| EXCEPTIONS: | 1. 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. |
| 2. Alternate systems designed in accordance with ASHRAE Standard 62.1 Section 6.2, Ventilation Rate Procedure, shall be permitted. |
| EXCEPTION: | Where occupancy density is known and documented in the plans, the outside air rate may be based on the design occupant density. Under no circumstance shall the occupancies used result in outside air less than one-half that resulting from application of Table 403.3 estimated maximum occupancy rates. |
| Occupancy Classification | People Outdoor
Airflow Rate in
Breathing Zone cfm/Person |
Area Outdoor Airflow
Rate in Breathing
Zone Ra cfm/ft2a |
Default Occupant Density #/1000 ft2a | Exhaust Airflow Rate cfm/ft2 | ||
| Correctional facilities | ||||||
| Cells | ||||||
| without plumbing fixtures | 5 | 0.12 | 25 | -- | ||
| with plumbing fixtures | 5 | 0.12 | 25 | 1.0 | ||
| Dining halls (see food and beverage service) | -- | -- | -- | -- | ||
| Guard stations | 5 | 0.06 | 15 | -- | ||
| Day room | 5 | 0.06 | 30 | -- | ||
| Booking/waiting | 7.5 | 0.06 | 50 | -- | ||
| Dry cleaners, laundries | ||||||
| Coin-operated dry cleaner | 15 | -- | 20 | -- | ||
| Coin-operated laundries | 7.5 | 0.06 | 20 | -- | ||
| Commercial dry cleaner | 30 | -- | 30 | -- | ||
| Commercial laundry | 25 | -- | 10 | -- | ||
| Storage, pick up | 7.5 | 0.12 | 30 | -- | ||
| Education | ||||||
| Art classroom | 10 | 0.18 | 20 | 0.7 | ||
| Auditoriums | 5 | 0.06 | 150 | -- | ||
| Classrooms (ages 5-8) | 10 | 0.12 | 25 | -- | ||
| Classrooms (ages 9 plus) | 10 | 0.12 | 35 | -- | ||
| Computer lab | 10 | 0.12 | 25 | -- | ||
| Corridors (see public spaces) | -- | -- | -- | -- | ||
| Day care (through age 4) | 10 | 0.18 | 25 | -- | ||
| Lecture classroom | 7.5 | 0.06 | 65 | -- | ||
| Lecture hall (fixed seats) | 7.5 | 0.06 | 150 | -- | ||
| Locker/dressing room | -- | -- | -- | 0.25 | ||
| Media center | 10 | 0.12 | 25 | -- | ||
| Multiuse assembly | 7.5 | 0.06 | 100 | -- | ||
| Music/theater/dance | 10 | 0.06 | 35 | -- | ||
| Science laboratories | 10 | 0.18 | 25 | 1.0 | ||
| Smoking loungesb | 60 | -- | 70 | -- | ||
| Sports locker rooms | -- | -- | -- | 0.5 | ||
| Wood/metal shops | 10 | 0.18 | 20 | 0.5 | ||
| Food and beverage service | ||||||
| Bars, cocktail lounges | 7.5 | 0.18 | 100 | -- | ||
| Cafeteria, fast food | 7.5 | 0.18 | 100 | -- | ||
| Dining rooms | 7.5 | 0.18 | 70 | -- | ||
| Kitchens (cooking)b | -- | -- | -- | 0.7 | ||
| Hospitals, nursing and convalescent homes | ||||||
| Autopsy roomsb | -- | -- | -- | 0.5 | ||
| Medical procedure rooms | 15 | -- | 20 | |||
| Operating rooms | 30 | -- | 20 | |||
| Patient rooms | 25 | -- | 10 | |||
| Physical therapy | 15 | -- | 20 | |||
| Recovery and ICU | 15 | -- | 20 | |||
| Hotels, motels, resorts and dormitories | ||||||
| Multipurpose assembly | 5 | 0.06 | 120 | -- | ||
| Bathrooms/toilet -- private |
-- | -- | -- | 25/50f | ||
| Bedroom/living room | 5 | 0.06 | 10 | -- | ||
| Conference/meeting | 5 | 0.06 | 50 | -- | ||
| Dormitory sleeping areas | 5 | 0.06 | 20 | -- | ||
| Gambling casinos | 7.5 | 0.18 | 120 | -- | ||
| Kitchens | -- | -- | -- | 25/100f | ||
| Lobbies/prefunction | 7.5 | 0.06 | 30 | -- | ||
| Offices | ||||||
| Conference rooms | 5 | 0.06 | 50 | -- | ||
| Office spaces | 5 | 0.06 | 5 | -- | ||
| Reception areas | 60 | 0.06 | 30 | -- | ||
| Telephone/data entry | 5 | 0.06 | 60 | -- | ||
| Main entry lobbies | 5 | 0.06 | 10 | -- | ||
| Private dwellings, single and multiple | ||||||
| Garages, common for multiple unitsb | -- | -- | -- | 0.75 | ||
| Garages, separate for each dwellingb | -- | -- | -- | 100 cfm per car | ||
| Kitchensb | -- | 25/100f | ||||
| Living areasc | See Tables 403.8.5.1 and 403.8.5.2 | -- | Based on the number of bedrooms. First bedroom: 2; each additional bedroom, 1 | -- | ||
| Toilet rooms, bathrooms and laundry areasi | -- | 20/50f | ||||
| Public spaces | ||||||
| Corridors | -- | 0.06 | -- | -- | ||
| Elevator car | -- | -- | -- | 1.0 | ||
| Shower room (per shower head) | -- | -- | -- | 50/20f | ||
| Smoking loungesb | 60 | -- | 70 | -- | ||
| Toilet rooms - public | -- | -- | -- | 50/70e | ||
| Places of religious worship | 5 | 0.06 | 120 | -- | ||
| Courtrooms | 5 | 0.06 | 70 | -- | ||
| Legislative chambers | 5 | 0.06 | 50 | -- | ||
| Libraries | 5 | 0.12 | 10 | -- | ||
| Museums (children's) | 7.5 | 0.12 | 40 | -- | ||
| Museums/galleries | 7.5 | 0.06 | 40 | -- | ||
| Retail stores, sales floors and showroom floors | ||||||
| Sales (except as below) | 7.5 | 0.12 | 15 | -- | ||
| Dressing rooms | -- | -- | -- | 0.25 | ||
| Mall common areas | 7.5 | 0.06 | 40 | -- | ||
| Shipping and receiving | -- | 0.12 | -- | -- | ||
| Smoking loungesb | 60 | -- | 70 | -- | ||
| Storage rooms | -- | 0.12 | -- | -- | ||
| Warehouses (see storage) | -- | -- | -- | -- | ||
| Specialty shops | ||||||
| Automotive motor-fuel-dispensing stationsb | -- | -- | -- | 1.5 | ||
| Barber | 7.5 | 0.06 | 25 | 0.5 | ||
| Beauty and nail salonsb,h | 20 | 0.12 | 25 | 0.6 | ||
| Embalming roomb | -- | -- | -- | 2.0 | ||
| Pet shops (animal areas)b | 7.5 | 0.18 | 10 | 0.9 | ||
| Supermarkets | 7.5 | 0.06 | 8 | -- | ||
| Sports and amusement | ||||||
| Disco/dance floors | 20 | 0.06 | 100 | -- | ||
| Bowling alleys (seating areas) | 10 | 0.12 | 40 | -- | ||
| Game arcades | 7.5 | 0.18 | 20 | -- | ||
| Ice arenas, without combustion engines | -- | 0.30 | -- | 0.5 | ||
| Gym, stadium arena (play area) | -- | 0.30 | -- | -- | ||
| Spectator areas | 7.5 | 0.06 | 150 | -- | ||
| Swimming pools (pool and deck area) | -- | 0.48 | -- | -- | ||
| Health club/aerobics room | 20 | 0.06 | 40 | -- | ||
| Health club/weight room | 20 | 0.06 | 10 | -- | ||
| Storage | ||||||
| Repair garages, enclosed parking garageb,d | -- | -- | -- | 0.75 | ||
| Warehouses | -- | 0.06 | -- | -- | ||
| Theaters | ||||||
| Auditoriums (see education) | -- | -- | ||||
| Lobbies | 5 | 0.06 | 150 | -- | ||
| Stages, studios | 10 | 0.06 | 70 | -- | ||
| Ticket booths | 5 | 0.06 | 60 | -- | ||
| Transportation | ||||||
| Platforms | 7.5 | 0.06 | 100 | -- | ||
| Transportation waiting | 7.5 | 0.06 | 100 | -- | ||
| Workrooms | ||||||
| Bank vaults/safe deposit | 5 | 0.06 | 5 | -- | ||
| Darkrooms | -- | -- | -- | 1.0 | ||
| Copy, printing rooms | 5 | 0.06 | 4 | 0.5 | ||
| Meat processingc | 15 | -- | 10 | -- | ||
| Pharmacy (prep area) | 5 | 0.18 | 10 | -- | ||
| Photo studios | 5 | 0.12 | 10 | -- | ||
| Computer (without printing) | 5 | 0.06 | 4 | -- | ||
| For SI: | 1 cubic foot per minute = 0.0004719 m3/s, 1 ton = 908 kg, 1 cubic foot per minutes per square foot = 0.00508 m3/(s•m2), °C = [(°F) -32]/1.8, 1 square foot - 0.0929 m2. |
| a. | Based upon net occupiable floor area. |
| b. | Mechanical exhaust required and the recirculation of air from such spaces is prohibited (see Section 403.2.1, Item 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. | Rates are per water closet or urinal. The higher rate shall be provided where periods of heavy use are expected to occur, such as toilets in theaters, schools and sports facilities. The lower rate shall be permitted where periods of heavy use are not expected. |
| f. | Rates are per room unless otherwise indicated. The higher rate shall be provided where the exhaust system is designed to operate intermittently. The lower rate shall be permitted where the exhaust system is designed to operate continuously during normal hours of use. |
| g. | Reserved. |
| h. | For nail salons, the required exhaust shall include ventilation tables or other systems that capture the contaminants and odors at their source and are capable of exhausting a minimum of 50 cfm per station. |
| i. | A laundry area within a kitchen or bathroom is not required to have source specific exhaust. Where there are doors that separate the laundry area from the kitchen or bathroom the door shall be louvered. |
| Floor Area | Bedrooms1 | ||||||||||
| (ft2) | 0-1 | 2-3 | 4-5 | 6-7 | >7 | ||||||
| <1500 | 30 | 45 | 60 | 75 | 90 | ||||||
| 1501 - 3000 | 45 | 60 | 75 | 90 | 105 | ||||||
| 3001 - 4500 | 60 | 75 | 90 | 105 | 120 | ||||||
| 4501 - 6000 | 75 | 90 | 105 | 120 | 135 | ||||||
| 6001 - 7500 | 90 | 105 | 120 | 135 | 150 | ||||||
| >7500 | 105 | 120 | 135 | 150 | 165 | ||||||
| 1Ventilation rates in table are minimum outdoor airflow rates measured in cfm. |
| EXCEPTION: | Where a range hood or down draft exhaust fan is used for source specific exhaust for a kitchen, the device is not required to be rated per these standards. |
| EXCEPTIONS: | 1. An exhaust airflow rating at a pressure of 0.25 in. w.g. may be used, provided the duct sizing meets the prescriptive requirements of Table 403.8.4.2. |
| 2. Where a range hood or down draft exhaust fan is used to satisfy the source specific ventilation requirements for kitchens, the range hood or down draft exhaust shall not be less than 100 cfm at 0.10 in. w.g. |
| Fan Tested cfm at 0.25 inches w.g. | Minimum Flex Diameter | Maximum Length in Feet |
Minimum Smooth Diameter | Maximum Length in Feet | Maximum Elbows1 | ||||
| 50 | 4 inches | 25 | 4 inches | 70 | 3 | ||||
| 50 | 5 inches | 90 | 5 inches | 100 | 3 | ||||
| 50 | 6 inches | No Limit | 6 inches | No Limit | 3 | ||||
| 80 | 4 inches2 | NA | 4 inches | 20 | 3 | ||||
| 80 | 5 inches | 15 | 5 inches | 100 | 3 | ||||
| 80 | 6 inches | 90 | 6 inches | No Limit | 3 | ||||
| 100 | 5 inches2 | NA | 5 inches | 50 | 3 | ||||
| 100 | 6 inches | 45 | 6 inches | No Limit | 3 | ||||
| 125 | 6 inches | 15 | 6 inches | No Limit | 3 | ||||
| 125 | 7 inches | 70 | 7 inches | No Limit | 3 | ||||
| 1. | For each additional elbow, subtract 10 feet from length. |
| 2. | Flex ducts of this diameter are not permitted with fans of this size. |
| EXCEPTION: | Intermittently operating ventilation systems: The mechanical system shall have controls for intermittent operation per Section 403.8.2 and shall supply at least the volume of outdoor air required for intermittent operation based on the combination of its delivered capacity (from Table 403.3 or Table 403.8.1), its ventilation effectiveness (from Table 403.8.5.1) and its daily fractional operation time (from Table 403.8.5.1) using the formula: |
| Qf = Qr/(&egr;f) | ||
| Where: | ||
| Qf | = | outdoor air flow rate |
| Qr | = | ventilation air requirement (from Table 403.3 or 403.8.1) |
| &egr; | = | ventilation effectiveness (from Table 403.8.5.1) |
| f | = | fractional operation time (from Table 403.8.5.1) |
| Daily Fractional Operation Time, f | Ventilation Effectiveness, &egr; | |
| f ≤ 35% | 0.33 | |
| 35% ≤ f < 60% | 0.50 | |
| 60% ≤ f < 80% | 0.75 | |
| 80% ≤ f | 1.0 | |
| EXCEPTION: | Outdoor air ducts at heat or energy ventilation systems are not required to have motorized dampers. |
| EXCEPTION: | The outdoor air duct for supply fan systems and heat or energy recovery systems may be prescriptively sized per Table 403.8.5.2 for dedicated outdoor air ducts upstream of the supply fan. Supply fans shall have the capacity to provide the amount of outdoor air required by Section 403.8.5.1 at 0.40 in. w.g. as per HVI 916 (April 1995). When prescriptively sized the system shall be tested and balanced using a flow hood, flow-grid, or other airflow measurement device. |
| Supply Fan Tested cfm at 0.40" w.g. | ||||
| Specified Volume from Table 408.1 | Minimum Smooth Duct Diameter | Minimum Flexible Duct Diameter | ||
| 50 - 90 cfm | 4 inch | 5 inch | ||
| 90 - 150 cfm | 5 inch | 6 inch | ||
| 150 - 250 cfm | 6 inch | 7 inch | ||
| 250 - 400 cfm | 7 inch | 8 inch | ||
| EXCEPTION: | An airflow rating at a pressure of 0.25 in. w.g. may be used, provided the duct sizing meets the prescriptive requirements of Table 403.8.5.2. |