Gas Trade: Unit 22 - Venting practices
CSA Group's 2020 Gas Trade materials reference the Red Seal Program's trade outlines for your preparation to become a nationally recognized gasfitter. Please visit the Red Seal Program's website for more details.
The main functions of venting systems are to:
• completely vent the flue gases to the outdoors without spillage into the building;
• effectively vent at a rate that ensures the proper operation of the appliance;
• operate safely in terms of fire; and
• keep the weather out of the building.
All forced-air gas-fired furnaces manufactured or sold in Canada after January 1, 2010, are required to be high-efficiency, condensing-type appliances that are vented into special venting systems (BH vents). However, many existing low- and mid-efficiency furnaces along with currently manufactured and existing water heaters, boilers, and space heaters that operate with natural draft venting systems continue to exist.
Understanding the requirements for proper installation and operation of natural draft venting systems is more important for gas technicians/fitters since they must make crucial decisions regarding the size, location, and type of material for natural draft vents.
The manufacturers of the appliance and vent system largely determine the size, location, and type of material employed in special venting systems found on all high-efficiency condensing appliances and some low- and mid-efficiency appliances. Chapter 2. Vent installation and assembly, Characteristics of vents and their components covers special venting systems, but the primary focus in the rest of this Unit is on natural draft vent systems.
At the end of this unit, you will be able to:
• Describe venting systems;
• Describe vent installation and assembly;
• Describe vent design and installation requirements;
• Size venting systems;
• Describe vent inspection; and
• Locate and size air supplies for equipment with inputs of 400 MBtu/h or less and over 400 MBtu/h.
The 7th Edition of the Training materials are revised to include the following changes:
• Updated to current standards and codes.
• Updated assignment questions and added chapter numbers.
• Assignment questions now included at the end of each chapter.
• New preface with a listing of standards and codes referenced in each module.