Preface  

This is the fifth edition of CSA C746, Energy performance rating for large and single packaged vertical air conditioners and heat pumps . It supersedes the previous editions published in 2017 and in 2006, and previous editions published in 1998 and 1993 under the title Performance Standard for Rating Large Air Conditioners and Heat Pumps.  The following are the major changes to this edition:  a) updates to requirements in reference to the most recent editions of AHRI 340/360, AHRI 365, and AHRI 390; and  b) updates to efficiency requirements to align with ANSI/ASHRAE/IES 90.1 and updated requirements by the U.S. Department of Energy and Natural Resources Canada.  This Standard is considered suitable for use for conformity assessment within the stated scope of the Standard.  CSA Group acknowledges that the development of this Standard was made possible, in part, by the financial support of Natural Resources Canada (NRCan) and Independent Electricity System Operator (IESO).  This Standard was prepared by the Subcommittee on Energy Performance Rating for Large and Single Packaged Vertical Air Conditioners and Heat Pumps, under the jurisdiction of the Technical Committee on Heating, Ventilation, Air-Conditioning, and Refrigeration and the Strategic Steering Committee on Performance, Energy Efficiency, and Renewables, and has been formally approved by the Technical Committee.  This Standard has been developed in compliance with Standards Council of Canada requirements for National Standards of Canada. It has been published as a National Standard of Canada by CSA Group. 

Scope  

1.1 Inclusions  

This Standard applies to the following electrically driven, mechanical, vapour compression-type systems:  a) factory-made commercial and industrial unitary air-cooled air conditioners and heat pumps rated above 19 kW (65 000 Btu/h) cooling capacity at standard rating conditions for both single- and three-phase electrical power supplies;  b) factory-made commercial and industrial unitary water and evaporative-cooled air conditioners;  c) all sizes of single packaged vertical air conditioners and heat pumps and air-conditioning condensing units; and  d) commercial air-cooled, water-cooled, and evaporative-cooled split-system condensing units rated above 40 kW (135,000 Btu/h).  Notes:  1) See Tables 1 to 3 for classifications of air conditioners, heat pumps, and air-conditioning condensing units.  2) Unitary air-cooled air conditioners rated below 19 kW (65 000 Btu/h) are covered by CSA C656.  3) Commercial split systems rated above or equal to 19 kW (65 000 Btu/h) and with a cooling capacity less than 40 kW (135 000 Btu/h) are rated with the indoor unit per the requirements of Note 1.  

1.2 Methods for rating  

This Standard provides methods for rating the following factory-designed and prefabricated products:  a) air-conditioning or heat pump equipment above 19 kW (65 000 Btu/h) cooling capacity that is covered by AHRI 340/360;  b) water-cooled air-conditioning equipment;  c) evaporative-cooled air-conditioning equipment;  d) single packaged vertical air-conditioning equipment; and  e) commercial split systems above 40 kW (135 000 Btu/h).  It also specifies minimum energy efficiency levels as defined by referenced standards; however, final levels for compliance will depend on NRCan and provincial adoption regulations.  

1.3 Terminology  

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.  

1.4 Dual measurements  

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.  Note: Minimum efficiency metrics for energy efficiency ratios (EER) and integrated energy efficiency ratios (IEER) are in I-P units of Btu/w to harmonize with U.S. requirements.