ANSI Z83.4-2017 • CSA 3.7-2017

1.1 This Standard applies to newly produced, non-recirculating direct gas-fired heating and forced ventilation appliances, hereinafter referred to as heaters, whose purpose is to address building infiltration, replace building air that is exhausted, offset building conduction heat loss and provide outside air ventilation. All air to the heater is ducted directly from outdoors and the products of combustion generated by the heater are released into the air stream being heated. Heaters covered by this Standard are intended for use in industrial and commercial applications. Heaters covered by this Standard are not intended for use in any area containing sleeping quarters. The installation conforms with local codes, or in the absence of local codes, in accordance with the National Fuel Gas Code, ANSI Z223.1/NFPA 54, or the Natural Gas and Propane Installation Code, CSA B149.1. 1.2 This Standard applies to heaters designed for heated discharge air temperature of 160 °F (71 °C) or less. 1.3 This Standard is intended to cover only complete packaged heaters with integral air moving components, i.e., those which are designed by, cataloged by, and built on a repetitive basis by the manufacturer. 1.4 If a value for measurement as given in this Standard is followed by an equivalent value in other units, the first stated value is to be regarded as the specification. 1.5 Items unique to the U.S.A. are shown in Clause 6. 1.6 Items unique to Canada are shown in Clause 7. 1.7 Clause 2, Reference publications, contains a list of standards specifically referenced in this Standard, and sources from which these referenced standards may be obtained. 1.8 All references to “psi” through this Standard are to be considered gage pressure unless otherwise specified. 1.9 In this Standard, “shall” is used to express a requirement, i.e., a provision that the user shall satisfy in order to comply with the standard; “should” is used to express a recommendation or that which is advised but not required; and “may” is used to express an option or that which is permissible within the limits of the standard. Notes accompanying clauses do not include requirements or alternative requirements; the purpose of a note accompanying a clause is to separate from the text explanatory or informative material. Notes to tables and figures are considered part of the table or figure and may be written as requirements. Annexes are designated normative (mandatory) or informative (non-mandatory) to define their application.