Gas Fired Heaters Used Indoors

23 February 2017

Reference #:  IB-GA 2017-01

Topic

This information bulletin provides guidance in the proper use of gas fired heaters used indoors or under covered areas, such as tents and awnings.

Important Information

Gas fired heaters are appliances that generate radiant, infrared, and/or convection heat. All gas appliances must be certified, by a certification agency accredited by the Standards Council of Canada, to a standard applicable to their intended use, such as indoors and/or outdoors. 

The standard to which outdoor units are certified, defines “outdoor” as a shelter no more inclusive than:

  1. walls on all sides, but with no overhead cover,
  2. a partial enclosure which includes an overhead cover and no more than two side walls which may be paralleled, as in a breezeway, or at right angles to each other, or
  3. a partial enclosure which includes overhead cover and three side walls, as long as 30% or more of the horizontal periphery of the enclosure is permanently open.

A screened wall (bug screen) in considered to be a wall as air flow through a screen is very poor.

Gas fired appliances generate products of combustion when in use and must be vented to the outdoors. Manufacturers may require the heaters used indoors to be electrically interlocked to an exhaust fan with an air-proving switch. The exhaust fan must provide the exhaust flow rate required by the manufacturer.

Propane cylinders are not permitted in a confined space, including enclosed tents.

A certified heater for tents uses a forced air system to transfer heated air into the tent via ducting from an exterior combustion chamber, which exhausts combustion products to open air.

The installation of gas fired appliances including gas supply and electrical supply must adhere to all applicable Codes. Electrical equipment must be certified for the intended purpose. The manufacturer’s installation and usage instructions are a condition of that certification. Any limitations should accompany the product in the form of warnings on a nameplate or within the instructions provided. If in doubt, contact the manufacturer or the certification organization.

Only BCSA licensed contractors shall install gas appliances. All gas fired appliances require an installation permit from BCSA.

Heaters certified for indoor installations must adhere to required minimum clearances of B149.1, 4.13 when installed near a combustible wall or under a combustible ceiling.

Combustible materials are materials that fail to conform to CAN/ULC-S114 requirements for noncombustibility such as wood, compressed paper, plant fibers, or other materials capable of being ignited and burned. Such materials may be considered combustible if they do not conform to CAN/ULC-S114 even if flame proofed, fire retardant treated or plastered.

Additional clearances may be required for glass, painted surfaces, plastics, vinyls and other materials which may be damaged or melted by radiant or convection heat. Manufacturers of these materials should be consulted about temperature limits to prevent damage.

Brad Wyatt
Provincial Safety Manager -Gas

References:
Safety Standards Act
Gas Safety Regulation
Safety Standards General Regulation