The standards set forth herein apply to the fifth edition of the Standard for Gas-Fired Central Furnaces, Z21.47-2006/CSA 2.3-2006 and supersede corresponding standards therein. Following their preparation by the supervising Technical Advisory Group, they were accepted by the American National Standards Institute (ANSI) and the Interprovincial Gas Advisory Council (IGAC), and subsequently approved.
1.1.1 This Standard applies to automatically operating gas-fired central furnaces see Part XI, Definitions, hereinafter referred to as furnaces, for installation in residential, commercial, and industrial structures including furnaces for Direct Vent, Recreational Vehicle, Outdoor, and Manufactured (Mobile) Homes. These furnaces may include a cooling unit. All units shall be constructed entirely of new, unused parts and materials.