Municipal Code of Chicago § 18-28-401.1 Scope.
18-28-401.1 Scope.
This article shall govern the ventilation of spaces within a building intended to be occupied.
Ventilation (18-28-401 et seq.)
Municipal Code of Chicago tit. 18, ch. 18-28, art. IV
in effectMunicipal Code of Chicago § 18-28-401.2 Ventilation required.
18-28-401.2 Ventilation required.
Every occupied space shall be ventilated by natural means in accordance with Section 18-28-402 or by mechanical means in accordance with Section 18-28-403.
Municipal Code of Chicago § 18-28-401.3 When required.
18-28-401.3 When required.
Ventilation shall be provided during the periods that the room or space is occupied.
Municipal Code of Chicago § 18-28-401.4 Method of producing ventilation.
18-28-401.4 Method of producing ventilation.
Ventilation may be produced by:
1. A natural ventilating system which is hereby defined as a system, the effectiveness of which depends upon natural atmospheric conditions and upon the operation of windows, transoms and other openings, the operation of which is in control of the person or persons in the room or space which is ventilated.
2. A mechanical ventilating supply system, which is hereby defined as a system for forcing air into a room or space by artificial means combined with the removal of air through windows, skylights, transoms, undercut doors, grilles, shafts, ducts, or other relief openings direct to outside atmosphere except as provided in Table 18-28-403.3.
3. A mechanical ventilating exhaust system, which is hereby defined as a system for removing air from a room or space by artificial means combined with a supply of air through windows, skylights, transoms, grilles, shafts, ducts or other relief openings direct to outside atmosphere except as provided in Table 18-28-403.3.
Municipal Code of Chicago § 18-28-401.5 Reserved. Editor's note – Coun. J. 9-14-21, p. 35949, Art. IV, § 1, repealed § 18-28-401.5, which pertained to ventilation openings.
Municipal Code of Chicago § 18-28-401.5.1 Reserved. Editor's note – Coun. J. 9-14-21, p. 35949, Art. IV, § 1, repealed § 18-28-401.5.1, which pertained to area of the openings.
Municipal Code of Chicago § 18-28-401.5.1.1 Reserved. Editor's note – Coun. J. 9-14-21, p. 35949, Art. IV, § 1, repealed § 18-28-401.5.1.1, which pertained to windows.
Municipal Code of Chicago § 18-28-401.5.1.2 Reserved. Editor's note – Coun. J. 9-14-21, p. 35949, Art. IV, § 1, repealed § 18-28-401.5.1.2, which pertained to skylights.
Municipal Code of Chicago § 18-28-401.5.1.3 Reserved. Editor's note – Coun. J. 9-14-21, p. 35949, Art. IV, § 1, repealed § 18-28-401.5.1.3, which pertained to transoms.
Municipal Code of Chicago § 18-28-401.5.1.4 Reserved. Editor's note – Coun. J. 9-14-21, p. 35949, Art. IV, § 1, repealed § 18-28-401.5.1.4, which pertained to auxiliary ventilating openings.
Municipal Code of Chicago § 18-28-401.5.1.5 Relief openings.
18-28-401.5.1.5 Relief openings.
Relief openings (RO) as used in Table 18-28-403.3 as set out in Section 18-28-403.3, shall be considered to be any duct that connects a room to the outside. Relief openings for ductwork shall be of sufficient cross sectional area so that maximum velocity shall not exceed 800 feet per minute. Relief openings in ducts for exhaust may extend in a horizontal direction for a distance not to exceed 5 feet.
Municipal Code of Chicago § 18-28-401.5.1.6 Air quantities.
18-28-401.5.1.6 Air quantities.
The quantity of air supplied or exhausted through any relief opening shall not be less than the quantity specified in Section 18-28-403.3 for mechanical supply or mechanical exhaust systems. The termination of the duct shall be equipped with a storm-proof louver, cowl, or other equipment opening having an outlet free area not smaller than that of the duct.
Municipal Code of Chicago § 18-28-401.5.1.7 Damper.
18-28-401.5.1.7 Damper.
The duct may be equipped either with a gravity type damper that permits air to flow in one direction only; or with an automatic damper that closes only when the fan serving the room is not running, or both.
Municipal Code of Chicago § 18-28-401.5.2 Opening location.
18-28-401.5.2 Opening location.
The intake opening which draws air from the outside atmosphere shall be located at a point that prevents contamination of the air supply and shall be unobstructed at all times. The intake opening shall be located not less than 15 feet from the discharge outlet of any exhaust fan, plumbing vent and chimney or similar object. Unless adequate means are provided to remove dust from the air, the bottom of the intake opening shall be not less than 10 feet above the surface of any abutting public way, gangway, driveway, grade, or abutting roof. No intake opening shall be placed in a horizontal position in any sidewalk, or in the pavement of any street, alley, or driveway, or within 12 inches of the level of any other surrounding grade; nor shall any intake opening take air from the lower level of any two-level street or similar construction. In loading docks, intake openings shall be located not less than 10 feet horizontally or vertically from any loading dock door.
Exceptions:
1. Interior loading spaces and appurtenant driveways. No ventilation openings for loading spaces and appurtenant driveways shall be required if the following conditions are met:
1.1 Loading spaces and appurtenant driveways are used in manufacturing, storage or mercantile units;
1.2 Doors open directly to the outside atmosphere at each loading space;
1.3 The loading dock is raised at least 36 inches above the adjacent driveway;
1.4 The doors are situated no more than 65 feet from the dock; and
1.5 The dock area is separated from the interior of the unit by a wall or door or by both.
2. No ventilation openings for exterior loading spaces and appurtenant driveways shall be required if the following conditions are met:
2.1 The loading dock is constructed with the floor of the dock not less than 36 inches above the adjacent driveway; and
2.2 The driveway is not enclosed; and
2.3 At least 20 percent of the lineal footage of the total external wall of the dock or 50 percent of the lineal footage of the largest external wall of the dock consists of loading doors.
Municipal Code of Chicago § 18-28-401.5.3 Points of exhaust discharge.
18-28-401.5.3 Points of exhaust discharge.
The air removed by every mechanical ventilating exhaust system shall be discharged outside at a point where it will not cause a nuisance, and from which it cannot again be readily drawn in by a ventilating system.
Exceptions:
1. Air which will not cause a nuisance may be discharged into a boiler room in such quantity as is required to supply the needs of combustion.
2. Air which will not cause a nuisance may be discharged into a garage used for active storage of only five or more cars, provided the garage is separately ventilated during all hours of occupancy, in accordance with the provisions of Section 18-28-403.3.
2.1 Provisions shall be made in cases as described above so that when an air system is used for smoke exhaust, the smoke shall be automatically discharged to the outside and the secondary use of the air is automatically dampered off.
Municipal Code of Chicago § 18-28-401.6 Outdoor air opening and protection.
18-28-401.6 Outdoor air opening and protection.
Air intake and exhaust that terminate outdoors shall be suitably protected against Chicago weather conditions, with corrosion resistant screens, louvers and grilles. Area of the outside air intake shall be sized so that at least 100 percent of the code-required outside air as required in Section 18-28-403.1 can be taken from outside at velocities not in excess of 1,000 feet per minute (304.8 mpm) through free area except for systems defined in paragraph 18-28-403.1.3.
Table 18-28-401.6
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 less than 1/4 inch and not greater than 1/2 inch
Intake openings in residential occupancies | Not less than 1/4 inch and not greater than 1/2 inch
Intake openings in other than residential occupancies | Not less than 1/4 inch and not greater than 1 inch
For SI: 1 inch = 25.4 mm.
Municipal Code of Chicago § 18-28-401.7 Additional ventilation.
18-28-401.7 Additional ventilation.
If the air condition in any habitable room becomes objectionable due to causes other than the occupancy by human beings, and the Building Commissioner finds that the health and comfort of the human occupants is endangered, additional ventilation by natural or mechanical means shall be provided in accordance with Article 5, Exhaust Systems, or as approved by the Building Commissioner.
Municipal Code of Chicago § 18-28-402.1 Natural ventilation.
18-28-402.1 Natural ventilation.
Natural ventilation shall comply with Chapter 12 of the Chicago Building Code.
(Amend Coun. J. 4-10-19, p. 100029, Art. XII, § 3; Amend Coun. J. 9-14-21, p. 35949, Art. IV, § 2)
Municipal Code of Chicago § 18-28-403.1 Source of air supply.
18-28-403.1 Source of air supply.
The air supply for every ventilation system, either natural or mechanical, shall be taken from out of doors, except in the following situations:
Exceptions:
1. Recirculation. When air is supplied by a mechanical ventilating supply system, a portion of the code required air supply may be recirculated, provided the system is equipped with such devices for control of temperature and dust content in the spaces to be ventilated and that the conditions of the air so supplied, (except as to temperature) are substantially the same as though all of the supply air were taken from out-of-doors. Under such conditions, not less than thirty-three and one-third percent of the Code requirements shall be taken from out-of-doors by the mechanical ventilating supply system; and sixty-six and two-thirds percent of the code requirements may be recirculated air, plus any additional air volume of system design capacity in excess of code requirements.
2. When air is supplied by a mechanical ventilating supply system which is not equipped with devices prescribed in paragraph 1, then only such portions of the air volumes of the system design capacity in cfm that exceed the total code requirements in cfm may be recirculated during the time of room occupancy. The air intake and all equipment and ducts shall be so arranged that all of the code required air supplied by the system can be taken from outside, with provisions made for release or exhaust of such air to the atmosphere.
3. Prohibited exhaust. No air exhausted from bath, toilet, urinal, or similar room, lavatory, locker, coat room, kitchen, boiler room, or rooms of similar use in which such air might be contaminated by smoke, gases, or dust which might be noxious, dangerous, or detrimental to health shall be recirculated at any time; except that air exhausted from locker and coat rooms or kitchens may be recirculated when unoccupied.
Municipal Code of Chicago § 18-28-403.1.1 Air reduction to actual load.
18-28-403.1.1 Air reduction to actual load.
For Variable Air Volume (VAV) systems, the amount of air delivered to any given space shall be allowed to be reduced to track the load in the space provided that the minimum amount of air delivered to the space is not less than 1/3 of the code required air supply.
Municipal Code of Chicago § 18-28-403.1.2 Demand ventilation.
18-28-403.1.2 Demand ventilation.
The amount of outside air delivered by a mechanical supply system may be reduced during operation below the quantities listed in Table 18-28-403.3 if the system is capable of measuring and maintaining CO2 levels in occupied spaces no greater than 1,000 ppm. The system capacity shall be greater than or equal to the ordinance requirements.
Municipal Code of Chicago § 18-28-403.1.3 Systems with water economizers.
18-28-403.1.3 Systems with water economizers.
If a system is equipped with a water economizer in accordance with the Chicago Energy Conservation Code, the amount of outside air delivered by the mechanical air handling system shall be no less than 1/3 of the code-required supply air. The area of the outside air intake shall be sized so that at least 1/3 of the code-required supply air can be taken from outdoors at velocities not in excess of 1,000 feet per minute (304.8 mpm) through the free area. The remaining air may be supplied by a recirculating air system if the system is equipped with devices to control temperature and dust content. The total quantity of air delivered to the space shall be 100 percent of the code-required air.
(Amend Coun. J. 9-14-21, p. 35949, Art. IV, § 3)
Municipal Code of Chicago § 18-28-403.2 Structural requirements of a mechanical system.
18-28-403.2 Structural requirements of a mechanical system.
Any system which conveys ventilation air shall be designed and installed in accordance with Article 6, Duct Systems.
Municipal Code of Chicago § 18-28-403.3 Ventilation requirements.
18-28-403.3 Ventilation requirements.
See Table 18-28-403.3, Ventilating Requirements.
Table 18-28-403.3
Ventilating Requirements*
For a printer-friendly PDF version of Table 18-28-403.3, please click here.
* S = Mechanical Supply; E = Mechanical Exhaust From Room; RO = Relief Opening; NR = No Requirement; NV = Natural Ventilation; Vent opening = percentage of floor area.
Room Purpose | Vent Opening Percent of Floor Area | Mechanical Ventil. CFM/SF | Remarks
Less Than | Not Less Than | S, Supply | E, Room Exhaust
Room Purpose | Vent Opening Percent of Floor Area | Mechanical Ventil. CFM/SF | Remarks
Less Than | Not Less Than | S, Supply | E, Room Exhaust
Correctional
Cell rooms | | 4 | 0 | 0 |
4 | | 1.2 | 1.2 |
Dry Cleaners/Laundries
Dry Cleaning | | 4 | 0 | 4 | See 18-28-403.3.3.
4 | | 1.5 | 4
Laundries (Residential for less than 30 units) | | 4 | 0 | 0 |
4 | | 0 | 1
Laundries serving general public | | | 1.5 | 1.5 | See 18-28-403.3.3.
Linen Rooms | | | 0.5 | 0.5 |
Education
Music Rooms | | 4 | 0 | 0 |
4 | | 1.5 | 0.75
Class Rooms/Auditoriums | | 4 | 0 | 0 |
4 | | 1.5 | 0.75
Cooking Rooms for Instruction only | | 4 | 0 | 1.5 |
4 | | 1.0 | 1.5
Libraries/Reading Rooms | | 4 | 0 | 0 |
4 | | 1.2 | 0.6
Food and Beverage Service
Cafeterias/Food Courts | | 4 | 0 | 0 |
4 | | 1.5 | 2.0
Public Dining Rooms - no cooking equipment | | 4 | 0 | 0 |
4 | | 1.5 | 1.5
Public Dining Rooms - with cooking equipment | | 4 | 0 | 2 |
4 | | 1.5 | 2
Grills | | 1 | 0 | 2 |
1 | | 1.5 | 2
Kitchen, public | | 3 | 0 | 4 | See Note 5.
3 | | 1.2 | 4
Lounges/Bars | | 4 | 0 | 0 |
4 | | 1.0 | 1.5
Health Care
Anesthesia Storage Rooms | | | 1.2 | 1.2 | See Note 5.
Autopsy Rooms | | | 1.5 | 3.0 | See Note 5.
Doctor's - Dentist exam rooms | | 4 | 0 | 0 |
4 | | 0.6 | 0.3
Delivery Rooms/Birthing Rooms | | | 2.0 | 1.0 |
Intensive Care | | | 2.0 | 1.0 | No recirculation within room.
Morgues | | | 1.5 | 3.0 | See Note 5.
Nurseries | | | 2.0 | 1.0 |
Operating Rooms | | | 2.0 | 1.0 | No recirculation within room.
Patient Rooms | | 4 | 0 | 0 | May exhaust through toilet room.
4 | | 0.3 | 0.3
Physiotherapy | | 4 | 0 | 0 |
4 | | 0.6 | 0.3
Recovery Rooms | | | 1.0 | 1.0 | No recirculation within room.
Sterilizing Equipment Rooms | | | 1.6 | 1.6 | No recirculation within room. See Note 5.
Treatment Rooms | | | 0.6 | 0.3 |
X-Ray operator's rooms | | | 0.6 | 0.3 |
Hotels, Motels and Dormitories
Banquet Halls/Assembly Pre-function | | | 2.0 | 1.5 |
Hotels (Lobby) | | 4 | 0 | 0 |
4 | | 1.0 | NR
Sleeping Rooms | | 4 | 0 | 0 | See Chapter 14B-12; may exhaust through toilet room.
4 | | 0.3 | 0.3
Toilet Rooms / Bathrooms – Private | | | | | See Note 6.
Foyers except the above | | | 0 | 0 |
Sleeping Rooms (Dormitories) | | 4 | NV | NV | See Chapter 14B-12.
Offices
Lunch Rooms - no cooking | | 4 | 0 | 0 |
4 | | 1.5 | 1.5
Offices and computer rooms | | 4 | 0 | 0 |
4 | | 0.6 | 0.3
Entrance lobby | | 4 | 0 | 0 |
4 | | 1.0 | NR
Private Dwellings (Single and Multiple)
Living Quarters | | | NV | NV | See Chapter 14B-12.
Living Quarters (Kitchen) | | 4 | 0 | 0 | See Note 7.
4 | | 0 | 1.5
Toilet Rooms / Bathrooms – Private | | | | | See Note 6.
Multi-Purpose Rooms | NR | NR | 0.3 | 0.3 or R.O. |
Public Spaces
Corridors | | | NR | NR |
Dressing Rooms | | 4 | 0 | 0 |
4 | | 1.0 | 1.2
Janitor's Closet | | | 0 | 2.0 | See Note 5.
Locker Rooms | | 4 | 0 | 0 | See Note 5.
4 | | 0.3 | 1.2
Pedestrian Passageways (below grade) | | | 1.5 | 1.0 |
Pedestrian Passageways (above grade) | | 4 | 0 | 0 |
4 | | 1.5 | 1.0
Shower Rooms | | 4 | 0 | 0 |
Smoking Rooms | | 4 | 0 | 0 | See Note 5.
4 | | 1.0 | 1.5
Toilet Rooms | | 4 | 0 | 0 | See Note 5.
4 | | 0 | 2.0
Waiting Rooms | | 4 | 0 | 0 |
4 | | 1.0 | 1.0
Retail Stores
Malls | | 4 | 0 | 0 |
4 | | 1.0 | 1.0
Retail Stores | | 4 | 0 | 0 |
4 | | 1.0 | 1.0
Specialty Shops
Auto and vehicle washing (attended) | | | 1.0 | 1.0 | See Note 5.
Auto repair shops | | | 1.0 | 1.0 | See Note 5.
Photo materials and engraving | | 4 | 0 | 0 | See 18-28-403.3.3.
4 | | 1.0 | 1.0
Beauty Parlors/Barber Shops | | 4 | 0 | 0 | See Note 5.
4 | | 1.2 | 1.2
Theaters
Auditoriums (including stage) | | 4 | 0 | 0 |
4 | | 2.0 | 1.5
Concert Halls | | 4 | 0 | 0 |
4 | | 2.0 | 1.5 |
Foyers in Theaters | | | 1.0 | 1.0 |
4 | | 2.0 | 1.0
Studios – motion picture, radio, TV | | | 1.5 | 0.75 | Or RO.
Theatrical Community Centers | | 4 | 0 | 0 |
4 | | 1.5 | 0.75
Workrooms
Workshops not otherwise classified | | 4 | 0 | 0 | See 18-28-403.3.3.
4 | | 1.2 | 1.2
Wood working shop | 0 | 4 | 0 | 0 | See Article 5 - Makeup air is required when direct exhaust > 5, 000 CFM.
4 | | 1.2 | 1.2
Spray Finishing | | 4 | | | See Article 5 - Makeup air is required when direct exhaust > 5, 000 CFM.
4 | | 1.5 | 1.2
Spray Booths | | 4 | | | See Article 5 - Makeup air is required when direct exhaust > 5, 000 CFM.
4 | | 1.5 | 1.5
Bank Vaults Attended | | | 0.6 | 0.3 |
Battery Charging - Dry Cell Batteries | | | NR | 0.5 | 3 or more batteries.
- Other Batteries | | | NR | 1.0
Sports and Amusement
Bowling Alleys (seating areas) | | 4 | 0 | 0 |
4 | | 1.7 | 0.85
Ball Rooms | | 4 | 0 | 0 |
4 | | 2.0 | 1.5
Cabarets | | 4 | 0 | 0 |
4 | | 2.0 | 1.5
Dance Halls/Discos | | 4 | 0 | 0 |
4 | | 2.0 | 1.5
Game Rooms/Arcades | | 4 | 0 | 0 |
4 | | 1.6 | 1.6
Gymnasiums | | 4 | 0 | 0 | Or RO.
4 | | 2.0 | 1.5
Natatoriums (deck and seating) | | 4 | 0 | 0 |
4 | | 2.0 | 1.5
Recreation Rooms | | 4 | 0 | 0 |
4 | | 2.0 | 1.5
Skating Rinks, Ice Arenas | | 4 | 0 | 0 |
4 | | 1.5 | 1.5
Skating Rinks, Roller | | 4 | 0 | 0 |
4 | | 2.0 | 1.5
Storage
Storage inactive | | | 0 | 0 |
Storage active | | | 0.5 | 0.5 |
Storage cold (no permanent occupancy) | | | 0 | 0 |
Vault, Storage | | | NR | NR |
Laboratories
Laboratories | | 5 | 0 | 0 | See 18-28-403.3.3.
5 | | 1.2 | 1.2
Animal Rooms | | | 0 | 1.5 |
Religious
Auditoriums for worship/Chapels | | 4 | 0 | 0 | Or RO.
4 | | 1.5 | 0.75
Special Use
Convention Halls | | 4 | 0 | 0 |
4 | | 2.0 | 1.5
Council Chambers | | 4 | 0 | 0 |
4 | | 2.0 | 1.5
Court Rooms | | 4 | 0 | 0 |
4 | | 2.0 | 1.5
Exhibition Rooms | | | 1.5 | 0.75 | Or RO.
Fraternal Rooms | | | 1.5 | 0.75 | Or RO.
Lodge Halls | | | 1.5 | 0.75 | Or RO.
Museums | | | 0.6 | NR | Or RO.
Garages/Parking Structures | See Miscellaneous
Garages, 6 or more cars | | | 0.75 | 1.0 |
| | RO | 1.0 |
Private Garages (less than 6 cars) | | | RO | RO | 1.0 sf of opening per car.
Garages in or attached to Hospitals | | | 0.75 | 1.0 | Exhaust duct, 14 gauge.
| | RO | 1.0
Note 1. [Reserved.]
Note 2. [Reserved.]
Note 3. [Reserved.]
Note 4. Corridor make-up air system for residential building over 55 feet in height shall be sized to equal the total of toilet, kitchen and dryer air exhaust requirements.
Note 5. There shall be no recirculation permitted from these spaces.
Note 6. For each private toilet room or bathroom: 20 CFM when the exhaust system is designed to operate continuously when the associated living quarters are occupied; 50 CFM when the exhaust system is designed to operate intermittently. For intermittent operation, either an automatic control or ready access to a manual control shall be provided within the room.
Note 7. For each residential kitchen: 50 CFM when the kitchen is enclosed and the exhaust system is designed to operate continuously when the associated living quarters are occupied; 100 CFM vented range hood or 300 CFM mechanical exhaust (including downdraft) when the kitchen is unenclosed or the exhaust system is designed to operate intermittently. For intermittent operation, either an automatic control or ready access to a manual control shall be provided within the room.
(Amend Coun. J. 9-14-16, p. 31143, § 8; Amend Coun. J. 3-29-17, p. 45477, § 12; Amend Coun. J. 4-10-19, p. 100029, Art. XII, § 5; Amend Coun. J. 9-14-21, p. 35949, Art. IV, § 4; Amend Coun. J. 9-21-22, p. 52080, Art. II, § 8)
Municipal Code of Chicago § 18-28-403.3.1 .
18-28-403.3.1.
If a room or department in any factory is to process, brew, or mill food or beverages, and a large floor area is occupied by permanently installed, closed tanks, vats or food processing equipment (thus reducing occupiable floor space), the minimum ventilating requirements specified in Table 18-28-403.3 shall be adjusted and determined to conform to the following requirements.
1. Rooms in which the total area of the ventilating opening is 4 percent or more than the "employees" net work floor area shall conform to the requirements for natural ventilation.
2. Rooms which have no ventilation opening or in which the total area of the ventilation opening is less than four percent of the "employees" net work floor area shall provide supply and exhaust of 1.2 cfm per square foot of net work floor area.
Municipal Code of Chicago § 18-28-403.3.2 Refrigerated rooms.
18-28-403.3.2 Refrigerated rooms.
If a refrigerated room or area is not used for human occupancy, no ventilation requirements shall apply. If a refrigerated room or area is used for human occupancy, supply and exhaust of 0.6 cfm per square foot shall be provided in the refrigerated room or area.
Exceptions:
1. The table of minimum ventilation requirements does not apply to any mechanically refrigerated room or area necessarily used and required to age food or beverages.
2. The table of minimum ventilation requirements does not apply to the storage and preservation of meat, food and beverage products.
Municipal Code of Chicago § 18-28-403.3.3 Dangerous or noxious contaminants.
18-28-403.3.3 Dangerous or noxious contaminants.
If the nature of any work being done in a room or area is of such a character that dangerous or noxious dust, fumes, mists, gases, odors or other contaminants harmful to workers or occupants may get discharged, the ventilating requirements found in Table 18-28-403.3 shall be supplemented by using a local mechanical exhaust to remove the emission at its source, to prevent the escape of contaminants to the occupied space, and to discharge the mechanical exhaust to the outside atmosphere. Such mechanical exhaust shall be equipped with suitable means for the collection and removal of the contaminates. See Article 5, Exhaust Systems.
Municipal Code of Chicago § 18-28-403.3.4 Total air supply.
18-28-403.3.4 Total air supply.
The total air supplied from the outside atmosphere shall be equivalent to, or greater than the total air volume removed by the general and local exhaust systems. See also Article 5, Exhaust Systems.
Municipal Code of Chicago § 18-28-403.3.5 Air filter requirements.
18-28-403.3.5 Air filter requirements.
Ventilating systems that serve anaesthetizing rooms, intensive care rooms, patient rooms, operating rooms, nurseries, delivery rooms and similar health care rooms shall have at least 2 banks of air filters and shall meet the following requirements:
1. Filter Bank No. 1 shall be installed in the suction side of the supply fan and shall have a minimum air cleaning efficiency rating of 30 percent.
2. Filter Bank No. 2 shall be installed on the pressure side of the supply fan and shall have a minimum air cleaning efficiency rating of 90 percent.
3. All air cleaning efficiencies shall be based on the National Bureau of Standards Dust Spot Test Method and Atmospheric Dust.
Municipal Code of Chicago § 18-28-403.3.6 Pedestrian passage way.
18-28-403.3.6 Pedestrian passage way.
The velocity of air movement due to ventilation at any cross section of a pedestrian passage way shall not exceed 60 feet per minute.
Municipal Code of Chicago § 18-28-403.3.7 Reserved. Editor's note – Coun. J. 9-14-21, p. 35949, Art. IV, § 5, repealed § 18-28-401.3.7, which pertained to air-to-air heat recovery and air energy transfer equipment.
Municipal Code of Chicago § 18-28-403.3.7.1 Reserved. Editor's note – Coun. J. 9-14-21, p. 35949, Art. IV, § 5, repealed § 18-28-401.3.7.1, which pertained to materials and media.
Municipal Code of Chicago § 18-28-403.3.7.2 Reserved. Editor's note – Coun. J. 9-14-21, p. 35949, Art. IV, § 5, repealed § 18-28-403.3.7.2, which pertained to direct exposure of heat transfer media.
Municipal Code of Chicago § 18-28-403.3.8 Outside air requirements.
18-28-403.3.8 Outside air requirements.
If a mechanical exhaust system is required, the outside air needed to replace the air exhausted from each room shall be obtained from ventilation openings in that room or from a mechanical ventilating supply system installed for that room.
Exceptions:
1. In foyers, living quarters, offices, rest rooms, lobbies, locker rooms, medicine rooms and picture galleries, ventilation also may be obtained from a mechanical ventilating supply system serving rooms adjacent to the designated room, either alone or in combination with the designated room, if the quantity of air supplied to the adjacent room is not less than that required for both the designated room and the adjacent rooms.
2. In public kitchens and serving pantries, ventilation air may be obtained through ventilation openings from dining rooms adjacent to designated rooms, if the area of the ventilation openings in the dining room is not less than 4 percent of the combined floor area of the dining room and the kitchen or serving pantry. Such ventilation comply with the following:
2.1 If the dining room is provided with a mechanical supply system of ventilation, air from the dining room can be taken through proper openings into the kitchen and exhausted from the kitchen. Such air shall be considered as exhaust from the dining room and as supply air into the kitchen.
2.2 A kitchen exhaust system need not be increased beyond the requirements for kitchen exhaust as indicated in Table 18-28-403.3.
2.3 If the amount of air exhausted from the dining room through the kitchen is not sufficient to provide exhaust as indicated in Table 18-28-403.3, additional exhaust shall be taken from the dining room area to make up such requirement, either by increasing exhaust from the kitchen or by installing a separate additional mechanical exhaust system.
3. In bath, toilet, and urinal rooms, check rooms, storage room, storage battery rooms, telephone switch rooms, and other rooms of similar character, ventilation may be obtained from ventilation openings in these rooms or from openings to uncontaminated rooms adjacent to the designated rooms if the following requirement is met:
3.1 The quantity of air supplied to the adjacent rooms is not less than the air exhausted through the designated rooms.
Municipal Code of Chicago § 18-28-403.4 Deliberately omitted.
Municipal Code of Chicago § 18-28-403.5 Deliberately omitted.
Municipal Code of Chicago § 18-28-403.6 Deliberately omitted.
Municipal Code of Chicago § 18-28-403.7 Deliberately omitted.
Municipal Code of Chicago § 18-28-403.8 Deliberately omitted.
Municipal Code of Chicago § 18-28-403.9 Exhaust through direct openings or ducts.
18-28-403.9 Exhaust through direct openings or ducts.
If a mechanical ventilating exhaust system is required in any room, air may be exhausted to corridors or uninhabited rooms through direct openings or horizontal ducts not to exceed 5 feet (1525 mm) in length if all of the following requirements are met:
1. The room being supplied does not contain dangerous or noxious fumes, odor or dust; and
2. Adequate relief openings for mechanical exhaust exist in such corridors or uninhabited rooms.
Municipal Code of Chicago § 18-28-403.10 Garages.
18-28-403.10 Garages.
For the purpose of all garage ventilation requirements found in Table 18-28-403.3, the following rules shall apply: If a building is used for active storage of cars only, relief openings may be located in walls, areaways or roofs. If the garage is capable of accommodating six cars or more and is used for active storage of cars only, the required air supply may be unheated.
(Amend Coun. J. 3-29-17, p. 45477, § 12)
Municipal Code of Chicago § 18-28-403.11 Multi-purpose rooms.
18-28-403.11 Multi-purpose rooms.
If a room is used for two or more purposes, each of which is subject to different ventilating requirements, and it is possible to determine the space which will be used for each purpose, then each such space may be considered as a separate room and ventilated in accordance with the table of ventilating requirements applicable to that room. If it is not possible to determine the space which will be used for each purpose, the most restrictive, applicable ventilating requirements shall apply to the entire room.
Municipal Code of Chicago § 18-28-403.12 Partitions.
18-28-403.12 Partitions.
If a partition stops at a distance of 2 feet or more below ceiling level, the partition shall not be considered to form an independent room; the space on both sides of the partition shall be considered to form one room. A grille with an opening of not less than 75 percent free area may be placed in the 2 feet space. Door height shall not be considered to be part of the partition.
Municipal Code of Chicago § 18-28-403.13 Public garages.
18-28-403.13 Public garages.
If a mechanical ventilating system is used in a public garage, the system shall not be required to operate continuously if the system is equipped with an approved detection device that operates automatically upon detection of a concentration of carbon monoxide of 50 parts per million (ppm). The minimum density of carbon monoxide detectors shall be one detector for every 5,000 square feet of garage floor area. If the general exhaust of a building is discharged into a mechanically-exhausted public garage, the garage exhaust system shall exhaust at least 100 percent of the ordinance required air.
Municipal Code of Chicago § 18-28-403.14 Compliance.
18-28-403.14 Compliance.
The applicant for any permit ventilation schedule in a form substantially similar to Table 18-28-403.14 shall be submitted with permit plans to demonstrate compliance with the Ventilation Article of this chapter.
Table 18-28-403.14
Ventilation
Room Description | Ordinance Requirements | Actual Provided | Remarks/ Room Function
Natural Light & Ventil. (SF) | Mechanical Ventil. (CFM) | Natural Light & Ventil. (SF) | Mechanical Ventil. (CFM)
Room No. | Room Name | Floor Area (Sf) | Glass Area | Vent Area | Supply Area | Exhaust Air from Room | Glass Area | Vent Area | Supply Air | Exhaust Air from Room
– | – | – | – | – | – | – | – | – | – | – | –
Municipal Code of Chicago § 18-28-403.15 Generator rooms.
18-28-403.15 Generator rooms.
A room containing a generator shall meet the air flow and combustion air requirements in the Chicago Electrical Code.
(Amend Coun. J. 9-14-21, p. 35949, Art. IV, § 6)
Municipal Code of Chicago § 18-28-404 Deliberately omitted.
Municipal Code of Chicago § 18-28-405 Deliberately omitted.
Municipal Code of Chicago § 18-28-406.1 General.
18-28-406.1 General.
Uninhabited spaces, such as crawl spaces and attics, shall be provided with natural ventilation openings as required by Chapter 12 of the Chicago Building Code 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 m 3 /s • m 2 ) of horizontal area and shall be automatically controlled to operate when the relative humidity in the space served exceeds 60 percent.
(Amend Coun. J. 9-14-21, p. 35949, Art. IV, § 7)
Source: City of Chicago, Municipal Code of Chicago (American Legal Publishing, codelibrary.amlegal.com)URL: https://codelibrary.amlegal.com/codes/chicago/latest/chicago_il/0-0-0-2694552Fetched: 10/24/2026