CSA C745:20 (R2025)

Description

Preface This is the fourth edition of CSA C745, Energy efficiency of electric storage tank water heaters and heat pump water heaters . It supersedes the previous editions published in 2003, 2000, and 1995. This Standard provides a standard method for measuring the performance of these water heaters and establishes a minimum acceptable operating efficiency level for electric storage tank water heaters. This Standard has been updated to be compatible with the latest requirements of the United States Department of Energy (DOE) publication 79 FR 40541 published in July 2014. CSA acknowledges that the development of this Standard was made possible, in part, by the financial support of Natural Resources Canada (NRCan), BC Hydro, Manitoba Hydro, Hydro-Québec, Canadian Electricity Association (CEA), and Independent Electricity System Operator (IESO). This Standard is considered suitable for use for conformity assessment within the stated scope of the Standard. This Standard was prepared by the Subcommittee on Water Heaters, under the jurisdiction of the Technical Committee on Residential Equipment 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 This Standard specifies the methods for determining the uniform energy factor for electric storage tank water heaters and heat pump water heaters. 1.2 This Standard a) establishes minimum energy efficiency levels for electric storage tank water heaters and heat pump water heaters; and b) includes advanced test methods for cold climate ratings (see Annex B). 1.3 This Standard applies to a) electric storage tank water heaters i) with volumes of 7.6 to 454 L (2 to 120 US gal); ii) having electric heater elements with power inputs ≤ 12 kW; and iii) designed to heat and store water at a thermostatically controlled temperature equal to or less than 82 °C (180 °F); and b) heat pump water heaters that have i) a maximum current rating of ≤ 24 A (including the compressor and all auxiliary equipment such as fans, pumps, controls, and, if on the same circuit, any resistive elements); ii) a maximum wattage rating ≤ 15 kW; iii) a single-phase maximum voltage of ≤ 250 V; iv) volumes of 7.6 to 454 L (2 to 120 US gal); and v) rated storage volume ≤ 454 L (≤ 120 US gal). 1.4 This Standard does not apply to high-temperature water heaters. 1.5 The tests contained in this Standard are not intended to represent actual efficiencies realized in the field. Instead, these tests provide a standardized method of comparing performance. 1.6 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. 1.7 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.