Parts 5 to 7 items: BCIN Detection, Lighting and Power

Last updated October 22, 2026

Values this chapter turns on

standby battery power for a CO alarm: 8 h; standby battery power for a CO alarm
CO alarm signal time after the standby period: 12 h; CO alarm signal time after the standby period
max spacing of CO alarms along a public corridor: 25 m; max spacing of CO alarms along a public corridor
pipe temperature up to which no clearance is needed: 95°C; pipe temperature up to which no clearance is needed

This section picks a few items from Parts 5, 6 and 7 that touch detection and electrical work. They include fan installation, laboratory exhaust monitoring, duct smoke detectors and carbon monoxide alarms, solar collectors and solar hot water, and the tracer wire on plastic water services. Most questions here are short lookups, so the skill being tested is knowing which Part to open.

HVAC: duct clearances, fans and laboratory ventilation

General installation OBC Div. B 6.2.1.6.:

HVAC equipment that needs periodic maintenance must have access for inspection, maintenance, repair and cleaning;
mechanical equipment needs guards to prevent injury;
systems that freezing could affect must be protected from freezing.

Duct and plenum clearances. Part 6 sends these to Article 3.6.5.6. OBC Div. B 6.3.2.6., the same clearance ladder used in Chapter 8. For bare steam and hot water pipes, Table 6.7.1.2. sets the clearance to combustible material by water temperature OBC Div. B 6.7.1.2.. Up to 95°C, no clearance is needed. The table steps up to 25 mm above 120°C.

Fans. HVAC fans must not upset the draft of fuel-fired appliances, and must not let boiler room or furnace room air or gases contaminate the ducts. Fans and air-handling equipment mounted on a roof or elsewhere outdoors must be of a type designed for outdoor use OBC Div. B 6.3.2.17..

Laboratories using dangerous goods Subsection 6.3.4. applies where flammable or combustible liquids or other dangerous goods are used in quantities or ways that create a fire or explosion hazard.

Lab ventilation item	Requirement
General ventilation	Continuous mechanical, exhausted outdoors, never returned to the building
Monitoring	Devices that show the system is running and sound an alarm on malfunction
Power-ventilated enclosure (fume hood) exhaust	Conforms to NFPA 91; continuous; control switches outside the enclosure and readily accessible
Enclosure materials	Noncombustible, unless corrosion needs require combustible material with flame-spread 25 or less (more if the enclosure has fire suppression)

See OBC Div. B 6.3.4.3. and 6.3.4.4..

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Duct smoke detectors and carbon monoxide alarms

Duct smoke detectors. Part 6 does not set its own triggers. Air-handling systems include smoke detectors where and as 3.2.4.12. requires OBC Div. B 6.9.2.2.. Where a fire alarm system is installed, that means a system serving more than one storey, more than one suite on a storey, more than one required fire compartment, or lacking the fire dampers allowed by 3.1.8.8.(4).

Carbon monoxide alarms. A CO alarm is a CO detection device with an integral audible alarm that sounds within its room, suite or space (Div. A). Under OBC Div. B 6.9.3.1., the suite rules in 6.9.3.2. apply to two kinds of building:

a building with a residential occupancy or a care occupancy, plus a fuel-burning appliance or a storage garage; or
a residential building served by a forced-air fuel-burning appliance located outside it.

The service room rule (6.9.3.3.) and the installation rule (6.9.3.4.) apply to every building.

A suite needs CO alarms under OBC Div. B 6.9.3.2. when any of these applies:

a fuel-burning appliance or flue is in the suite;
a forced-air fuel-burning appliance supplies heated air directly to it;
a fuel-burning appliance or flue is in a space that shares a wall, floor or ceiling with it;
a storage garage shares a wall, floor or ceiling with it.

Locations in the suite:

Suite layout	CO alarm locations
Separate sleeping rooms	Adjacent to each sleeping room, plus one on each storey without a sleeping room
Combined living and sleeping area	In that combined area
Sleeping room that contains, or adjoins outside the suite, a fuel-burning appliance, flue or storage garage	Also inside that sleeping room
Public corridor heated directly by forced air	At least one per portion of a divided corridor; not more than 25 m apart

Worked example

A 2-storey apartment suite has its own gas furnace, with both bedrooms upstairs. The furnace triggers the suite rule. CO alarms go adjacent to each bedroom upstairs and one on the lower storey, which has no sleeping room. Neither bedroom adjoins a CO source, so none is needed inside a bedroom. If the building also has a gas boiler room serving common areas, that room needs its own CO alarm under OBC Div. B 6.9.3.3.. This applies even in an office building.

Installation OBC Div. B 6.9.3.4.:

permanently wired, with no disconnect switch;
a battery that gives 8 h of standby and then at least 12 h of alarm;
interconnected within the suite, and along a corridor;
audible in sleeping rooms with the doors closed;
conforming to CAN/CSA-6.19 or UL 2034;
mounted at the manufacturer's recommended height, or on or near the ceiling if no height is given.

Battery-only alarms are allowed where the building has no electrical power. Visual signals in sleeping areas must be at least 175 cd.

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Solar systems and tracer wire

Solar collector systems may be installed above roofing that conforms to Table 5.9.1.1. OBC Div. B 5.6.2.3.. Even on a building required to be of noncombustible construction, a combustible collector system is permitted above the roof OBC Div. B 3.1.5.28..
Solar water heating equipment conforms to CAN/CSA-F379 SERIES OBC Div. B 7.2.10.13., and the systems are installed to CAN/CSA-F383 OBC Div. B 7.6.1.8.. One standard covers the equipment and the other covers installation.
A non-metallic water service pipe or fire service main needs a light coloured, plastic coated tracer wire. Use either 14 gauge TW solid copper or 12 gauge copper clad steel. The wire may be left off only where the pipe can be detected without it OBC Div. B 7.2.11.3..
Plumbing fixtures may only go in rooms lit and ventilated to Parts 3, 6 and 9, and fixtures and equipment must be readily accessible Subsection 7.1.3..

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Common traps

Thinking Part 6 sets its own duct detector triggers. It defers entirely to 3.2.4.12.
Limiting CO alarms to residential buildings. A service room with a fuel-burning appliance for building services or laundry drying needs one in any building.
Using the smoke alarm battery period (7 days plus 4 minutes) for CO alarms. CO alarms need 8 h of standby plus 12 h of alarm.
Swapping F379 and F383: equipment versus installation.
Placing CO alarms inside every bedroom. The base rule is adjacent to each sleeping room; inside is added only for bedrooms that contain or adjoin a CO source.

Chapter review

Chapter at a glance

One line per section: the idea to carry into the exam. Then the answers that most often catch candidates out.

Chapter at a glance: the key idea in each section
Section	Key idea
HVAC: duct clearances, fans and laboratory ventilation	Laboratories using dangerous goods applies where flammable or combustible liquids or other dangerous goods are used in quantities or ways that create a fire or explosion hazard.
Duct smoke detectors and carbon monoxide alarms	The service room rule (6.9.3.3.) and the installation rule (6.9.3.4.) apply to every building.

HVAC: duct clearances, fans and laboratory ventilation
Laboratories using dangerous goods applies where flammable or combustible liquids or other dangerous goods are used in quantities or ways that create a fire or explosion hazard.
Duct smoke detectors and carbon monoxide alarms
The service room rule (6.9.3.3.) and the installation rule (6.9.3.4.) apply to every building.

Usual exam traps

Thinking Part 6 sets its own duct detector triggers. It defers entirely to 3.2.4.12.
Limiting CO alarms to residential buildings. A service room with a fuel-burning appliance for building services or laundry drying needs one in any building.
Using the smoke alarm battery period (7 days plus 4 minutes) for CO alarms. CO alarms need 8 h of standby plus 12 h of alarm.
Swapping F379 and F383: equipment versus installation.
Placing CO alarms inside every bedroom. The base rule is adjacent to each sleeping room; inside is added only for bedrooms that contain or adjoin a CO source.

Practice this chapter

Questions on Parts 5 to 7 items, in the exam format, every answer explained and cited to its article. Sign in to start; a free account gets the free questions.

Practice this chapter Free Detection, Lighting and Power quiz

Code cited in this chapter

Based on the official 2024 Building Code Compendium on ontario.ca.

OBC Div. B 6.2.1.6. Installation — General
(1)Equipment requiring periodic maintenance and forming part of a heating, ventilating or air-conditioning system shall be installed with provision for access for inspection, maintenance, repair and cleaning. (See Note A-6.2.1.6.(1))
(2)Mechanical equipment shall be provided with guards so as to prevent injury.
(3)Heating, ventilating or air-conditioning systems shall be protected from freezing if they may be adversely affected by freezing temperatures.
Open OBC Div. B 6.2.1.6. in the code viewer
OBC Div. B 6.3.2.6. Clearance of Ducts and Plenums
(1)The clearance of ducts and plenums from combustible materials shall comply with Article 3.6.5.6.
Open OBC Div. B 6.3.2.6. in the code viewer
OBC Div. B 6.7.1.2. Clearances
(1)Clearances between combustible material and bare pipes carrying steam or hot water shall conform to Table 6.7.1.2.
Open OBC Div. B 6.7.1.2. in the code viewer
OBC Div. B 6.3.2.17. Fans and Associated Air-Handling Equipment
(1)Fans for heating, ventilating and air-conditioning systems shall be located and installed so that their operation
(a)does not adversely affect the draft required for proper operation of fuel-fired appliances, and
(b)does not allow the air in the duct system to be contaminated by air or gases from the boiler room or furnace room.
(2)Fans and associated air-handling equipment, such as air washers, filters and heating and cooling units, when installed on the roof or elsewhere outside the building, shall be of a type designed for outdoor use.
Open OBC Div. B 6.3.2.17. in the code viewer
OBC Div. B 6.3.4.2. General Ventilation
(1)A laboratory shall be provided with continuous mechanical ventilation designed to ensure that dangerous goods vapours and particles
(a)do not accumulate in the laboratory,
(b)are prevented from migrating to other parts of the building,
(c)do not accumulate in the ventilation system,
(d)are exhausted to the outdoors, and
(e)are not returned to the building.
(2)A ventilation system required by this Subsection shall be provided with monitoring devices to
(a)indicate that the ventilation system is in operation, and
(b)sound an alarm if the ventilation system is malfunctioning.
(3)A ventilation system required by this Subsection shall be maintained in conformance with Section 4.12. of the Fire Code made under the Fire Protection and Prevention Act, 1997.
Open OBC Div. B 6.3.4.2. in the code viewer
OBC Div. B 6.3.4.3. Enclosure Exhaust Ventilation
(1)The ventilation system for a power-ventilated enclosure referred to in Article 6.3.4.2A. shall
(a)conform to NFPA 91, "Standard for Exhaust Systems for Air Conveying of Vapors, Gases, Mists, and Particulate Solids."
(b)provide continuous exhaust ventilation at an air velocity sufficient to prevent the accumulation of combustible or reactive deposits in the power-ventilated enclosure and its exhaust duct system,
(c)confine dangerous goods vapours and particles to the area where they are generated and exhaust them to the outdoors.
(d)not return the exhausted air to the building, and
(e)be provided with well identified control switches that are
(i)located outside the power-ventilated enclosure, and
(ii)readily accessible in case of an emergency.
Open OBC Div. B 6.3.4.3. in the code viewer
OBC Div. B 6.3.4.4. Enclosure Construction
(1)The power-ventilated enclosure referred to in Article 6.3.4.2A. and its exhaust duct system shall
(a)except as provided in Sentences (2) and (3), be constructed of noncombustible materials compatible with and chemically resistant to the dangerous goods vapours and particles being exhausted, and
(b)be provided with access doors to permit inspection and maintenance of the fan assembly and exhaust ducts.
(2)Combustible materials are permitted in the power-ventilated enclosure described in Sentence (1) and its exhaust duct systems if
(a)such materials are required by the corrosive or reactive properties of the dangerous goods being used, and
(b)their flame-spread rating is not more than 25.
(3)The flame-spread rating required by Sentence (2) is permitted to be greater than 25 if an automatic fire suppression system is provided inside the power-ventilated enclosure and its exhaust duct system.
Open OBC Div. B 6.3.4.4. in the code viewer
OBC Div. B 6.9.2.2. Smoke Detectors
(1)Air handling systems shall incorporate smoke detectors where and as required by Article 3.2.4.12.
Open OBC Div. B 6.9.2.2. in the code viewer

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OBC Div. A 1.4.1.2.(1) Carbon monoxide alarm
Carbon monoxide alarm means a carbon monoxide detection device with an integral audible alarm device designed to sound an alarm within the room, suite or space in which it is located when the concentration of airborne carbon monoxide exceeds a pre-determined level and duration.
Open OBC Div. A 1.4.1.2.(1) in the code viewer
OBC Div. B 6.9.3.1. Application
(1)Article 6.9.3.2. applies to every building that
(a)contains a residential occupancy, a care occupancy with individual suites, or a care occupancy containing sleeping rooms not within a suite, and contains a fuel-burning appliance or a storage garage, or
(b)contains a residential occupancy and is served by a forced-air fuel-burning appliance not contained within the building.
(2)Articles 6.9.3.3. and 6.9.3.4. apply to every building.
Open OBC Div. B 6.9.3.1. in the code viewer
OBC Div. B 6.9.3.2. Location of Carbon Monoxide Alarms
(1)A carbon monoxide alarm shall be installed in a suite of residential occupancy or care occupancy where
(a)a fuel-burning appliance or a flue is installed in the suite,
(b)a forced-air fuel-burning appliance provides heated air directly to the suite,
(c)a fuel-burning appliance or a flue is located in a room, suite or area that shares a common wall or floor or ceiling assembly with the suite, or
(d)a storage garage shares a common wall or floor or ceiling assembly with the suite.
(2)Where a carbon monoxide alarm is required by Sentence (1) to be installed in a suite of residential occupancy or care occupancy, other than a suite that consists of a combined living and sleeping area, a carbon monoxide alarm shall be installed
(a)adjacent to each sleeping room in the suite, and
(b)on each storey without a sleeping room in the suite.
(3)Where a carbon monoxide alarm is required by Sentence (1) to be installed in a suite of residential occupancy or care occupancy that consists of a combined living and sleeping area, a carbon monoxide alarm shall be installed in the combined living and sleeping area.
(4)In addition to the carbon monoxide alarms required to be installed in a suite of residential occupancy or care occupancy in accordance with Sentence (2), a carbon monoxide alarm shall be installed in each sleeping room within the suite where the sleeping room
(a)contains a fuel-burning appliance or a flue, or
(b)shares a common wall or floor or ceiling assembly with
(i)a room, suite or area that is located outside the suite and contains a fuel-burning appliance or a flue, or
(ii)a storage garage.
(5)Carbon monoxide alarms shall be installed in public corridors serving suites of residential occupancy where the corridor is directly heated by a forced-air fuel-burning appliance.
(6)Where carbon monoxide alarms are required by Sentence (5) to be installed in a public corridor, the carbon monoxide alarms shall be installed such that
(a)there is at least one carbon monoxide alarm in each portion of a divided corridor, and
(b)each carbon monoxide alarm in an undivided portion of a corridor is spaced not more than 25 m apart.
Open OBC Div. B 6.9.3.2. in the code viewer
OBC Div. B 6.9.3.3. Location of Carbon Monoxide Alarms in All Buildings
(1)A carbon monoxide alarm shall be installed in service rooms or other areas of a building where the service room or other area
(a)contains a fuel-burning appliance used for building services or laundry drying equipment, and
(b)is not located within a suite of residential occupancy.
Open OBC Div. B 6.9.3.3. in the code viewer
OBC Div. B 6.9.3.4. Installation and Conformance to Standards
(1)The carbon monoxide alarms required by Articles 6.9.3.2. and 6.9.3.3. shall
(a)except as permitted in Sentence (2), be permanently connected to an electrical circuit and shall have no disconnect switch between the overcurrent device and the carbon monoxide alarm,
(b)in case the regular power supply to the carbon monoxide alarm is interrupted, be provided with a battery as an alternative power source that can continue to provide power to the carbon monoxide alarm for a period of not less than 8 h in the standby condition, followed by the operation of the carbon monoxide alarm for an alarm signal for at least 12 h,
(c)be wired so that
(i)activation of one carbon monoxide alarm within a suite of residential occupancy will activate all carbon monoxide alarms within the suite, and
(ii)activation of one carbon monoxide alarm located in a public corridor serving suites of residential occupancy will activate all carbon monoxide alarms within the corridor,
(d)be audible within sleeping rooms when the intervening doors are closed, where located adjacent to a sleeping room in a suite of residential occupancy, and
(e)conform to
(i)CAN/CSA-6.19, "Residential Carbon Monoxide Alarming Devices", or
(ii)UL 2034, "Single and Multiple Station Carbon Monoxide Alarms".
(2)Where the building is not supplied with electrical power, carbon monoxide alarms are permitted to be battery operated.
(3)Except as permitted in Sentence (4), the carbon monoxide alarms required by Articles 6.9.4.2. and 6.9.4.3. shall have a visual signalling component conforming to the requirements in 18.5.3. (Light, Color and Pulse Characteristics) of NFPA 72, "National Fire Alarm and Signaling Code".
(4)Where the building is not supplied with electrical power, carbon monoxide alarms need not have a visual signalling component.
(5)The luminous intensity for visual signalling components required by Sentence (3) that are installed in sleeping rooms or combined living and sleeping areas shall be a minimum of 175 cd.
(6)The visual signalling component required by Sentence (3) need not
(a)be integrated with the carbon monoxide alarm provided it is interconnected to it,
(b)be on battery backup, or
(c)have synchronized flash rates, when installed in a dwelling unit.
(7)The carbon monoxide alarms required by Articles 6.9.3.2. and 6.9.3.3. shall be installed
(a)at the manufacturer's recommended height, or
(b)in the absence of specific instructions, on or near the ceiling.
Open OBC Div. B 6.9.3.4. in the code viewer
OBC Div. B 5.6.2.3. Solar Collector Systems
(1)A solar collector system is permitted to be installed above roofing materials conforming to Table 5.9.1.1.
Open OBC Div. B 5.6.2.3. in the code viewer
OBC Div. B 3.1.5.28. Combustible Solar Collector Systems
(1)A combustible solar collector system is permitted to be installed above the roof of a building required to be of noncombustible construction.
Open OBC Div. B 3.1.5.28. in the code viewer
OBC Div. B 7.2.10.13. Solar Domestic Hot Water
(1)Equipment for solar heating of potable water shall conform to CAN/CSA-F379 SERIES, "Packaged solar domestic hot water systems (liquid-to-liquid heat transfer)."
Open OBC Div. B 7.2.10.13. in the code viewer
OBC Div. B 7.6.1.8. Solar Domestic Hot Water Systems
(1)Systems for solar heating of potable water shall be installed in conformance with CAN/CSA-F383, "Installation of packaged solar domestic hot water systems."
Open OBC Div. B 7.6.1.8. in the code viewer
OBC Div. B 7.2.11.3. Tracer Wire
(1)Except as provided in Sentence (2), every non-metallic water service pipe or fire service main shall have attached to
(a)a 14 gauge TW solid copper light coloured plastic coated tracer wire, or
(b)a 12 gauge copper clad steel light coloured plastic coated tracer wire.
(2)Where a water service pipe or fire service main is detectable without the tracer wire referenced in Sentence (1), the tracer wire may be omitted.
Open OBC Div. B 7.2.11.3. in the code viewer
OBC Div. B 7.1.3.1. Lighting and Ventilation Requirements
(1)Plumbing fixtures shall not be installed in a room that is not lighted and ventilated in accordance with the appropriate requirements in Parts 3, 6 and 9.
Open OBC Div. B 7.1.3.1. in the code viewer