Page 65 - 2018_IMC

EXHAUST SYSTEMS

are processed or handled shall be ventilated at a rate of not vehicles shall be provided with an approved exhaust venti-
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less than 1 cfm/ft [0.00508 m /(s • m )] of solid floor area. lation system in accordance with this code and Chapter 6
Ventilation shall be accomplished by exhaust fans that intake of NFPA 2.
at floor levels and discharge to a safe location outside the [F] 502.16.2 Exhaust ventilation system. Repair garages
structure. Noncontaminated intake air shall be introduced in used for the repair of compressed natural gas, liquefied
such a manner that all portions of solid floor areas are pro- natural gas or other lighter-than-air motor fuel, other than
vided with continuous uniformly distributed air movement. hydrogen, shall be provided with an approved mechanical
502.13 Public garages. Mechanical exhaust systems for pub- exhaust ventilation system. The mechanical exhaust venti-
lic garages, as required in Chapter 4, shall operate continu- lation system shall be in accordance with this code and
ously or in accordance with Section 404. Sections 502.16.2.1 and 502.16.2.2.
502.14 Motor vehicle operation. In areas where motor vehi- Exception: Where approved, natural ventilation shall
cles operate, mechanical ventilation shall be provided in be an alternative to mechanical exhaust ventilation.
accordance with Section 403. Additionally, areas in which [F] 502.16.2.1 Design. For indoor locations, air supply
stationary motor vehicles are operated shall be provided with inlets and exhaust outlets for mechanical ventilation
a source capture system that connects directly to the motor shall be arranged to provide uniformly distributed air
vehicle exhaust systems. Such system shall be engineered by movement with inlets uniformly arranged on walls near
a registered design professional or shall be factory-built floor level and outlets located at the high point of the
equipment designed and sized for the purpose. room in walls or the roof.
Exceptions: Failure of the exhaust ventilation system shall cause

1. This section shall not apply where the motor vehi- the fueling system to shut down.
cles being operated or repaired are electrically pow- The exhaust ventilation rate shall be not less than 1
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ered. cubic foot per minute (0.03 m /min) per 12 cubic feet
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2. This section shall not apply to one- and two-family (0.34 m ) of room volume.
dwellings. [F] 502.16.2.2 Operation. The mechanical exhaust
3. This section shall not apply to motor vehicle service ventilation system shall operate continuously.
areas where engines are operated inside the building Exceptions:
only for the duration necessary to move the motor 1. Mechanical exhaust ventilation systems that
vehicles in and out of the building.
are interlocked with a gas detection system
[F] 502.15 Repair garages. Where Class I liquids or LP-gas designed in accordance with the International
are stored or used within a building having a basement or pit Fire Code.
wherein flammable vapors could accumulate, the basement or 2. Mechanical exhaust ventilation systems in
pit shall be provided with ventilation designed to prevent the garages that are used only for the repair of
accumulation of flammable vapors therein. vehicles fueled by liquid fuels or odorized
[F] 502.16 Repair garages for vehicles fueled by lighter- gases, such as compressed natural gas, where
than-air fuels. Repair garages used for the conversion and the exhaust ventilation system is electrically
repair of vehicles that use compressed natural gas, liquefied interlocked with the lighting circuit.
natural gas, hydrogen or other lighter-than-air motor fuels 502.17 Tire rebuilding or recapping. Each room where rub-
shall be provided with an approved mechanical exhaust ven- ber cement is used or mixed, or where flammable or combus-
tilation system. The mechanical exhaust ventilation system tible solvents are applied, shall be ventilated in accordance
shall be in accordance with Section 502.16.1 or 502.16.2 as with the applicable provisions of NFPA 91.
applicable.
Exceptions: 502.17.1 Buffing machines. Each buffing machine shall
be connected to a dust-collecting system that prevents the
1. Repair garages where work is not performed on the accumulation of the dust produced by the buffing process.
fuel system and is limited to exchange of parts and
502.18 Specific rooms. Specific rooms, including bath-
maintenance not requiring open flame or welding on
the compressed natural gas, liquefied natural gas, rooms, locker rooms, smoking lounges and toilet rooms, shall
hydrogen or other lighter-than-air-fueled motor be exhausted in accordance with the ventilation requirements
vehicle. of Chapter 4.
2. Repair garages for hydrogen-fueled vehicles where 502.19 Indoor firing ranges. Ventilation shall be provided
work is not performed on the hydrogen storage tank in an approved manner in areas utilized as indoor firing
and is limited to the exchange of parts and mainte- ranges. Ventilation shall be designed to protect employees
nance not requiring open flame or welding on the and the public in accordance with DOL 29 CFR 1910.1025
hydrogen-fueled vehicle. During the work, the entire where applicable.
hydrogen fuel system shall contain a quantity of 502.20 Manicure and pedicure stations. Manicure and ped-
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hydrogen that is less than 200 cubic feet (5.6 m ). icure stations shall be provided with an exhaust system in
[F] 502.16.1 Repair garages for hydrogen-fueled vehi- accordance with Table 403.3.1.1, Note h. Manicure tables
cles. Repair garages used for the repair of hydrogen-fueled and pedicure stations not provided with factory-installed

48 2018 INTERNATIONAL MECHANICAL CODE 
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