Last updated
Values this chapter turns on
- outdoor appliance to the property line
- 1,200 mm
- outdoor appliance to the property line
- pipe temperature up to which no clearance is needed
- 95°C
- pipe temperature up to which no clearance is needed
- CO alarm battery standby before 12 h of alarm
- 8 h
- CO alarm battery standby before 12 h of alarm
- visual CO alarm intensity in sleeping areas
- 175 cd
- visual CO alarm intensity in sleeping areas
This chapter covers Section 6.4. (heating appliances, unit heaters, radiators and convectors) and Section 6.9. (fire safety: fire dampers, smoke detectors in air handling systems, exhaust ducts, carbon monoxide alarms and ash bins). Article 6.4.1.1. (location of appliances) and Articles 6.9.1.2. and 6.9.1.3. (hazardous gases and commercial cooking) are excluded from the syllabus.
Heating appliances, unit heaters, radiators and convectors
Appliances installed outside a building must be OBC Div. B 6.4.1.2.OBC Div. B 6.4.1.2. Appliances Installed Outside the Building(1) Fuel-fired appliances installed outside a building shall be (a) designed and constructed for outdoor use, (b) installed not less than 1,200 mm from the property line, measured horizontally, and (c) installed not less than 3 m from an adjacent wall of the same building when such wall contains an opening or openings…:
| Requirement | Value |
|---|---|
| Design | Designed and constructed for outdoor use |
| Distance to property line | Not less than 1,200 mm, measured horizontally |
| Distance to a wall of the same building with openings | Not less than 3 m, where the wall has openings within 3 storeys above and 5 m horizontally of the appliance |
| Exception to the 3 m rule | The openings are protected by a closure with a 45 min fire-protection rating, or by wired glass |
Unit heaters using steam or hot water must keep clearances to combustibles from the pipe clearance table OBC Div. B 6.4.2.1.OBC Div. B 6.4.2.1. Clearances(1) Every unit heater using either steam or hot water as the heating medium shall be installed such that the clearances between the appliance and adjacent combustible material conform to Table 6.7.1.2..
Radiators and convectors (steam or hot water) need a noncombustible lining or backing if located in a recess or concealed space, or attached to a wall of combustible or encapsulated mass timber construction, and must meet the same clearance table OBC Div. B 6.4.3.1.OBC Div. B 6.4.3.1. Lining or Backing(1) A noncombustible lining or backing shall be provided for every steam or hot water radiator and convector (a) located in a recess or concealed space, or (b) attached to the face of a wall of combustible construction or encapsulated mass timber construction. (2) Every steam or hot water radiator and convector shall….
The clearance table is short OBC Div. B Table 6.7.1.2.OBC Div. B Table 6.7.1.2. Clearance Between Steam or Hot Water Pipes and Combustible Material — Forming Part of Article 6.4.2.1., Sentence 6.4.3.1.(2) and Article 6.7.1.2.Table 6.7.1.2. Clearance Between Steam or Hot Water Pipes and Combustible Material — Forming Part of Article 6.4.2.1., Sentence 6.4.3.1.(2) and Article 6.7.1.2. Steam or Water Temperature, °C | Minimum Clearance, mm Up to 95 | No clearance Above 95 to 120 | 15 mm Above 120 | 25 mm:
| Steam or water temperature | Minimum clearance to combustibles |
|---|---|
| Up to 95°C | None |
| Above 95°C to 120°C | 15 mm |
| Above 120°C | 25 mm |
Part 9 has an identical table for houses (Table 9.33.8.3.).
Fire safety: dampers and ductwork
The fire safety characteristics of HVAC systems must comply with Subsection 3.6.5. OBC Div. B 6.9.1.1.OBC Div. B 6.9.1.1. Fire Safety Requirements(1) The fire safety characteristics of heating, ventilating and air-conditioning systems shall comply with Subsection 3.6.5. (2) Characteristics referred to in Sentence (1) include but are not limited to (a) use of combustible materials in duct systems, (b) flame-spread ratings and smoke-developed ratings of duct and…. The code lists what that covers: combustible materials in ducts, flame-spread and smoke-developed ratings of duct and pipe materials and coverings, equipment location relative to property lines, and fire dampers and fire stop flaps.
Short pointer Articles follow:
| Article | Points to |
|---|---|
| 6.9.2.1.OBC Div. B 6.9.2.1. Fire Dampers(1) Fire dampers shall conform to Article 3.1.8.10. Fire dampers | Article 3.1.8.10. |
| 6.9.2.2.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. Smoke detectors | Air handling systems incorporate smoke detectors as Article 3.2.4.12. requires |
| 6.9.2.3.OBC Div. B 6.9.2.3. Exhaust Ducts and Outlets(1) Where an exhaust duct system is used for smoke removal in a high building, the requirements of Article 3.2.6.6. shall apply. (2) Where exhaust duct systems from more than one fire compartment are connected to an exhaust duct in a vertical service space, the requirements of Article 3.6.3.4. shall apply. Exhaust ducts | Smoke removal in high buildings (3.2.6.6.); exhaust ducts from more than one fire compartment into a vertical service space (3.6.3.4.) |
| 6.9.2.4.OBC Div. B 6.9.2.4. Ducts in Exits(1) Where ducts penetrate fire separations separating exits from the remainder of the building, they shall be in accordance with Article 3.4.4.4. (2) Duct penetration of fire separations separating exits from the remainder of the building is permitted if the duct (a) is designed for the purposes of Subsection 3.2.6.… Ducts in exits | Penetrations follow 3.4.4.4.; allowed only for Subsection 3.2.6. purposes or a duct serving only the exit from a dedicated rooftop makeup unit |
Carbon monoxide alarms and ash storage
Part 6 has its own CO alarm Subsection, which mirrors 9.32.3.9. to 9.32.3.9C. for Part 9.
When it applies OBC Div. B 6.9.3.1.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…. The location rules apply to a building that contains a residential occupancy or certain care occupancies and also contains a fuel-burning appliance or a storage garage, or a residential building served by a forced-air fuel-burning appliance outside the building. The service-room rule and the installation rules apply to every building.
Where alarms go OBC Div. B 6.9.3.2.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…. A suite needs CO protection if it has a fuel-burning appliance or flue, gets heated air directly from a forced-air fuel-burning appliance, or shares a wall, floor or ceiling with a room or area containing an appliance or flue, or with a storage garage. Inside that suite, alarms go adjacent to each sleeping room and on each storey without a sleeping room; bachelor-type suites get one in the combined living and sleeping area. Extra alarms go inside sleeping rooms that contain an appliance or flue or share an assembly with one outside the suite or with a garage. Public corridors heated directly by a forced-air fuel-burning appliance need alarms, at least one per divided portion and spaced not more than 25 m apart.
Service rooms with a fuel-burning appliance for building services or laundry drying equipment, outside a residential suite, need an alarm OBC Div. B 6.9.3.3.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..
Installation OBC Div. B 6.9.3.4.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…:
| Feature | Requirement |
|---|---|
| Power | Permanently connected, no disconnect switch between the overcurrent device and the alarm |
| Battery backup | 8 h standby, then 12 h of alarm |
| Interconnection | All alarms in a suite; all alarms in a public corridor |
| Audibility | Audible in sleeping rooms with doors closed |
| Standard | CAN/CSA-6.19 or UL 2034 |
| Visual signal | NFPA 72 characteristics; at least 175 cd in sleeping areas |
| Mounting height | Manufacturer's recommended height, or on or near the ceiling |
| No electrical power in building | Battery operation allowed, no visual component needed |
Ash storage bins must be noncombustible, and every opening needs a tight-fitting metal door with a metal frame fastened to the bin OBC Div. B 6.9.4.1.OBC Div. B 6.9.4.1. Ash Storage Bins(1) Every ash storage bin shall be constructed of noncombustible material. (2) Every opening in an ash storage bin shall be protected by a tight-fitting metal door with metal frame securely fastened to the bin.. Fireplaces conform to Section 9.22. OBC Div. B 6.9.4.2.OBC Div. B 6.9.4.2. Fireplaces(1) Fireplaces shall conform to the requirements of Section 9.22..
Common traps
- Using 1.2 m from the property line as a wall clearance. The wall rule is 3 m.
- Reading the clearance table as "15 mm at 95°C". At exactly 95°C no clearance is needed.
- Forgetting the battery backup numbers differ from smoke alarms: CO alarms need 8 h standby plus 12 h alarm; smoke alarms need 7 days plus 4 minutes.
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.
- Heating appliances, unit heaters, radiators and convectors
A rooftop-style gas unit is to be placed beside a wall with a window 2 m to the side and one storey above.
- Fire safety: dampers and ductwork
The fire safety characteristics of HVAC systems must comply with Subsection 3.6.5.. The code lists what that covers: combustible materials in ducts, flame-spread and…
- Carbon monoxide alarms and ash storage
Part 6 has its own CO alarm Subsection, which mirrors 9.32.3.9. to 9.32.3.9C. for Part 9.
Usual exam traps
- Using 1.2 m from the property line as a wall clearance. The wall rule is 3 m.
- Reading the clearance table as "15 mm at 95°C". At exactly 95°C no clearance is needed.
- Forgetting the battery backup numbers differ from smoke alarms: CO alarms need 8 h standby plus 12 h alarm; smoke alarms need 7 days plus 4 minutes.
Practice this chapter
Questions on Part 6: heating appliances and fire safety systems, in the exam format, every answer explained and cited to its article. Sign in to start; a free account gets the free questions.
Code cited in this chapter
Based on the official 2024 Building Code Compendium on ontario.ca.
© King's Printer for Ontario, 2024. Reproduced with permission.
OBC Div. B 6.4.1.2. Appliances Installed Outside the Building
Open OBC Div. B 6.4.1.2. in the code viewer(1)Fuel-fired appliances installed outside a building shall be
(a)designed and constructed for outdoor use,
(b)installed not less than 1,200 mm from the property line, measured horizontally, and
(c)installed not less than 3 m from an adjacent wall of the same building when such wall contains an opening or openings within 3 storeys above and 5 m horizontally from the appliance, unless such openings are protected by a closure assembly having a 45 min fire-protection rating determined in conformance with Article 3.1.8.4., or by wired glass conforming to Article 3.1.8.14.
OBC Div. B 6.4.2.1. Clearances
Open OBC Div. B 6.4.2.1. in the code viewer(1)Every unit heater using either steam or hot water as the heating medium shall be installed such that the clearances between the appliance and adjacent combustible material conform to Table 6.7.1.2.
OBC Div. B 6.4.3.1. Lining or Backing
Open OBC Div. B 6.4.3.1. in the code viewer(1)A noncombustible lining or backing shall be provided for every steam or hot water radiator and convector
(a)located in a recess or concealed space, or
(b)attached to the face of a wall of combustible construction or encapsulated mass timber construction.
(2)Every steam or hot water radiator and convector shall be installed so as to conform to the clearance requirements of Table 6.7.1.2.
OBC Div. B Table 6.7.1.2. Clearance Between Steam or Hot Water Pipes and Combustible Material — Forming Part of Article 6.4.2.1., Sentence 6.4.3.1.(2) and Article 6.7.1.2.
Open OBC Div. B Table 6.7.1.2. in the code viewerTable 6.7.1.2. Clearance Between Steam or Hot Water Pipes and Combustible Material — Forming Part of Article 6.4.2.1., Sentence 6.4.3.1.(2) and Article 6.7.1.2. Steam or Water Temperature, °C | Minimum Clearance, mm Up to 95 | No clearance Above 95 to 120 | 15 mm Above 120 | 25 mm
OBC Div. B 6.9.1.1. Fire Safety Requirements
Open OBC Div. B 6.9.1.1. in the code viewer(1)The fire safety characteristics of heating, ventilating and air-conditioning systems shall comply with Subsection 3.6.5.
(2)Characteristics referred to in Sentence (1) include but are not limited to
(a)use of combustible materials in duct systems,
(b)flame-spread ratings and smoke-developed ratings of duct and pipe materials and coverings,
(c)installation of equipment relative to property lines, and
(d)requirements for fire dampers and fire stop flaps.
OBC Div. B 6.9.2.1. Fire Dampers
Open OBC Div. B 6.9.2.1. in the code viewer(1)Fire dampers shall conform to Article 3.1.8.10.
OBC Div. B 6.9.2.2. Smoke Detectors
Open OBC Div. B 6.9.2.2. in the code viewer(1)Air handling systems shall incorporate smoke detectors where and as required by Article 3.2.4.12.
OBC Div. B 6.9.2.3. Exhaust Ducts and Outlets
Open OBC Div. B 6.9.2.3. in the code viewer(1)Where an exhaust duct system is used for smoke removal in a high building, the requirements of Article 3.2.6.6. shall apply.
(2)Where exhaust duct systems from more than one fire compartment are connected to an exhaust duct in a vertical service space, the requirements of Article 3.6.3.4. shall apply.
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OBC Div. B 6.9.2.4. Ducts in Exits
Open OBC Div. B 6.9.2.4. in the code viewer(1)Where ducts penetrate fire separations separating exits from the remainder of the building, they shall be in accordance with Article 3.4.4.4.
(2)Duct penetration of fire separations separating exits from the remainder of the building is permitted if the duct
(a)is designed for the purposes of Subsection 3.2.6., or
(b)only serves the exit from a dedicated rooftop air make-up unit.
OBC Div. B 6.9.3.1. Application
Open OBC Div. B 6.9.3.1. in the code viewer(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.
OBC Div. B 6.9.3.2. Location of Carbon Monoxide Alarms
Open OBC Div. B 6.9.3.2. in the code viewer(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.
OBC Div. B 6.9.3.3. Location of Carbon Monoxide Alarms in All Buildings
Open OBC Div. B 6.9.3.3. in the code viewer(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.
OBC Div. B 6.9.3.4. Installation and Conformance to Standards
Open OBC Div. B 6.9.3.4. in the code viewer(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.
OBC Div. B 6.9.4.1. Ash Storage Bins
Open OBC Div. B 6.9.4.1. in the code viewer(1)Every ash storage bin shall be constructed of noncombustible material.
(2)Every opening in an ash storage bin shall be protected by a tight-fitting metal door with metal frame securely fastened to the bin.
OBC Div. B 6.9.4.2. Fireplaces
Open OBC Div. B 6.9.4.2. in the code viewer(1)Fireplaces shall conform to the requirements of Section 9.22.