CSA A440.2:22/A440.3:22

Preface 

This is the eighth edition of CSA A440.2/CSA A440.3, Fenestration energy performance/User guide to CSA A440.2:22, Fenestration energy performance. It supersedes the previous editions published in 2019, 2014, and 2009 under the title Fenestration energy performance/User guide to CSA A440.2 and in 2004, 1998, 1993, and 1991 under the title Energy performance of windows and other fenestration systems (and associated user guides). The major changes to this edition include revisions to the condensation section as follows: 

• the Temperature Index (I) has been updated and the Condensation Index (CI) has been added; 

• the Temperature Index (I) is obtained through measurement and the Condensation Index (CI) is obtained through modelling; and 

• the thermocouple placement figures have been updated. CSA A440.2 applies to the determination of energy performance properties for a variety of fenestration systems, including fixed windows, operable windows, sliding glass doors, hinged doors, skylights with flat glazings, and curtain walls. It includes the following energy performance properties, which are applicable to all building types (residential, commercial, and other): 

• overall coefficient of heat transfer (U-factor); 

• solar heat gain coefficient (SHGC); and 

• visible transmittance (VT).

These properties can be evaluated using either computer simulation or measurement. In addition, CSA A440.2 provides a means for determining a comparative Energy Rating (ER) for fixed and operable windows, sliding doors, and hinged doors to be used in low-rise residential housing. The ER combines the U-factor, SHGC, and heat losses resulting from air leakage into a single rating that allows the energy performance of fixed and operable windows, sliding doors, and hinged doors to be compared over an average heating season. Assumptions have been made about the size of the fixed and operable windows, sliding doors, and hinged doors in order to develop the ER. Annex B provides some information on how climate change can affect fenestration product design and application. CSA A440.3, the user guide to CSA A440.2, has been prepared to explain the content and use of CSA A440.2. CSA A440.3 allows the knowledgeable user to develop specific energy performance properties that apply to fenestration systems of different sizes in specific geographic locations and orientations. CSA A440.3 is divided into three parts. In Section I, the energy performance of fenestration systems is discussed in general terms to provide an overview of the issues that should be considered in the selection of fenestration systems. Section I also explains some of the content of CSA A440.2. In Section II, technical explanations are provided for specific clauses of CSA A440.2. In Section III, the concepts of Specific Energy Rating (ERS) and Energy Rating for the cooling season (ERC) are explained for more advanced users. CSA A440.2 is considered suitable for use for conformity assessment within the stated scope of the Standard. CSA acknowledges that the development of these Standards was made possible, in part, by the financial support of Natural Resources Canada (NRCan). This Standard was prepared by the Subcommittee on Energy Evaluation of Windows, under the jurisdiction of the Technical Committee on Performance Standards for Windows and the Strategic Steering Committee on Construction and Civil Infrastructure, 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.

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CSA A440.2:22 - Fenestration energy performance 

Scope 

1.1 General This Standard applies to a) fenestration systems covered by AAMA/WDMA/CSA 101/I.S.2/A440, including i) vertically sliding windows; ii) horizontally sliding windows; iii) dual-action windows; iv) casement windows, both fixed and operable; v) projecting (awning/hopper) windows; vi) fixed windows; vii) sidelites; viii) transom windows; ix) sliding doors; x) side-hinged doors; xi) dual-action side-hinged doors; xii) architectural terrace doors; xiii) unit skylights and roof windows; xiv) greenhouse or garden windows; and xv) tubular daylighting devices; b) curtain walls, window walls, and storefront; and c) garage (vehicular access/rolling) doors. Note: Unless otherwise specified, the term "fenestration system" is used to apply to all products listed in Clause 1.1. 

1.2 Application This Standard specifies both measurement and computer simulation methods for establishing the following fenestration system properties for both residential and commercial applications: a) overall coefficient of heat transfer (U-factor); b) solar heat gain coefficient (SHGC); c) visible transmittance (VT); and d) Temperature Index (I) and Condensation Index (CI). Note: The fenestration properties established in accordance with this Standard are for specific indoor and outdoor conditions and will vary slightly under actual conditions. The values obtained by the methods specified in this Standard are considered to provide an acceptable basis for comparing performance in use. 

1.3 Energy Rating (ER) 1.3.1 This Standard specifies a method for determining an energy performance rating for vertical fenestration systems, under heating conditions, for use in low-rise residential applications. The Energy Rating (ER) includes factors for a) solar heat gain; b) heat loss by conduction, radiation, and convection; and c) heat loss by air leakage. 1.3.2 The ER allows for a comparison of different fenestration systems on the basis of their effect on the energy supplied annually by the heating system. The ER calculation assumes vertical installation in low-rise residential buildings and is based on average conditions for a) incident solar radiation on fenestration systems facing the four cardinal compass directions (north, east, south, and west); and b) representative climate zones in Canada. 1.3.3 The ER should not be used to rate a) any sloped glazing (residential or commercial); or b) fenestration products that will be installed in commercial, industrial, or high-rise residential buildings. 

1.4 A440.3 general information CSA A440.3 is a user guide to this Standard. It provides guidance on determining a) a specific Energy Rating (ERS) for particular locations, orientations, and vertical fenestration system sizes; and b) an ER for residential cooling (ERC). 

1.5 Annex B general information Annex B introduces the issue of climate change and its associated effects on fenestration in buildings. It is anticipated that fenestration designers will need to incorporate changes in climate loads resulting from climate change into fenestration product design. It is also anticipated that adjustments will need to be made to installation detailing. Annex B provides some information on these topics for consideration by building design professionals, authorities having jurisdiction, and installers. As information on climate change evolves, so too will the requirements of this Standard. 

1.6 Exceptions This Standard does not apply to a) fixed glazing cast into precast concrete panels; b) revolving doors; c) doors intended for indoor use; d) storm doors; and e) glazed architectural structures. Note: While these products have not been considered in the development of this Standard, simulation procedures given in the Standard may be used to evaluate the U-factor and the SHGC of these products. This Standard does not address the retention of thermal and optical properties and airtightness by fenes