Preface This is the fourth edition of the Packaged terminal air-conditioners and heat pumps, jointly published by the Air-Conditioning, Heating, and Refrigeration Institute (AHRI 310/380) and CSA Group (CSA C744). It supersedes the previous editions of this joint Standard published in 2014 and 2004 under the title Standard for Packaged Terminal Air-Conditioners and Heat Pumps. This Standard, which applies to factory-manufactured residential, commercial, and industrial packaged terminal air-conditioners and heat pumps, provides requirements for rating, performance, and tests. Separate requirements are provided for Canadian jurisdictions for rating, performance, and tests (see Clause 10). These separate requirements reference CSA Group standards. The publishers of this Standard acknowledge that the development of this Standard was made possible, in part, by the financial support of Natural Resources Canada. Scope 1.1 This Standard applies to factory-manufactured residential, commercial, and industrial packaged terminal air-conditioners and heat pumps as defined in Clause 3. 1.2 This Standard applies to electrically operated vapour-compression refrigeration systems. 1.3 This Standard applies to packaged terminal air-conditioners and heat pumps intended for unducted installation, but may be employed with ductwork having external static resistance up to 25 Pa (0.1 in H2O). 1.4 This Standard does not apply to the following: a) heat-operated air-conditioning/heat pump equipment or room air-conditioners/heat pumps, as defined in CAN/CSA-C368.1; b) water-to-air and brine-to-air heat pumps, as defined in CAN/CSA-C13256-1-01; c) unitary air-conditioners and air-source unitary heat pumps, as defined in CAN/CSA-C656 and ANSI/AHRI 210/240, with capacities less than 19 000 W (65 000 Btu/h); d) commercial and industrial unitary air-conditioners and heat pumps, as defined in CAN/CSA-C746 and ANSI/AHRI 340/360, with capacities of 19 000 W (65 000 Btu/h) or greater; e) commercial and industrial single package vertical air-conditioners and heat pumps, as defined in ANSI/AHRI 390, with capacities of 39 300 W (134 000 Btu/h) or less; and f) units with integral gas-fired heating. 1.5 In this Standard, \"shall\" is used to express a requirement, i.e., a provision that the user is obliged to 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. 1.6 The values given in SI units are the units of record for the purposes of this Standard. The values given in parentheses are for information and comparison only.