CSA F280:12 (R2025)

Description

Preface This is the third edition of CSA F280, Determining the required capacity of residential space heating and cooling appliances . It supersedes the previous edition published in 1990. This Standard provides contractors, equipment manufacturers, building officials, and others involved in residential construction with updated calculation methods for determining the output capacity of all types of applicable residential space heating and cooling appliances to maintain specified indoor environmental conditions in Canadian homes. However, this Standard does not cover the detailed design and installation of residential space heating and cooling systems. Microsoft Excel® spreadsheets are linked to this Standard for calculating heat loss and heat gain associated with all types of common foundations. The spreadsheets can also be used to calculate some of the factors needed for determining air change, infiltration, and air leakage losses of the building. A description of the spreadsheets, along with instructions for accessing them, is provided in Annex F. Instructions for the use of the spreadsheets can also be found within the spreadsheets themselves. Additional changes to this edition include calculations for determining heat loss due to continuous ventilation, air change heat loss for each room, heat gain through transparent and translucent building assemblies, and heat gain adjustments for shading. Annex B provides a commentary on specific clauses in the Standard with additional information on the principles used for the modeling of foundations, air leakage, and windows. Annex B is also intended to outline, where they are not self-evident, the intent of and rationale behind the various requirements of this Standard in order to facilitate understanding and application of those requirements. CSA acknowledges that the development of this Standard was made possible, in part, by the financial support of Natural Resources Canada (NRCan), the Ontario Ministry of Energy, BC Hydro, Manitoba Hydro, and Efficiency Nova Scotia. CSA also wishes to acknowledge the efforts of the Housing, Buildings Communities and Simulation Group (HBCS) of CanmetENERGY Ottawa, a division of the Innovation and Energy Technology Sector (IETS) of Natural Resources Canada for their technical contribution towards the updating of the Standard; and Meteorological Service of Canada, a division of Environment Canada, for providing the weather data in the spreadsheet. The financial contributions from Enbridge Gas Distribution Inc. and Union Gas Limited for the development of the Microsoft Excel® spreadsheets are also acknowledged. Finally, CSA acknowledges the work of Mindscape Innovations Group for finalizing the spreadsheets. Additionally, CSA wishes to acknowledge the financial contribution of Reliance Comfort Ltd. and the Heating, Refrigeration and Air Conditioning Institute of Canada (HRAI) for the preparation of amendments to this Standard. CSA also acknowledges Brian Bradley of Natural Resources Canada, Sustainable Buildings and Communities Group, CanmetENERGY, for his valuable contribution to the development of this Standard and for his evaluation of the spreadsheets during the course of their development. This Standard was prepared by the Technical Committee on Sizing of Residential Heating and Cooling Systems under the jurisdiction of the Strategic Steering Committee on Fuel-Burning Equipment and was 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 provides a calculation method for determining the heat loss and heat gain of buildings (as described in Clause 1.3 below) for the purpose of selecting the appropriate output capacity of a space heating appliance or group of appliances and the output capacity of a cooling appliance or group of appliances. 1.2 This Standard also provides restrictions on selecting the output capacity of a specific space heating or cooling appliance or group of appliances. 1.3 This Standard applies to space heating and cooling appliances for use in housing and small buildings of residential occupancy to which Part 9 of the National Building Code of Canada applies, where the appliances are permanently installed within the dwelling unit they serve. 1.3A This Standard also provides a method for verifying whether a software system produces heat loss and gain results that are representative of the results that would be obtained using a method that exactly follows the calculation method set out in this Standard. 1.3B This Standard applies to software systems which are intended to be used to calculate heat loss and gain of homes according to this Standard. 1.4 This Standard does not deal with detailed design and installation of space heating and cooling systems, but is based on the assumption that the distribution system design complies with good engineering practice as described in the applicable building codes and standards. 1.5 The requirements of this Standard are expressed in SI (metric) units. Note: The requirements in Clause 8 and Annexes G to K are expressed in Imperial and SI (metric) units. 1.6 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; “may” is used to express an option or that which is permissible within the limits of the standard; and “can” is used to express possibility or capability. 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.