CHAPTER 18-28
MECHANICAL SYSTEMS*
* Editor's note – Chapter 18-28, Mechanical Refrigeration Systems, was added by Coun. J. 7-9-03, p. 3609, § 2, and was effective 90 days after its passage and publication (October 27, 2003). Coun. J. 11-21-17, p. 61913, § 7 amended the title of Chapter 18-28.
Article I.  Administration
18-28-101   General.
18-28-101.1   Deliberately omitted.
18-28-101.2   Scope.
18-28-101.2.1   Appendices.
18-28-101.3   Intent.
18-28-101.4   Deliberately omitted.
18-28-102   Applicability.
18-28-102.1   General.
18-28-102.2   Existing installations.
18-28-102.3   Maintenance.
18-28-102.4   Additions, alterations or repairs.
18-28-102.5   Change in occupancy.
18-28-102.6   Deliberately omitted.
18-28-102.7   Moved buildings.
18-28-102.8   Referenced chapters and standards.
18-28-102.9   Requirements not covered by this chapter.
18-28-103   Deliberately omitted.
18-28-104   Deliberately omitted.
18-28-105   Testing.
18-28-105.1   Deliberately omitted.
18-28-105.2   Deliberately omitted.
18-28-105.3   Required testing.
18-28-106   Permits.
18-28-106.1   When required.
18-28-106.1.1   Work without a permit.
18-28-107   Deliberately omitted.
18-28-108   Deliberately omitted.
18-28-109   Deliberately omitted.
Article II.  Definitions
18-28-201   General.
18-28-201.1   Scope.
18-28-201.2   Interchangeability.
18-28-201.3   Terms defined in other codes.
18-28-201.4   Terms not defined.
18-28-202   General definitions.
Article III.  General Regulations
18-28-301   General.
18-28-301.1   Scope.
18-28-301.2   Energy utilization.
18-28-301.3   Listed and labeled.
18-28-301.4   Deliberately omitted.
18-28-301.5   Label information.
18-28-301.6   Conflicts.
18-28-301.7   Electrical.
18-28-301.8   Plumbing connections.
18-28-301.9   Fuel types.
18-28-301.10   Vibration isolation.
18-28-301.11   Repair.
18-28-301.12   Wind resistance.
18-28-301.13   Flood hazard.
18-28-301.14   Deliberately omitted.
18-28-302   Protection of structure.
18-28-302.1   Penetrations of floor/ceiling assemblies and fire-resistance-rated assemblies.
18-28-303   Equipment and appliance location.
18-28-303.1   General.
18-28-303.2   Hazardous locations.
18-28-304   Deliberately omitted.
18-28-305   Piping support.
18-28-305.1   General.
18-28-305.2   Materials.
18-28-305.3   Structural attachment.
18-28-305.4   Interval of support.
18-28-305.5   Sway bracing.
18-28-306   Access and service space.
18-28-306.1   Refer to Article.
18-28-306.2   Deliberately omitted.
18-28-306.3   Deliberately omitted.
18-28-306.4   Deliberately omitted.
18-28-306.5   Equipment and appliances on roofs or elevated structures.
18-28-306.6   Sloped roofs.
18-28-307   Condensate disposal.
18-28-307.1   Fuel-burning appliances.
18-28-307.2   Evaporators and cooling coils.
18-28-307.2.1   Condensate disposal.
18-28-307.2.1.1   French drain.
18-28-307.2.2   Drain pipe materials and sizes.
18-28-307.2.3   Auxiliary drain pans.
18-28-307.2.4   Secondary drain system.
18-28-307.2.5   Traps.
18-28-308   Clearance reduction.
18-28-308.1   Scope.
18-28-308.2   Listed appliances and equipment.
18-28-308.3   Protective assembly construction and installation.
18-28-308.4   Allowable reduction.
18-28-308.5   Labeled assemblies.
18-28-308.6   Reduction table.
18-28-308.7   Solid fuel-burning appliances.
18-28-308.8   Masonry chimneys.
18-28-308.9   Chimney connector pass-throughs.
18-28-308.10   Masonry fireplaces.
18-28-308.11   Kitchen exhaust ducts.
18-28-309   Deliberately omitted.
18-28-310   Deliberately omitted.
18-28-311   Deliberately omitted.
18-28-312   Deliberately omitted.
Article IV.  Ventilation
18-28-401   General.
18-28-401.1   Scope.
18-28-401.2   Ventilation required.
18-28-401.3   When required.
18-28-401.4   Method of producing ventilation.
18-28-401.5   Ventilation openings.
18-28-401.5.1   Area of the openings.
18-28-401.5.1.1   Windows.
18-28-401.5.1.2   Skylights.
18-28-401.5.1.3   Transoms.
18-28-401.5.1.4   Auxiliary ventilating openings.
18-28-401.5.1.5   Relief openings.
18-28-401.5.1.6   Air quantities.
18-28-401.5.1.7   Damper.
18-28-401.5.2   Opening location.
18-28-401.5.3   Points of exhaust discharge.
18-28-401.6   Outdoor air opening and protection.
18-28-401.7   Additional ventilation.
18-28-402   Natural ventilation.
18-28-402.1   Natural ventilation.
18-28-403   Mechanical ventilation.
18-28-403.1   Source of air supply.
18-28-403.1.1   Air reduction to actual load.
18-28-403.1.2   Demand ventilation.
18-28-403.1.3   Systems with water economizers.
18-28-403.2   Structural requirements of a mechanical system.
18-28-403.3   Ventilation requirements.
18-28-403.3.1   [No caption.]
18-28-403.3.2   Refrigerated rooms.
18-28-403.3.3   Dangerous or noxious contaminants.
18-28-403.3.4   Total air supply.
18-28-403.3.5   Air filter requirements.
18-28-403.3.6   Pedestrian passage way.
18-28-403.3.7   Air-to-air heat recovery and air energy transfer equipment.
18-28-403.3.7.1   Materials and media.
18-28-403.3.7.2   Direct exposure of heat transfer media.
18-28-403.3.8   Outside air requirements.
18-28-403.4   Deliberately omitted.
18-28-403.5   Deliberately omitted.
18-28-403.6   Deliberately omitted.
18-28-403.7   Deliberately omitted.
18-28-403.8   Deliberately omitted.
18-28-403.9   Exhaust through direct openings or ducts.
18-28-403.10   Garages.
18-28-403.11   Multi-purpose rooms.
18-28-403.12   Partitions.
18-28-403.13   Public garages.
18-28-403.14   Compliance.
18-28-403.15   Miscellaneous spaces.
18-28-404   Deliberately omitted.
18-28-405   Deliberately omitted.
18-28-406   Deliberately omitted.
Article V.  Exhaust Systems
18-28-501   General.
18-28-501.1   Scope.
18-28-501.2   Independent system required.
18-28-501.3   Outdoor discharge.
18-28-501.4   Pressure equalization.
18-28-501.5   Ducts.
18-28-502   Required systems.
18-28-502.1   General.
18-28-502.1.1   Exhaust location.
18-28-502.1.2   Fuel-dispensing areas.
18-28-502.1.3   Equipment, appliance and service rooms.
18-28-502.1.4   Hazardous exhaust.
18-28-502.2   Aircraft fueling and defueling.
18-28-502.3   Battery-charging areas.
18-28-502.4   Stationary lead-acid battery systems.
18-28-502.4.1   Hydrogen limit.
18-28-502.4.2   Ventilation rate.
18-28-502.5   Dry cleaning plants.
18-28-502.5.1   Type II systems.
18-28-502.5.2   Type IV and V systems.
18-28-502.5.3   Spotting and pretreating.
18-28-502.6   Application of flammable finishes.
18-28-502.6.1   During construction.
18-28-502.6.2   Limited spraying spaces.
18-28-502.6.3   Spraying areas.
18-28-502.6.3.1   Operation.
18-28-502.6.3.2   Recirculation.
18-28-502.6.3.3   Air velocity.
18-28-502.6.3.4   Ventilation obstruction.
18-28-502.6.3.5   Independent ducts.
18-28-502.6.3.6   Termination point.
18-28-502.6.3.7   Fan motors and belts.
18-28-502.6.4   Dipping operations.
18-28-502.6.5   Electrostatic apparatus.
18-28-502.6.6   Powder coating.
18-28-502.6.7   Floor resurfacing operations.
18-28-502.7   Hazardous materials – general requirements.
18-28-502.7.1   Storage in excess of the maximum allowable quantities.
18-28-502.7.1.1   System requirements.
18-28-502.7.2   Gas rooms, exhausted enclosures and gas cabinets.
18-28-502.7.3   Indoor dispensing and use.
18-28-502.7.4   Indoor dispensing and use – point sources.
18-28-502.7.5   Closed systems.
18-28-502.8   Hazardous materials – requirements for specific materials.
18-28-502.8.1   Compressed gases – medical gas systems.
18-28-502.8.2   Corrosives.
18-28-502.8.3   Cryogenics.
18-28-502.8.4   Explosives.
18-28-502.8.5   Flammable and combustible liquids.
18-28-502.8.5.1   Vaults.
18-28-502.8.5.2   Storage rooms and warehouses.
18-28-502.8.5.3   Cleaning machines.
18-28-502.8.5.4   Use, dispensing and mixing.
18-28-502.8.5.5   Bulk plants or terminals.
18-28-502.8.5.5.1   General.
18-28-502.8.5.5.2   Basements and pits.
18-28-502.8.5.5.3   Dispensing of Class I liquids.
18-28-502.8.6   Highly toxic and toxic liquids.
18-28-502.8.6.1   Treatment system.
18-28-502.8.6.2   Open and closed systems.
18-28-502.8.7   High toxic and toxic compressed – any quantity.
18-28-502.8.7.1   Gas cabinets.
18-28-502.8.7.2   Exhausted enclosures.
18-28-502.8.8   Highly toxic and toxic compressed gases – quantities exceeding the maximum allowable per control area.
18-28-502.8.8.1   Ventilated areas.
18-28-502.8.8.2   Local exhaust for portable tanks.
18-28-502.8.8.3   Piping and controls – stationary tanks.
18-28-502.8.8.4   Gas rooms.
18-28-502.8.8.5   Treatment system.
18-28-502.8.8.6   Process equipment.
18-28-502.8.9   Ozone gas generators.
18-28-502.8.10   LP-gas distribution facilities.
18-28-502.8.10.1   Portable container use.
18-28-502.8.11   Silane gas.
18-28-502.9   Hazardous production materials (HPM).
18-28-502.9.1   Where required.
18-28-502.9.2   Penetrations.
18-28-502.9.3   Treatment systems.
18-28-502.10   Motion picture projectors.
18-28-502.10.1   Projectors with an exhaust discharge.
18-28-502.10.2   Projectors without exhaust connection.
18-28-502.11   Organic coating processes.
18-28-502.12   Public garages.
18-28-502.13   Motor vehicle operation.
18-28-502.14   Repair garages.
18-28-502.15   Repair garages for natural gas- and hydrogen-fueled vehicles.
18-28-502.15.1   Design.
18-28-502.15.2   Operation.
18-28-502.16   Tire rebuilding or recapping.
18-28-502.16.1   Buffing machines.
18-28-502.17   Specific rooms.
18-28-503   Motor and fans.
18-28-503.1   General.
18-28-503.2   Fans.
18-28-503.3   Equipment and appliances identification plate.
18-28-503.4   Corrosion-resistant fans.
18-28-504   Clothes dryer exhaust.
18-28-504.1   Installation.
18-28-504.2   Exhaust penetrations.
18-28-504.3   Cleanout.
18-28-504.4   Exhaust installation.
18-28-504.5   Makeup air.
18-28-504.6   Domestic clothes dryer ducts.
18-28-504.6.1   Maximum length.
18-28-504.6.2   Rough-in required.
18-28-504.7   Commercial clothes dryers.
18-28-505   Domestic kitchen exhaust equipment.
18-28-505.1   Domestic systems.
18-28-506   Commercial kitchen grease ducts and exhaust equipment.
18-28-506.1   General.
18-28-506.2   Corrosion protection.
18-28-506.3   Ducts serving Type I hoods.
18-28-506.3.1   Exhaust fans.
18-28-506.3.1.1   Fan motor.
18-28-506.3.2   Grease duct materials.
18-28-506.3.3   Joints, seams and penetrations of grease ducts.
18-28-506.3.3.1   Duct joint types.
18-28-506.3.3.2   Duct-to-hood joints.
18-28-506.3.3.3   Duct-to-exhaust fan connections.
18-28-506.3.3.4   Vibration isolation.
18-28-506.3.4   Grease duct supports.
18-28-506.3.5   Air velocity.
18-28-506.3.6   Separation of grease duct system.
18-28-506.3.7   Clearances.
18-28-506.3.8   Prevention of grease accumulation.
18-28-506.3.9   Cleanouts and other openings.
18-28-506.3.9.1   Personnel entry.
18-28-506.3.10   Horizontal cleanouts.
18-28-506.3.11   Duct enclosure.
18-28-506.3.12   Fire-resistive access opening.
18-28-506.3.13   Type I exhaust outlets.
18-28-506.3.13.1   Termination above the roof.
18-28-506.3.13.2   Termination through an exterior wall.
18-28-506.3.13.3   Termination location.
18-28-506.4   Ducts serving Type II hoods.
18-28-506.4.1   Type II exhaust outlets.
18-28-506.4.2   Ducts.
18-28-507   Commercial kitchen hoods.
18-28-507.1   General.
18-28-507.2   Where required.
18-28-507.2.1   Type I and Type II hoods.
18-28-507.2.2   Domestic cooking appliances used for commercial purposes.
18-28-507.2.3   Solid fuel.
18-28-507.3   Fuel-burning appliances.
18-28-507.4   Type I materials.
18-28-507.5   Type II hood materials.
18-28-507.6   Supports.
18-28-507.7   Hood joints, seams and penetrations.
18-28-507.7.1   Type I hoods.
18-28-507.7.2   Type II hoods.
18-28-507.8   Cleaning and grease gutters.
18-28-507.9   Clearances for Type I hood.
18-28-507.10   Hoods penetrating a ceiling.
18-28-507.11   Grease filters.
18-28-507.11.1   Criteria.
18-28-507.11.2   Mounting position.
18-28-507.12   Canopy size and location.
18-28-507.13   Capacity of hoods.
18-28-507.13.1   Solid fuel-burning cooking appliances.
18-28-507.13.2   High temperature.
18-28-507.13.3   Medium temperature.
18-28-507.13.4   Low temperature.
18-28-507.14   Noncanopy size and location.
18-28-507.15   Capacity for noncanopy hoods.
18-28-507.16   Exhaust outlets.
18-28-507.17   Performance test.
18-28-508   Commercial kitchen makeup air.
18-28-508.1   Makeup air.
18-28-508.1.1   Makeup air temperature.
18-28-508.2   Compensating hoods.
18-28-509   Fire suppression systems.
18-28-509.1   Where required.
18-28-510   Hazardous exhaust systems.
18-28-510.1   General.
18-28-510.2   Where required.
18-28-510.2.1   Lumber yards and woodworking facilities.
18-28-510.2.2   Combustible fibers.
18-28-510.3   Design and operation.
18-28-510.4   Independent system.
18-28-510.5   Design.
18-28-510.5.1   Balancing.
18-28-510.5.2   Emission control.
18-28-510.5.3   Hoods required.
18-28-510.5.4   Contaminant capture and dilution.
18-28-510.5.5   Makeup air.
18-28-510.5.6   Clearances.
18-28-510.5.7   Ducts.
18-28-510.6   Penetrations.
18-28-510.7   Suppression required.
18-28-510.8   Duct construction.
18-28-510.8.1   Duct joints.
18-28-510.8.2   Clearance to combustibles.
18-28-510.8.3   Explosion relief.
18-28-510.9   Supports.
18-28-511   Dust, stock and refuse conveying systems.
18-28-511.1   Dust, stock and refuse conveying systems.
18-28-511.1.1   Collectors and separators.
18-28-511.1.2   Discharge pipe.
18-28-511.1.3   Conveying system exhaust discharge.
18-28-511.1.4   Spark protection.
18-28-511.1.5   Explosion relief vents.
18-28-511.1.5.1   Screens.
18-28-511.1.5.2   Hoods.
18-28-511.2   Exhaust outlets.
18-28-512   Subslab soil exhaust systems.
18-28-512.1   General.
18-28-512.2   Materials.
18-28-512.3   Grade.
18-28-512.4   Termination.
18-28-512.5   Identification.
18-28-513   Smoke control systems.
18-28-513.1   High-rise buildings.
Article VI.  Duct Systems
18-28-601   General.
18-28-601.1   Scope.
18-28-601.2   Deliberately omitted.
18-28-601.3   Contamination prevention.
18-28-602   Plenums.
18-28-602.1   General.
18-28-602.1.1   Technology centers and telecommunication equipment areas.
18-28-602.2   Construction.
18-28-602.2.1   Materials exposed within plenums.
18-28-602.3   Stud cavity and joist space plenums.
18-28-602.4   Deliberately omitted.
18-28-603   Duct construction and installation.
18-28-603.1   General.
18-28-603.2   Duct classification.
18-28-603.3   Metallic ducts.
18-28-603.4   Deliberately omitted.
18-28-603.4.1   Gypsum ducts.
18-28-603.5   Deliberately omitted.
18-28-603.5.1   Flexible air ducts.
18-28-603.5.1.1   Duct length.
18-28-603.5.2   Flexible air connectors.
18-28-603.6   Deliberately omitted.
18-28-603.7   Underground ducts.
18-28-603.7.1   Slope.
18-28-603.7.2   Sealing.
18-28-603.8   Joints and connections.
18-28-603.9   Supports.
18-28-603.10   Furnace connections.
18-28-603.11   Condensation.
18-28-603.12   Locations.
18-28-603.13   Mechanical protection.
18-28-603.14   Weather protection.
18-28-603.15   Registers, grilles and diffusers.
18-28-603.15.1   Floor registers.
18-28-604   Insulation.
18-28-604.1   General.
18-28-604.2   Surface temperature.
18-28-604.3   Covering and linings.
18-28-604.4   Deliberately omitted.
18-28-604.5   Deliberately omitted.
18-28-604.6   Deliberately omitted.
18-28-604.7   Identification.
18-28-604.8   Lining installation.
18-28-604.9   Thermal continuity.
18-28-604.10   Service openings.
18-28-604.11   Vapor retarders.
18-28-604.12   Weatherproof barriers.
18-28-604.13   Internal insulation.
18-28-605   Deliberately omitted.
18-28-606   Smoke detection systems control.
18-28-606.1   Control.
18-28-606.2   Where required.
18-28-606.2.1   Return air systems.
18-28-606.2.2   Common supply and return air systems.
18-28-606.2.3   Return air risers.
18-28-606.3   Installation.
18-28-606.4   Controls operation.
18-28-606.4.1   Connection to fire alarm system.
18-28-607   Ducts and air transfer openings.
Article VII.  Combustion Air
18-28-701   General.
18-28-701.1   Scope.
18-28-701.2   Combustion and dilution air required.
18-28-701.3   Circulation of air.
18-28-701.4   Crawl space and attic space.
18-28-701.4.1   Crawl space.
18-28-701.4.2   Attic space.
18-28-701.5   Prohibited sources.
18-28-702   Air requirements for equipment located in unconfined spaces.
18-28-702.1   Unconfined spaces.
18-28-703   Air requirements for equipment located in confined spaces.
18-28-703.1   Confined spaces.
18-28-703.2   Indoor air.
18-28-703.3   Outdoor air.
18-28-704   Deliberately Omitted.
18-28-705   Engineered installations.
18-28-706   Forced combustion air supply.
18-28-706.1   Mechanical combustion air supply for oil-fired appliances.
18-28-706.2   Mechanical combustion air supply for gas-fired appliances.
18-28-707   Direct connection.
18-28-707.1   General.
18-28-708   Combustion air ducts.
18-28-708.1   General.
18-28-709   Opening obstructions.
18-28-709.1   General.
18-28-709.2   Dampered openings.
18-28-710   Opening location and protection.
18-28-710.1   General.
18-28-711   Carbon monoxide detectors.
18-28-711.1   Carbon monoxide alarms.
Article VIII.  Chimneys and Vents
18-28-801   Scope.
18-28-801.1   Scope.
18-28-801.2   General.
18-28-801.2.1   Oil-fired appliances.
18-28-801.3   Masonry chimneys
18-28-801.4   Positive flow.
18-28-801.5   Design.
18-28-801.6   Minimum size of chimney or vent.
18-28-801.7   Solid fuel appliance flues.
18-28-801.8   Abandoned inlet openings.
18-28-801.9   Positive pressure.
18-28-801.10   Connection to fireplace.
18-28-801.10.1   Closure and access.
18-28-801.10.2   Connection to factory-built fireplace flue.
18-28-801.10.3   Connection to masonry fireplace flue.
18-28-801.11   Multiple solid fuel prohibited.
18-28-801.12   Chimney entrance.
18-28-801.13   Cleanouts.
18-28-801.14   Connections to exhauster.
18-28-801.15   Fuel-fired appliances.
18-28-801.16   Flue lining.
18-28-801.16.1   Residential and low-heat appliances (general).
18-28-801.17   Space around lining.
18-28-801.18   Existing chimneys and vents.
18-28-801.18.1   Size.
18-28-801.18.2   Flue passageways.
18-28-801.18.3   Cleanout.
18-28-801.18.4   Clearances.
18-28-801.19   Multistory prohibited.
18-28-802   Vents.
18-28-802.1   General.
18-28-802.2   Vent application.
18-28-802.3   Installation.
18-28-802.4   Vent termination caps required.
18-28-802.5   Type L vent terminations.
18-28-802.6   Minimum vent heights.
18-28-802.7   Support of vents.
18-28-802.8   Installation shield.
18-28-803   Connectors.
18-28-803.1   Connectors required.
18-28-803.2   Location.
18-28-803.3   Size.
18-28-803.4   Branch connectors.
18-28-803.5   Manual dampers.
18-28-803.6   Automatic dampers.
18-28-803.7   Connectors serving two or more appliances.
18-28-803.8   Vent connector construction.
18-28-803.9   Chimney connector construction.
18-28-803.10   Installation.
18-28-803.10.1   Supports and joints.
18-28-803.10.2   Length.
18-28-803.10.3   Connection.
18-28-803.10.4   Connector pass-through.
18-28-803.10.5   Pitch.
18-28-803.10.6   Clearances.
18-28-804   Direct-vent, integral vent, mechanical vent and ventilation/exhaust hood venting.
18-28-804.1   Direct-vent terminations.
18-28-804.2   Appliances with integral vents.
18-28-804.2.1   Terminal clearances.
18-28-804.3   Mechanical draft systems.
18-28-804.3.1   Forced draft systems.
18-28-804.3.2   Automatic shutoff.
18-28-804.3.3   Termination.
18-28-804.3.4   Horizontal terminations.
18-28-804.3.5   Vertical terminations.
18-28-804.3.6   Exhauster connections.
18-28-804.3.7   Exhauster sizing.
18-28-805   Factory-built chimneys.
18-28-805.1   Listing.
18-28-805.2   Solid fuel appliances.
18-28-805.3   Factory-built fireplaces.
18-28-805.4   Support.
18-28-805.5   Medium-heat appliances.
18-28-805.6   Decorative shrouds.
18-28-806   Metal chimneys.
18-28-806.1   General.
18-28-807   Engine generator exhaust systems.
18-28-807.1   [No caption.]
18-28-807.2   Exhaust systems termination.
Article IX.  Specific Appliances, Fireplaces and Solid Fuel-Burning Equipment
18-28-901   General.
18-28-901.1   Scope.
18-28-901.2   General.
18-28-901.3   Hazardous locations.
18-28-901.4   Fireplace accessories.
18-28-901.5   Installation in private garages.
18-28-901.6   Borrowed light concept.
18-28-902   Masonry fireplaces.
18-28-902.1   General.
18-28-902.2   Masonry fireplaces utilizing wood or other solid fuels.
18-28-902.3   Gas-fired log lighters.
18-28-902.3.1   Approval and installation.
18-28-902.3.2   Prohibited installations.
18-28-902.3.3   Combustion and circulating air.
18-28-903   Factory-built fireplaces.
18-28-903.1   General.
18-28-903.1.1   Additional combustion air.
18-28-903.1.2   Direct vent fireplaces.
18-28-903.1.3   Vented gas fireplaces (not including direct vent) located in habitable rooms (not including bathrooms and sleeping rooms).
18-28-903.1.4   Vented gas fireplaces (not including direct vent) located in bathrooms and sleeping rooms.
18-28-903.1.5   Unvented gas fireplaces.
18-28-903.2   Hearth extensions.
18-28-903.3   Unvented gas log heaters.
18-28-903.3.1   Decorative appliances for installation in vented fireplaces.
18-28-903.3.1.1   Prohibited installations.
18-28-903.3.1.2   Installation.
18-28-903.3.1.3   [No caption.]
18-28-903.3.1.4   [No caption.]
18-28-903.3.1.5   Fireplace screens.
18-28-903.3.2   Gas-fired log lighters.
18-28-903.3.2.1   Approval and installation.
18-28-903.3.2.2   Prohibited installations.
18-28-903.3.2.3   Combustion and circulating air.
18-28-904   Pellet fuel-burning appliances.
18-28-904.1   General.
18-28-905   Fireplace stoves and room heaters.
18-28-905.1   General.
18-28-905.1.1   Additional combustion air.
18-28-905.1.2   Direct vent gas room heaters.
18-28-905.1.3   Unvented gas room heaters.
18-28-905.2   Connection fireplace.
18-28-906   Factory-built barbecue appliances.
18-28-906.1   General.
18-28-906.2   Natural gas barbecue grills located on balconies of multi-family buildings.
18-28-907   Incinerators and crematories.
18-28-907.1   General.
18-28-908   Cooling towers, evaporative condensers and fluid coolers.
18-28-908.1   General.
18-28-908.2   Access.
18-28-908.3   Location.
18-28-908.4   Support and anchorage.
18-28-908.5   Water supply.
18-28-908.6   Drainage.
18-28-908.7   Refrigerants and hazardous fluids.
18-28-909   Vented wall furnaces.
18-28-909.1   General.
18-28-909.2   Location.
18-28-909.3   Door swing.
18-28-909.4   Ducts prohibited.
18-28-909.5   Manual shutoff valve.
18-28-909.6   Access.
18-28-909.7   Combustion and circulating air.
18-28-909.8   Gas-fired vented wall furnaces.
18-28-909.9   Gas-fired direct-vent wall furnaces.
18-28-910   Floor furnaces.
18-28-910.1   General.
18-28-910.2   Placement.
18-28-910.3   Bracing.
18-28-910.4   Clearance.
18-28-911   Duct furnaces.
18-28-911.1   General.
18-28-911.2   Gas-fired duct furnaces.
18-28-911.2.1   Clearances.
18-28-911.2.2   Erection of equipment.
18-28-911.2.3   Access panels.
18-28-911.2.4   Location of draft hood and controls.
18-28-911.2.5   Circulating air.
18-28-911.2.6   Duct furnaces used with refrigeration systems.
18-28-912   Infrared radiant heaters.
18-28-912.1   Support.
18-28-912.2   Clearances.
18-28-912.3   Installation in commercial garages.
18-28-912.3.1   Parking structures.
18-28-912.3.2   Repair garages.
18-28-912.3.3   Installation in aircraft hangars.
18-28-913   Clothes dryers.
18-28-913.1   General.
18-28-913.2   Exhaust required.
18-28-913.3   Clearances.
18-28-914   Sauna heaters.
18-28-914.1   Location and protection.
18-28-914.1.1   Guards.
18-28-914.2   Installation.
18-28-914.2.1   Combustion and dilution air intakes.
18-28-914.2.2   Combustion and ventilation air.
18-28-914.3   Access.
18-28-914.4   Heat and time controls.
18-28-914.4.1   Timers.
18-28-914.5   Sauna room.
18-28-914.5.1   Warning notice.
18-28-915   Engine and gas turbine-powered equipment and appliances.
18-28-915.1   General.
18-28-916   Pool and spa heaters.
18-28-916.1   General.
18-28-916.2   Gas-fired pool heaters.
18-28-916.2.1   Location.
18-28-916.2.2   Clearance.
18-28-916.2.3   Temperature- or pressure-limiting devices.
18-28-916.2.3.1   [No caption.]
18-28-916.2.3.2   Bypass valves.
18-28-916.2.3.3   Venting.
18-28-917   Cooking appliances.
18-28-917.1   Cooking appliances.
18-28-917.2   Prohibited location.
18-28-917.3   Domestic appliances.
18-28-917.4   Gas-fired food service equipment, floor-mounted.
18-28-917.4.1   Clearance for listed equipment.
18-28-917.4.2   Clearance for unlisted equipment.
18-28-917.4.3   Mounting on combustible floor.
18-28-917.4.4   Mounting on noncombustible floor.
18-28-917.4.5   Combustible material adjacent to cooking top.
18-28-917.4.6   For use with casters.
18-28-917.4.7   Level installation.
18-28-917.4.8   Ventilation.
18-28-917.5   Gas-fired food service equipment – counter appliances.
18-28-917.5.1   Vertical clearance.
18-28-917.5.2   Clearance for listed appliances.
18-28-917.5.3   Clearance for unlisted appliances.
18-28-917.5.4   Mounting of unlisted appliances.
18-28-917.6   Gas-fired hot plates.
18-28-917.7   Gas-fired household cooking appliances.
18-28-917.7.1   Floor-mounted units.
18-28-917.7.1.1   Clearance from combustible material.
18-28-917.7.1.2   Vertical clearance above cooking top.
18-28-917.7.1.3   Level installation.
18-28-917.7.2   Built-in units.
18-28-917.7.2.1   Installation.
18-28-917.7.2.2   Vertical clearance.
18-28-917.7.2.3   Horizontal clearance.
18-28-917.7.2.4   Level installation.
18-28-917.8   Gas-fired open-top broiler units.
18-28-917.8.1   Listed units.
18-28-917.8.2   Unlisted units.
18-28-917.8.3   Protection above domestic units.
18-28-917.8.4   Commercial units.
18-28-918   Forced-air warm-air furnaces.
18-28-918.1   Forced-air furnaces.
18-28-918.2   Minimum duct sizes.
18-28-918.3   Heat pumps.
18-28-918.4   Dampers.
18-28-918.5   Circulating air ducts for forced-air warm-air furnaces.
18-28-918.6   Prohibited sources.
18-28-918.7   Outside opening protection.
18-28-918.8   Return-air limitation.
18-28-918.9   Gas-fired forced-air, warm-air furnaces.
18-28-918.9.1   General.
18-28-918.9.2   [No caption.]
18-28-918.9.3   Clearance.
18-28-918.9.4   Assembly and installation.
18-28-918.9.5   Combustion and circulating air.
18-28-918.9.6   Furnace plenums and air ducts.
18-28-918.10   Gas-fired horizontal furnaces above dropped ceilings.
18-28-918.11   Gas-fired furnaces located above bathrooms, toilet rooms or bedrooms.
18-28-919   Conversion burners.
18-28-919.1   Conversion burners.
18-28-920   Unit heaters.
18-28-920.1   General.
18-28-920.2   Support.
18-28-920.3   Ductwork.
18-28-920.4   Gas-fired unit heaters.
18-28-920.4.1   Support.
18-28-920.4.2   Clearance.
18-28-920.4.2.1   Suspended-type unit heaters.
18-28-920.4.2.2   Floor-mounted-type unit heaters.
18-28-920.4.3   Combustion and circulating air.
18-28-920.4.4   Ductwork.
18-28-920.4.5   Installation in commercial garages.
18-28-920.4.5.1   Parking structures.
18-28-920.4.5.2   Repair garages.
18-28-920.4.6   Installation in aircraft hangars.
18-28-921   Vented room heaters.
18-28-921.1   General.
18-28-922   Kerosene and oil-fired stoves.
18-28-922.1   General.
18-28-923   Small ceramic kilns.
18-28-923.1   General.
18-28-923.1.1   Installation.
18-28-924   Stationary fuel cell power plants.
18-28-924.1   General.
18-28-924.2   Natural gas energized fuel cell power plants.
18-28-925   Gas-fired air conditioners.
18-28-925.1   Independent gas piping.
18-28-925.2   Connection of gas engine-powered air conditioners.
18-28-925.3   Clearances for indoor installation.
18-28-925.4   Assembly and installation.
18-28-925.5   Furnace plenums and air ducts.
18-28-926   Non-recirculating direct gas-fired industrial air heaters.
18-28-926.1   Application.
18-28-926.2   Prohibited installations.
18-28-926.3   Installation.
18-28-926.4   Clearance from combustible materials.
18-28-926.5   Air supply.
18-28-926.6   Atmospheric vents or gas reliefs or bleeds.
18-28-926.7   Relief openings.
18-28-926.8   Purging.
18-28-927   Recirculating direct gas-fired industrial air heaters.
18-28-927.1   Application.
18-28-927.2   Prohibited installations.
18-28-927.3   Installation.
18-28-927.4   Clearance from combustible materials.
18-28-927.5   Air supply.
18-28-927.6   Atmospheric vents, gas reliefs, or bleeds.
18-28-927.7   Relief openings.
18-28-927.8   Purging.
18-28-928   Gas-fired illuminating appliances.
18-28-928.1   Clearances for listed appliances.
18-28-928.2   Clearances for unlisted appliances.
18-28-928.2.1   Enclosed type.
18-28-928.2.2   Open-flame type.
18-28-928.3   Mounting on buildings.
18-28-928.4   Mounting on posts.
18-28-928.5   Gas appliance pressure regulators.
18-28-929   Appliances for installation in manufactured housing.
Article X.  Boilers, Water Heaters and Pressure Vessels
18-28-1001   General.
18-28-1001.1   Scope.
18-28-1002   Water heaters.
18-28-1002.1   General.
18-28-1003   Unfired pressure vessels.
18-28-1003.1   General.
18-28-1003.2   Piping.
18-28-1003.3   Welding.
18-28-1004   Boilers.
18-28-1004.1   Standards.
18-28-1004.1.1   Non-boiler external piping.
18-28-1004.2   Installation.
18-28-1004.3   Working clearance.
18-28-1004.3.1   Top clearance.
18-28-1004.4   Mounting.
18-28-1004.5   Floors.
18-28-1004.6   Boiler rooms and enclosures.
18-28-1004.7   Operating adjustments and instructions.
18-28-1004.8   Stationary Engineers and Boiler Tenders.
18-28-1005   Boiler connections.
18-28-1005.1   Valves.
18-28-1005.2   Potable water supply.
18-28-1006   Safety and pressure relief valves and controls.
18-28-1006.1   Safety valve for steam boilers.
18-28-1006.2   Safety relief valves for hot water boilers.
18-28-1006.3   Pressure relief for pressure vessels.
18-28-1006.4   Approval of safety and safety relief valves.
18-28-1006.5   Installation.
18-28-1006.6   Safety and relief valve discharge.
18-28-1006.7   Boiler safety devices.
18-28-1006.8   Electrical requirements.
18-28-1007   Boiler low-water cutoff.
18-28-1007.1   General.
18-28-1007.2   Operation.
18-28-1008   Steam blowoff valve.
18-28-1008.1   General.
18-28-1008.2   Discharge.
18-28-1009   Hot water boiler expansion tank.
18-28-1009.1   Where required.
18-28-1009.2   Closed-type expansion tanks.
18-28-1009.3   Open-type expansion tanks.
18-28-1010   Gauges.
18-28-1010.1   Hot water boiler gauges.
18-28-1010.2   Steam boiler gauges.
18-28-1010.2.1   Water-gauge glass.
18-28-1011   Tests.
18-28-1011.1   Tests.
18-28-1011.2   Test gauges.
18-28-1012   Vessel repair.
18-28-1012.1   Qualification.
18-28-1012.2   Repair.
18-28-1012.3   High pressure boiler inspection and repair.
18-28-1013   Carbon monoxide detector.
Article XI.  Refrigeration
18-28-1101   General.
18-28-1101.1   Scope.
18-28-1101.2   Standards for Pressure Vessels.
18-28-1101.3   Protection.
18-28-1101.4   Fuel gas connection.
18-28-1101.5   Signage – General.
18-28-1101.6   Condensate disposal.
18-28-1101.7   General.
18-28-1101.8   Ammonia dump valve.
18-28-1101.9   Maintenance.
18-28-1101.10   Location of condensing unit.
18-28-1101.11   Stairways and exitways.
18-28-1101.12   General limitations.
18-28-1101.13   Refrigerant discharge.
18-28-1101.14   Safety equipment.
18-28-1101.15   Recirculation of water used for cooling purposes.
18-28-1102   System requirements.
18-28-1102.1   General.
18-28-1102.2   Refrigerants.
18-28-1102.2.1   Mixing.
18-28-1102.3   Pressure relief.
18-28-1102.3.1   Discharge piping.
18-28-1102.3.2   Sizing.
18-28-1103   Refrigeration system classification.
18-28-1103.1   Refrigerant classification.
18-28-1103.2   Occupancy classification.
18-28-1103.2.1   Institutional systems – general.
18-28-1103.2.2   Industrial systems – general.
18-28-1103.2.3   Commercial systems – general.
18-28-1103.2.4   Multiple dwelling systems – general.
18-28-1103.3   System classification.
18-28-1103.3.1   Low-probability systems.
18-28-1103.3.2   High-probability systems.
18-28-1104   System application requirements.
18-28-1104.1   General.
18-28-1104.2   Machine room.
18-28-1104.2.1   Institutional occupancies.
18-28-1104.2.2   Industrial occupancies and refrigerated rooms.
18-28-1104.2.3   Multiple dwelling location provisions.
18-28-1104.3   Refrigerant restrictions.
18-28-1104.3.1   Air-conditioning for human comfort.
18-28-1104.3.2   Nonindustrial occupancies.
18-28-1104.3.3   All occupancies.
18-28-1104.3.4   Protection from refrigerant decomposition.
18-28-1104.4   [No caption.]
18-28-1104.4.1   Nonconnecting spaces.
18-28-1104.4.2   Ventilated spaces.
18-28-1104.4.3   Closures.
18-28-1104.4.4   Plenums.
18-28-1104.4.5   Supply and return ducts.
18-28-1105   Machinery room general requirements.
18-28-1105.1   Access.
18-28-1105.2   Dimensions.
18-28-1105.3   Doors.
18-28-1105.4   Openings.
18-28-1105.5   Refrigerant detector.
18-28-1105.6   Tests.
18-28-1105.7   Fuel-burning appliance.
18-28-1105.8   Ventilation.
18-28-1105.8.1   Discharge location.
18-28-1105.8.2   Make-up air.
18-28-1105.8.3   Quantity – Normal ventilation.
18-28-1105.8.4   Quantity – Emergency conditions.
18-28-1105.9   Termination of relief devices.
18-28-1105.10   Ammonia discharge.
18-28-1105.11   Safety equipment.
18-28-1106   Machinery room special requirements.
18-28-1106.1   General.
18-28-1106.2   Elevated temperature.
18-28-1106.3   Construction requirements.
18-28-1106.4   Opening protectives.
18-28-1106.5   Pipe penetrations.
18-28-1106.6   Deliberately omitted.
18-28-1106.7   Egress.
18-28-1106.8   Ammonia room ventilation.
18-28-1106.9   Flammable refrigerants.
18-28-1106.10   Remote controls.
18-28-1106.10.1   Refrigeration system.
18-28-1106.10.2   Ventilation system.
18-28-1106.11   Fireman's dump system.
18-28-1106.12   Hand-operated emergency valves.
18-28-1106.12.1   Hand-operated emergency valve discharge – Group 1 refrigerants.
18-28-1106.13   Provisions for discharge of refrigerants.
18-28-1107   Refrigerant piping.
18-28-1107.1   General.
18-28-1107.2   Pipe enclosures.
18-28-1107.2.1   Location prohibition.
18-28-1107.3   Condensation.
18-28-1107.3.1   Cooling coil condensation requirements.
18-28-1107.4   Materials for refrigerants pipe and tubing.
18-28-1107.4.1   Steel pipe.
18-28-1107.4.2   Copper and brass pipe.
18-28-1107.4.3   Copper tube.
18-28-1107.4.4   Copper tube joints.
18-28-1107.4.5   Aluminum tube.
18-28-1107.5   Joints and refrigerant-containing parts in air ducts.
18-28-1107.6   Exposure of refrigerant pipe joints.
18-28-1107.7   Stop valves.
18-28-1107.7.1   Liquid receivers.
18-28-1107.7.2   Copper tubing.
18-28-1107.7.3   Identification.
18-28-1108   Field test.
18-28-1108.1   General.
Article XII.  Hydronic Piping
18-28-1200   General.
18-28-1201.1   Scope.
18-28-1201.2   Pipe sizing.
18-28-1202   Material.
18-28-1202.1   Piping.
18-28-1202.2   Used materials.
18-28-1202.3   Material rating.
18-28-1202.4   Piping materials standards.
18-28-1202.5   Pipe fittings.
18-28-1202.6   Valves.
18-28-1202.7   Flexible connectors, expansion and vibration compensators.
18-28-1203   Joints and connections.
18-28-1203.1   Approval.
18-28-1203.1.1   Joints between different piping materials.
18-28-1203.2   Preparation of pipe ends.
18-28-1203.3   Joint preparation and installation.
18-28-1203.3.1   Brazed joints.
18-28-1203.3.2   Mechanical joints.
18-28-1203.3.3   Soldered joints.
18-28-1203.3.4   Solvent-cemented joints.
18-28-1203.3.5   Threaded joints.
18-28-1203.3.6   Welded joints.
18-28-1203.3.7   Grooved and shouldered joints.
18-28-1203.4   ABS plastic pipe.
18-28-1203.5   Brass pipe.
18-28-1203.6   Brass tubing.
18-28-1203.7   Copper or copper-alloy pipe.
18-28-1203.8   Copper or copper-alloy tubing.
18-28-1203.8.1   Flared joints.
18-28-1203.9   CPVC plastic pipe.
18-28-1203.10   Polybutylene plastic pipe and tubing.
18-28-1203.10.1   Heat-fusion joints.
18-28-1203.11   Cross-linked polyethylene (PEX) plastic tubing.
18-28-1203.11.1   Compression-type fittings.
18-28-1203.11.2   Plastic-to-metal connections.
18-28-1203.12   PVC plastic pipe.
18-28-1203.13   Steel pipe.
18-28-1203.14   Steel tubing.
18-28-1204   Pipe insulation.
18-28-1204.1   Insulation characteristics.
18-28-1204.2   Required thickness.
18-28-1205   Valves.
18-28-1205.1   Where required.
18-28-1205.1.1   Heat exchangers.
18-28-1205.1.2   Central systems.
18-28-1205.1.3   Pressure vessels.
18-28-1205.1.4   Pressure-reducing valves.
18-28-1205.1.5   Equipment and appliances.
18-28-1205.1.6   Expansion tanks.
18-28-1205.2   Reduced pressure.
18-28-1206   Piping installation.
18-28-1206.1   General.
18-28-1206.1.1   Prohibited tee applications.
18-28-1206.2   System drain down.
18-28-1206.3   Protection of potable water.
18-28-1206.4   Pipe penetrations.
18-28-1206.5   Clearance to combustibles.
18-28-1206.6   Contact with building material.
18-28-1206.7   Water hammer.
18-28-1206.8   Steam piping pitch.
18-28-1206.9   Strains and stresses.
18-28-1206.9.1   Flood hazard.
18-28-1206.10   Pipe support.
18-28-1206.11   Condensation.
18-28-1207   Transfer fluid.
18-28-1207.1   Flash point.
18-28-1207.2   Makeup water.
18-28-1208   Tests.
18-28-1208.1   General.
18-28-1209   Embedded piping.
18-28-1209.1   Materials.
18-28-1209.2   Pressurizing during installation.
18-28-1209.3   Embedded joints.
18-28-1209.3.1   Steel pipe joints.
18-28-1209.3.2   Copper tubing joints.
18-28-1209.3.3   Polybutylene joints.
18-28-1209.4   Not embedded related piping.
Article XIII.  Fuel Oil Piping and Storage
18-28-1301   General.
18-28-1301.1   Scope.
18-28-1301.2   Storage systems.
18-28-1301.3   Fuel type.
18-28-1301.4   Fuel tanks, piping and valves.
18-28-1302   Material.
18-28-1302.1   General.
18-28-1302.2   Rated for system.
18-28-1302.3   Storage tanks.
18-28-1302.4   Pipe standards.
18-28-1302.5   Nonmetallic pipe.
18-28-1302.6   Fittings and valves.
18-28-1302.7   Bending of pipe.
18-28-1302.8   Pumps.
18-28-1302.9   Flexible connectors and hoses.
18-28-1303   Joints and connections.
18-28-1303.1   Approval.
18-28-1303.1.1   Joints between different piping materials.
18-28-1303.2   Preparation of pipe ends.
18-28-1303.3   Joint preparation and installation.
18-28-1303.3.1   Brazed joints.
18-28-1303.3.2   Mechanical joints.
18-28-1303.3.3   Threaded joints.
18-28-1303.3.4   Welded joints.
18-28-1303.4   Brass pipe.
18-28-1303.5   Brass tubing.
18-28-1303.6   Copper or copper-alloy pipe.
18-28-1303.7   Copper or copper-alloy tubing.
18-28-1303.8   Nonmetallic pipe.
18-28-1303.9   Steel pipe.
18-28-1303.9.1   Mechanical joints.
18-28-1303.10   Steel tubing.
18-28-1303.11   Piping protection.
18-28-1304   Piping support.
18-28-1304.1   General.
18-28-1305   Fuel oil system installation.
18-28-1305.1   Size.