CAN/CSA-P.7-10 (R2015)

Preface

This is the second edition of CSA P.7, Test method for measuring energy loss of gas-fired instantaneous water heaters. It supersedes the previous edition, published in 1998 under the title Testing Method for Measuring Energy Loss of Gas-Fired Instantaneous Water Heaters.

This Standard provides a method for measuring energy loss of gas-fired instantaneous water heaters, and is intended to serve as a stand-alone document for use in Canadian jurisdictions. This test method is generally consistent with the US Department of Energy criteria for gas-fired instantaneous water heaters as specified in the Code of Federal Regulations.

The major changes from the previous edition are as follows:

(a) This Standard has been renumbered to comply with current CSA format.

(b) This Standard is written in both SI (metric) and yard-pound (imperial) units.

(c) The scope of this Standard has been revised to include water heaters with heat inputs less than or equal to 73.2 kW (250 000 Btu/h).

(d) The types of appliances covered by this Standard have been clarified.

(e) A list of symbols used in the Standard has been added.

(f) The configuration for testing has been revised to show the piping arrangements for instantaneous water heaters equipped with bottom or side connections.

(g) Power input determinations have been revised.

(h) A test method for measuring electrical power and standby power consumption has been added.

(i) The first hour rating test has been replaced with a L/min (gpm) rating test.

(j) Maximum flow rates through an instantaneous water heater for Canadian summer and winter conditions have been added (see Annex B).

(k) A procedure for switching between maximum and minimum flow rates when testing water heaters with variable inputs has been added (see Annex D).

(l) A sampling plan for compliance, verification, and rating of instantaneous water heaters has been added (see Annex C).

(m) Minimum and high-efficiency performance levels for gas-fired instantaneous water heaters have been added (see Annex A).

This Standard was prepared by the Subcommittee on Efficiency of Gas-Fired Instantaneous Water Heaters, under the jurisdiction of the Technical Committee on Gas Appliances and Related Accessories and the Strategic Steering Committee on Fuel-Burning Equipment, 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 procedures for 24 h simulated-use testing of gas-fired instantaneous water heaters. This Standard also provides calculations for the determination of

(a) the maximum L/min (gpm) rating;

(b) recovery efficiency (thermal efficiency);

(c) daily water-heating energy consumption;

(d) energy factor; and

(e) annual energy consumption.

1.2

This Standard applies to gas-fired instantaneous water heaters that

(a) initiate heating based on water flow;

(b) use a fixed or variable input;

(c) have a specified storage capacity less than 7.57 L (2 US gal);

(d) have a maximum input rating between 14.7 and 73.2 kW (50 000 and 250 000 Btu/h); and

(e) are designed to deliver water at a controlled temperature of less than 82 C (180 F).

1.3

The tests specified in this Standard provide a method of comparing performance and efficiency for all applications. The performance ratings are intended to be representative of residential applications.

1.4

In CSA Standards, 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.

1.5

The mandatory requirements of this Standard are those expressed in SI (metric) units. The units given in parentheses are approximate and are for information purposes only.

Note: The values in parentheses are from the US Code of Federal Regulations, Title 10, Part 430, Subpart B, Appendix E.

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