The OMAFRA TSSA Working Group hired a consultant to address this issue and subsequently developed Code clauses specifically to address the needs of the livestock and poultry industry.
The following document applies only to heaters that vent products of combustion inside the barn. If the heaters are presently vented outside of the barn or if venting is being changed to vent outside then these barns already meet the Gas Code.
From a Fuels Safety Program Advisory
The most recent amendment to the Gaseous Fuels Code Adoption Document (FS-212-14, dated August 1, 2014, effective October 1, 2014) includes specific requirements for natural gas or propane heating appliances installed in livestock and poultry barns that vent their products of combustion into the barn space (clause 7.36).
These requirements include that the ventilation system designer (who must be licensed as a professional engineer in Ontario, pursuant to the Professional Engineers Act) must verify the following two calculations and prominently display this information in the entrance area of each barn:
1) Minimum ventilation rate of the barn (mechanical or natural ventilation) when the heaters are operating is not less than 300 CFM / 100,000 BTUH (0.003 CFM/BTUH) of heaters input [clause 7.36.1(c)].
2) Maximum input of the heating appliances does not exceed 20 BTUH/FT3 of the space in which the appliance is located
Source: OntarioPork