GB 26969-2025Minimum allowable values of energy efficiency and energy efficiency grades for domestic solar water heating systems (English PDF)

Foreword

This document is in accordance with the provisions of GB/T 1.1-2020 "Guidelines for standardization work Part

1.Structure and drafting rules for standardization documents" Drafting. This document replaces GB 26969-2011 "Limited values of energy efficiency and energy efficiency grades for domestic solar water heating systems" and GB 26969-2011 In addition to structural adjustments and editorial changes, the main technical changes are as follows:

a) The energy saving evaluation value has been deleted (see

5.4 of the.2011 edition);

b) The basic requirements (see

5.1 of the.2011 edition) have been deleted;

c) Deleted the inspection rules (see Chapter 7 of the.2011 edition);

d) Changed the energy efficiency rating values for compact domestic solar water heating systems (see Table 1, Table 1 of the.2011 edition);

e) Changed the energy efficiency rating values for split indirect (split double circuit) domestic solar water heating systems (see Table 2, Table 3 of the.2011 edition);

f) Changed the energy efficiency rating values for split direct (split single circuit) domestic solar water heating systems (see Table 3, Table 2 of the.2011 edition);

g) Changed the energy efficiency rating values for domestic solar water heating systems (see Table 4, Table 4 of the.2011 edition);

h) Added energy efficiency rating values for domestic solar water heating systems (see Table 5);

i) Added the requirements for energy efficiency limit values of domestic solar water heating systems for heating (see Chapter 5);

j) The value of a in the energy efficiency coefficient calculation formula has been changed (see 6.2, Chapter 4 of the.2011 edition). Please note that some of the contents of this document may involve patents. The issuing organization of this document does not assume the responsibility for identifying patents. This document is proposed and coordinated by the National Standardization Administration. This document was first published in.2011 and this is the first revision. Energy efficiency limit values for domestic solar water heating systems and energy efficiency rating

1 Scope

GB 26969-2025 is the Chinese national standard on minimum allowable values of energy efficiency and energy efficiency grades for domestic solar water heating systems, in the field of energy and heat transfer engineering. It carries no /T suffix, which in the Chinese system means compliance is mandatory: a product or a practice within its scope has to meet it to be lawfully made, sold or carried out in China. It was issued on 1 August 2025 by the State Administration for Market Regulation; Standardization Administration of China, and has been in force since 1 August 2026. Classification: ICS 27.010, CCS F01. This page is published from the official record of the standard held by the Chinese standards administration: the identification, the dates, the classification and the issuing body are taken from there. The clause text, the tables and the numeric limits are in the document itself, which is delivered complete in English translation.

This document specifies the energy efficiency ratings, technical requirements, testing and calculation methods for domestic solar water heating systems. This document applies to solar water heating systems with a water storage tank volume not exceeding 0.6m3.

2 Normative references

The contents of the following documents constitute the essential clauses of this document through normative references in this document. For referenced documents without a date, only the version corresponding to that date applies to this document; for referenced documents without a date, the latest version (including all amendments) applies to This document.

GB 3100 International System of Units and its Application

GB/T 12936 Terminology for solar thermal utilization

GB/T 18708 Test method for thermal performance of domestic solar water heating systems

GB/T 19141 Technical requirements for domestic solar water heating systems

3 Terms and Definitions

The terms and definitions defined in GB 3100, GB/T 12936, GB/T 18708 and GB/T 19141 and the following terms and definitions apply to this document.

3.1 system;CTP Under the test conditions specified in the standard, the ratio of the measured value of daily heat use of domestic solar water heating system to the value specified in the standard and the average heat The comprehensive coefficient of the ratio of the measured value of the loss factor to the value specified in the standard.

3.2 waterheating system The minimum energy efficiency coefficient allowed for domestic solar water heating systems under the test conditions specified in the standard.

3.3 A grading method to indicate the energy efficiency of domestic solar water heating systems, divided into levels 1, 2 and 3, with level 1 indicating the highest energy efficiency.

4 Energy efficiency levels

The energy efficiency levels of domestic solar water heating systems are divided into three levels, and the energy efficiency coefficients of each level should comply with the provisions of Tables 1 to 5.