined, based on the estimated maximum occupant load rate indicated in Table 403.3 where approved statistical data document the accuracy of an alternate anticipated occupant density.

TABLE 403.3 REQUIRED OUTDOOR VENTILATION AIR

 


OCCUPANCY
CLASSIFICATION
ESTIMATED MAXIMUM OCCUPANT LOAD, PERSONS PER 1,000 SQUARE FEETa  OUTDOOR AIR [Cubic feet per minute (cfm) per person] UNLESS NOTEDe
Correctional facilities    
  Cells    
    without plumbing fixtures 20  20
    with plumbing fixturesg, h 20  20
  Dining halls 100  15
  Guard stations 40  15
Dry cleaners, laundries    
  Coin-operated dry cleaner 20 15
  Coin-operated laundries 20 15
  Commercial dry cleaner 30 30
  Commercial laundry 10 25
  Storage, pick up 30 35
Education    
  Auditoriums 150 15
  Classrooms 50 15
  Corridors 0.10 cfm/ft2
  Laboratories 30 20
  Libraries 20 15
  Locker roomsh 0.50 cfm/ft2
  Music rooms 50 15
  Smoking loungesb,g 70 60
  Training shops 30 20
Food and beverage service    
  Bars, cocktail lounges 100 30
  Cafeteria, fast food 100 20
  Dining rooms 70 20
  Kitchens (cooking)f,g 20 15
Hospitals, nursing and
convalescent homes
   
  Autopsy roomsb 0.50 cfm/ft2
  Medical procedure rooms 20 15
  Operating rooms 20 30
  Patient rooms 10 25
  Physical therapy 20 15
  Recovery and ICU 20 15
Hotels, motels, resorts
and dormitories
   
  Assembly rooms 120 15
  Bathroomsg, h 35
  Bedrooms 30 cfm per room
  Conference rooms 50 20
  Dormitory sleeping areas 20 15
  Gambling casinos 120 30
  Living rooms 30 cfm per room
  Lobbies 30 15
Offices      
  Conference rooms 50 20
  Office spaces 7 20
  Reception areas 60 15
  Telecommunication    
    centers and data entry 60 20 

(continued)


TABLE 403.3—continued REQUIRED OUTDOOR VENTILATION AIR


OCCUPANCY
CLASSIFICATION
ESTIMATED MAXIMUM OCCUPAN
LOAD, PERSONS PER 1,000 SQUARE FEETa
OUTDOOR AIR (Cubic feet per minute (cfm) per person)
UNLESS NOTEDe
Private dwellings, single and
multiple
   
  Garages, common for 1.5 cfm/ft2
    multiple unitsb    
  Garages, separate for each 100 cfm per car
    dwelling    
  Kitchensg 100 cfm intermittent or
25 cfm continuous
  Living areasc Based upon number
of bedrooms. first
bedroom: 2; each
additional
bedroom: 1
0.35 air changes
per houra or 15cfm
per person, whichever is
greater
  Toilet rooms and
      bathroomsg, h
Mechanical
exhaust capacity
of 50 cfm
intermittent or
20 cfm continuous  
Public spaces    
  Corridors and utilities 0.05 cfm/ft2
  Elevator carg 1.00 cfm/ft2
  Locker roomsh 0.5 cfm/ft2
  Shower rooms
     (per shower head)g,h
50 cfm
intermittent or
20 cfm continuous
  Smoking loungesb,g 70 60
  Toilet roomsg,h   75 cfm per water
closet or urinal
Retail stores, sales floors and
showroom floors
   
  Basement and street 0.30 cfm/ft2
  Dressing rooms 0.20 cfm/ft2
  Malls and arcades 0.20 cfm/ft2
  Shipping and receiving 0.15 cfm/ft2
  Smoking loungesb 70 60
  Storage rooms 0.15 cfm/ft2
  Upper floors 0.20 cfm/ft2
  Warehouses 0.05 cfm/ft2
Specialty shops
 
 
  Automotive motor- fuel-    
    dispensing stations 1.5 cfm/ft2
  Barber 25 15
  Beauty 25 25
  Clothiers, furniture 0.30 cfm/ft2
  Embalming roomb 2.0 cfm/ft2
  Florists 8 15
  Hardware, drugs, fabrics 8 15
  Nail salonb, i 50 cfm
intermittent or 20
cfm continuous
per station
  Pet Shops 1.00 cfm/ft2
  Reducing salons 20 15
  Supermarkets 8 15 

(continued)


TABLE 403.3—continued REQUIRED OUTDOOR VENTILATION AIR


OCCUPANCY
CLASSIFICATION
ESTIMATED MAXIMUM OCCUPANT LOAD, PERSONS PER 1,000 SQUARE FEETa OUTDOOR AIR (Cubic feet per minute (cfm) per person)
UNLESS NOTEDe
 
Sports and amusement    
  Ballrooms and discos 100 25
  Bowling alleys (seating areas) 70 25
  Game rooms 70 25
  Ice arenas 0.50 cfm/ft2
  Playing floors (gymnasiums) 30 20
  Spectator areas 150 15
  Swimming pools (pool and 0.50 cfm/ft2 
    deck area)    
Storage    
  Repair garages, enclosed    
    parking garagesd 1.5 cfm/ft2
  Warehouses 0.05 cfm/ft2
Theaters    
  Auditoriums 150 15
  Lobbies 150 20
  Stages, studios 70 15
  Ticket booths 60 20
Transportation    
  Platforms 100 15
  Vehicles 150 15
  Waiting rooms 100 15
Workrooms    
  Bank vaults 5 15
  Darkrooms 0.50 cfm/ft2
  Duplicating, printing 0.50 cfm/ft2
  Meat processingc 10 15
  Pharmacy 20 15
  Photo studios 10 15


For SI: 1 cubic foot per minute = 0.0004719 m3/s, 1 ton = 908 kg,
           1 cubic foot per minute per square foot = 0.00508 m3/(s • m2),
           °C = [(°F) -32]/1.8, 1 square foot = 0.0929 m2.
   
a. Based upon net floor area.
   
b. Mechanical exhaust required and the recirculation of air from such spaces as permitted by Section 403.2.1 is prohibited (see Section 403.2.1, Items 1 and 3).
   
c. Spaces unheated or maintained below 50°F are not covered by these requirements unless the occupancy is continuous.
   
d. Ventilation systems in enclosed parking garages shall comply with Section 404.
   
e. Where the ventilation rate is expressed in cfm/ft2, such rate is based upon cubic feet per minute per square foot of the floor area being ventilated.
   
f. The sum of the outdoor and transfer air from adjacent spaces shall be sufficient to provide an exhaust rate of not less than 1.5 cfm/ft2.
   
g. Transfer air permitted in accordance with Section 403.2.2.
   
h. Mechanical exhaust is required and recirculation is prohibited except that recirculation shall be permitted where the resulting supply airstream consists of not more than 10 percent air recirculated from these spaces (see Section 403.2.1, Items 2 and 4).
   
i. The required exhaust system shall capture the contaminants and odors at their source.
The minimum flow rate of outdoor air that the ventilation system must be capable of supplying during its operation shall be permitted to be based on the rate per person indicated in Table 403.3 and the actual number of occupants present.
Where spaces having different ventilation rate requirements are served by a common ventilation system, the ratio of outdoor air to total supply air for the system shall be determined based on the space having the largest outdoor air requirement or shall be determined in accordance with the following formula:





(Equation 4-1)

where



Y = Vot /Vst = Corrected fraction of outdoor air in system supply.
X = Von /Vst = Uncorrected fraction of outdoor air in system supply.
Z = Voc /Vsc = Fraction of outdoor air in critical space. The critical space is that space with the greatest required fraction of outdoor air in the supply to this space.
Vot = Corrected total outdoor airflow rate.
Vst = Total supply flow rate, i.e., the sum of all supply for
all branches of the system.
Von = Sum of outdoor airflow rates for all branches on
system.
Voc = Outdoor airflow rate required in critical spaces.
Vsc = Supply flow rate in critical space.
Variable air volume air distribution systems, other than those designed to supply only 100-percent outdoor air, shall be provided with controls to regulate the flow of outdoor air. Such control system shall be designed to maintain the flow of outdoor air at a rate of not less than that required by Section 403 over the entire range of supply air operating rates.
Ventilation systems shall be balanced by an approved method. Such balancing shall verify that the ventilation system is capable of supplying the airflow rates required by Section 403.
Mechanical ventilation systems for enclosed parking garages shall be permitted to operate intermittently where the system is arranged to operate automatically upon detection of vehicle operation or the presence of occupants by approved automatic detection devices.
Automatic operation of the system shall not reduce the ventilation rate below 0.05 cfm per square foot (0.00025 m3/s • m2) of the floor area and the system shall be capable of producing a ventilation rate of 1.5 cfm per square foot (0.0076m3/s • m2) of floor area.
Connecting offices, waiting rooms, ticket booths and similar uses that are accessory to a public garage shall be maintained at a positive pressure and shall be provided with ventilation in accordance with Section 403.3.
Mechanical ventilation systems shall be provided with manual or automatic controls that will operate such systems whenever the spaces are occupied. Air-conditioning systems that supply required ventilation air shall be provided with controls designed to automatically maintain the required outdoor air supply rate during occupancy.
Uninhabited spaces, such as crawl spaces and attics, shall be provided with natural ventilation openings as required by the Building Code of New York State or shall be provided with a mechanical exhaust and supply air system. The mechanical exhaust rate shall be not less than 0.02 cfm per square foot (0.00001 m3/s • m2) of horizontal area and shall be automatically controlled to operate when the relative humidity in the space served exceeds 60 percent.
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