N/A
Furnaces, Heaters, and Ovens
Furnaces, heaters, and oven design and safety standards are published by a wide variety of SDOs, including, NFPA, ASSE, ASTM, CSA, and many more. They cover products in many applications and industries, from home water and air heaters, furnaces to meld metals, and conventional ovens for food preparation. Not only product attributes are specified; many documents listed here contain valuable information to prevent accidents when working with hazardous combustible tools and materials, such as the NFPA systems hazards code. The most commonly referred-to product here is the has-powered heater, with many specifications depending on the scope and demands of the heater's performance, from home heaters to industrial heaters, and covers all aspects of safety, installation, and construction.
NFPA 86-2019
NFPA 86 Standard for Ovens and Furnaces, 2019 edition
This standard shall apply to Class A, Class B, Class C, and Class D ovens, dryers, and furnaces; thermal oxidizers; and any other heated systems and related equipment used for processing of materials. The terms ovens, dryers, and furnaces are used interchangeably and shall also apply to other heated enclosures used for processing of materials. Within the scope of this standard, a Class A, Class B, or Class C oven is any heated enclosure operating at approximately atmospheric pressure and used for commercial and industrial processing of materials. A Class A oven shall be permitted to utilize a low-oxygen atmosphere. This standard shall apply to bakery ovens and Class A ovens, in all respects, and where reference is made to ANSI Z50.1, Bakery Equipment — Safety Requirements, those requirements shall apply to bakery oven construction and safety. This standard shall apply to atmosphere generators and atmosphere supply systems serving Class C furnaces and to furnaces with integral quench tanks or molten salt baths. This standard shall apply to Class D ovens and furnaces operating above ambient temperatures to over 5000°F (2760°C) and at pressures normally below atmospheric to 10 8 torr (1.33 × 10 6 Pa).
ANSI/ASHRAE 103-2017
Method of Testing for Annual Fuel Utilization Efficiency of Residential Central Furnaces and Boilers
The purpose of this standard is to provide procedures for determining the annual fuel utilization efficiency of residential central furnaces and boilers. This standard includes (a) a test method for cyclic and part-load performance; (b) methods for interpolating and extrapolating test data, and (c) calculation.
CSA/ANSI Z21.47-21/CSA 2.3-2021
Gas-fired central furnaces
Preface This is the eighth edition of CSA/ANSI Z21.47 • CSA 2.3, Gas-fired central furnaces . It supersedes the previous editions published in 2016, 2012, 2006, 2003, 2001, 1998, and 1993. The major changes to this edition include the following: • In Clause 3, the Definitions clause, links have been added to the definition of "flue losses". A publication reference has been added to the definition of "heat deflection temperature". The definition of "heating capacity" has been relocated from footnote to Clause 3. The definition for "air-intake pipe" has been added as recommended by the Z21/83 TC for non-metallic venting. The definition for "vent terminal (vent cap)" has been deleted. The definition for "vent terminal" has been revised. • The clause on direct vent has been relocated from Clause 6.8.5 to Clause 4.2.6 as proposed by the Z21/83 TC for non-metallic venting. • Clause 4.10.1 has incorporated an interim provision for significant updates to ANSI Z21.20. • In Clause 4.11.2, existing requirement has been clarified. The current requirements continue only to allow an accessible switch that is integral to the gas control and the only change to the clause is the change from "manually" to "directly" for interrupting electric power to automatic valves. For clarification of the intent of the switch, the term "manually activated" has been proposed to describe the type of switch. • To accommodate higher discharge air temperatures, Clause 8.7 has been modified for recreational vehicles. If all testing can be passed at the higher temperatures, the restrictions found in the current Clause 4.12.4 for residential style furnaces can safely be eliminated. • Clause 4.14.14.2, method of test for venting components, has been modified to comply with the Z21/83 TC proposal for non-metallic venting. • Clause 4.23 on installation manuals has been modified to clarify the conditions under which the furnace must operate when used during the last stages of construction (finishing heat) and prior to occupancy. • Clarification has been added to Clause 4.23.4 to exclude the use of an external pressure test port. • In Clause 4.23.6, guidance has been added on testing non-metallic vent pipe without or with thermal insulation, minimum distance from adjacent public walkways, adjacent buildings, openable windows, building openings, protecting building materials from degradation by flue gas, instructions for maximum and minimum vent equivalent length, and instruction to cover building wall penetrations. • In Clause 5.4 on test gases, an option has been added to conduct burner operating characteristic tests with Test Gas G or H. • In Clause 5.27.7.2, an option has been added to allow the elbow to be installed inside the enclosure and to allow the use of materials not listed in Table 15 that are tested to ASTM D648. Materials have been removed from Table 15 that are not commonly used. • In Clause 5.29.4.2, on the method of test for electrical leakage current evaluation, UL 1995 has been replaced with UL 60335-2-40. • In Clause 5.35.2, on the method of test on venting systems for Category II, III, or IV furnaces, the calculation for allowable leakage rate has been corrected. • In Clause 6.11.1, on rating plates, an option has been added to list "direct or non-direct vent forced air furnace" as a configuration. • Clause 7.4.11, on vent-air intake terminal pendulum load test, has been added based on the Z21/83 TC proposal for non-metallic venting with modifications for furnaces. • In Clause 8.11.4, on installation marking, the specification for insulation ductwork needed to comply with Clause 9.6 has been added. • In Clause 13, on items unique to Canada, reference to 3 phase furnaces has been corrected. 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. This Standard has been approved by the American National Standards Institute (ANSI) as an American National Standard. Scope 1.1 This Standard applies to automatically operating gas-fired central furnaces (see Clause 3), hereinafter referred to as furnaces, for installation in residential, commercial, and industrial structures including furnaces for direct vent, recreational vehicle, outdoor, and manufactured (mobile) homes. These furnaces can include a cooling unit. All units are to be constructed entirely of new, unused parts and materials. 1.2 In Canada, this Standard applies to gas-fired central furnaces having inputs up to and including 400 000 Btu/h (117 228 W). 1.3 This Standard applies to Category I, Category II, Category III, and Category IV central furnaces. See Clause 3. 1.4 This Standard applies to furnaces of the types defined in Clause 3, which are designed to supply heated air through ducts to spaces remote from or adjacent to the furnace location. Location and use of such furnaces with respect to the spaces being heated necessitates automatic operation of the appliance. 1.5 This Standard covers the thermal efficiency (see Clause 5.40) and related markings of only those furnaces whose efficiencies are not regulated in the U.S.A. by the Energy Policy Act and Conservation Act of 1975 and the National Energy Conservation Policy of 1978* or not covered in Canada by Clause 13 when connected to a single phase electrical supply. Note: * At the time of printing, Federal energy acts in the U.S.A. regulate the efficiency (heating capacity) of furnaces having input ratings less than 225 000 Btu/h (65 941 W). 1.6 A furnace of a type not specifically defined in this Standard may be subjected to such examination and tests as deemed necessary by the testing agency to determine compliance with the intent of this Standard. 1.7 This Standard also applies to a furnace that is factory equipped with both a draft hood and an automatic vent damper device (see Clause 3), hereinafter referred to as vent damper device. 1.8 If a value for measurement as given in this Standard is followed by an equivalent value in other units, the first stated value is regarded as the specification, except as noted in Clauses 4.22.1 and 4.26.2. 1.9 All references to "psi" throughout this Standard are considered gauge pressures, unless otherwise specified. 1.10 Special construction provisions applicable to a furnace designed for use with an optional listed conversion kit are outlined under Annex H. 1.11 Clause 2 contains a list of standards specifically referenced in this Standard. Clause 2 includes both U.S. and Canadian reference standards where applicable. It is the responsibility of the user of this Standard to determine which referenced standard applies based on the requirements of the authority having jurisdiction at the location of the installation. However, a furnace for use in a particular country only should comply with the applicable referenced standard for that country. 1.12 Clause 4.17 is unique to United States. The Canadian electrical equipment and wiring provisions are contained in CSA C22.2 No. 3 or CAN/CSA-C22.2 No. 60335-2-102. 1.13 Special construction provisions applicable to furnaces designed to operate at altitudes over 2000 ft (610 m) are outlined in Annex K. 1.14 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.
AWS C3.6M/C3.6:2016
Specification for Furnace Brazing (AMD September 2022
This specification provides the minimum fabrication, equipment, material, process procedure requirements, as well as inspection requirements for the furnace brazing of steels, copper, copper alloys, and heat- and corrosion-resistant alloys and other materials that can be adequately furnace brazed (the furnace brazing of aluminum alloys is addressed in AWS C3.7M/C3.7, Specification for Aluminum Brazing). This specification provides criteria for classifying furnace brazed joints based on loading and the consequences of failure and quality assurance criteria defining the limits of acceptability in each class. This specification defines acceptable furnace brazing equipment, materials, and procedures, as well as the required inspection for each class of joint.
ANSI/ASHRAE 103-2022
Method of Testing for Annual Fuel Utilization Efficiency of Residential Central Furnaces and Boilers
Provides procedures for determining the annual fuel utilization efficiency of residential central furnaces and boilers. Includes a. a test method for cyclic and part-load performance, methods for interpolating and extrapolating test data, and calculation procedures for establishing seasonal performance. Dual units of measurement.
ASTM D4239-18e1
Standard Test Method for Sulfur in the Analysis Sample of Coal and Coke Using High-Temperature Tube Furnace Combustion
1.1 This test method covers the determination of sulfur in samples of coal or coke by high-temperature tube furnace combustion.
1.1.1 Two analysis methods are described.
1.2 When automated equipment is used, either method can be classified as an instrumental method.
1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.
1.4 All percentages are percent mass fractions unless otherwise noted.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
ANSI Z83.8-2016/CSA 2.6-2016
ANSI Z83.8-2016/CSA 2.6-2016 - Gas unit heaters, gas packaged heaters, gas utility heaters and gas-fired duct furnaces
Preface
This publication represents a basic standard for safe operation, substantial and durable construction, and acceptable performance of a gas unit heater, gas packaged heater, gas utility heater, or gas-fired duct furnace. It is the result of years of experience in the manufacture, testing, installation, maintenance, inspection and research on a gas unit heater, gas packaged heater, gas utility heater, or gas-fired duct furnace designed for utilization of gas. There are risks of injury to persons inherent in appliances that, if completely eliminated, would defeat the utility of the appliance. The provisions in this standard are intended to help reduce such risks while retaining the normal operation of the appliance. Safe and satisfactory operation of gas unit heater, gas packaged heater, gas utility heater, or gas-fired duct furnace depends to a great extent upon its proper installation, use and maintenance. It should be installed, as applicable, in accordance with the National Fuel Gas Code, ANSI Z223.1/NFPA 54; or the Natural Gas and Propane Installation Code, CSA B149.1.Scope
1.1 This standard applies to newly produced gas fired-duct furnaces, packaged heaters and unit heaters with input rates up to and including 10,000,000 Btu/h (2 931 kW) and utility heaters with inputs up to and including 400,000 Btu/hr (117.2 kW) constructed entirely of new, unused parts and materials: a) For use with natural gas with inlet gas pressures up to and including 5.0 psi (34.5 kPa); unit heaters, packaged heaters and duct furnace with burners having inputs rates over 400,000 Btu/hr (117 228 kW) may have higher inlet pressures. b) For use with liquefied petroleum gases; and c) Convertible for use with natural gas and liquefied petroleum gases, when provision is made for the conversion from one gas to the other. 1.2 The term appliance when used herein, applies to gas-fired duct furnaces, packaged heaters, utility heaters and unit heaters. Duct furnaces, unit heaters and package heaters may be factory-built as a single unit or as a package system intended to be disassembled for shipping and reassembled for installation and may be combined with a cooling unit. (See Clause 3). 1.3 Duct furnaces, unit heaters, and packaged heaters may be factory-built as a single unit or as a package system intended to be disassembled for shipping and reassembled for installation, and may be combined with a cooling unit. (See Clause 3). 1.4 The construction of appliances for use with the above-mentioned gases is covered under Clause 4. 1.5 The performance of appliances for use with the above-mentioned gases is covered under Clause 5. 1.6 This standard applies to Category I, Category II, Category III and Category IV Appliances. (See Clause 3). 1.7 This standard covers self-contained, automatically controlled, vented unit heaters, packaged heaters, utility heaters and duct furnaces. These appliances are intended for installation in locations where flammable gases or vapors are not generally present. Unit heaters, packaged heaters and utility heaters shall have an integral means for circulation of air. Unit heaters, unless for outdoor installation are intended for installation in the space being heated. Unit heaters may be either suspended or floor-mounted and of either the low-or high-static pressure type as defined in Clause 3. Utility heaters may be suspended or floor-mounted and of the low static type as defined in Clause 3. Packaged heaters may be either suspended, floor-mounted, or roof mounted and may be located within or external to the heated space as defined in Clause 3. These appliances are suitable for use in aircraft hangars, parking structures and repair garages when marked and installed, as applicable, in accordance with: Standard on Aircraft Hangars, ANSI/NFPA 409; Standard for Parking Structures, ANSI/NFPA 88A; Standard for Repair Garages, ANSI/NFPA 88B; and Installation Code for Natural Gas and Propane Installation Code, CSA B149.1. 1.8 This standard also applies to appliances with draft hoods which are factory equipped with automatic vent damper devices (see Clause 3), hereinafter referred to as vent damper devices. 1.9 A separated combustion system appliance anticipated by this standard is essentially a balanced flue appliance with the air intake and vent outlet in close proximity. Other designs shall be subjected to such additional tests as believed necessary at the discretion of the testing agency. 1.10 Clause 2 contains a list of standards specifically referenced in this standard, and sources from which these referenced standards may be obtained. 1.11 If a value for measurement as given in this standard is followed by an equivalent value in other units, the first stated value is to be regarded as the specification. (See Annex M for Temperature Scales and Conversions). 1.12 Special construction provisions applicable to an appliance designed for use with an optional listed gas conversion kit are outlined under Annex C. 1.13 This standard also applies to newly produced automatic intermittent-pilot ignition systems (see Clause 3), constructed entirely of new, unused parts and materials, to be adapted in the field to a unit heater or duct furnace equipped with an existing continuous pilot burner and which has been examined and tested for compliance with this standard when installed on the appliance. (See Annex D). 1.14 All references to psi (kPa) throughout this Standard are to be considered gauge pressures unless otherwise specified.AWS C3.6M/C3.6:2008
Specification for Furnace Brazing
This specification provides the minimum fabrication, equipment, material, process procedure requirements, as well as inspection requirements for the furnace brazing of steels, copper, copper alloys, and heat- and corrosion-resistant alloys and other materials that can be adequately furnace brazed (the furnace brazing of aluminum alloys is addressed in AWS C3.7M/C3.7, Specification for Aluminum Brazing). This specification provides criteria for classifying furnace brazed joints based on loading and the consequences of failure and quality assurance criteria defining the limits of acceptability in each class. This specification defines acceptable furnace brazing equipment, materials, and procedures, as well as the required inspection for each class of joint.
ASTM A991/A991M-22
Standard Test Method for Conducting Temperature Uniformity Surveys of Furnaces Used to Heat Treat Steel Products
1.1This test method covers the procedures used to conduct a temperature uniformity survey on a furnace used to heat treat steel products. This method is used to determine the capability of the furnace to meet the permissible temperature variation specified in the applicable product specification, or as agreed to by the purchaser and supplier of heat treat services. Survey documentation requirements, and the procedure used to subsequently establish the furnace working zone, are defined in this test method.
1.2This test method covers heat treat furnaces in any of the following categories:
1.2.1Continuous or semi-continuous conveyance furnaces,
1.2.2Batch furnaces, and
1.2.3Salt or liquid baths and fluidized beds.
1.3This test method only applies when specified in the product specification or the purchase order.
1.4Controlling a heat treatment of steel products using thermocouples attached to the extremities of each load is an alternative to performing a furnace survey. The producer shall adhere to Annex A1.
1.5By mutual agreement between the purchaser and the supplier of heat treat services, more stringent and/or additional requirements may be specified. The acceptance of any such additional requirements shall be dependent on negotiations with the supplier and must be included in the order as agreed upon by the purchaser and supplier.
1.6The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.
1.7This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
1.8This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
NFPA 85-2019
NFPA 85 Boiler and Combustion Systems Hazards Code, 2019 edition
The purpose of this code is to contribute to operating safety and to prevent uncontrolled fires, explosions, and implosions in equipment described in Section 1.1. This code establishes minimum requirements for design, installation, operation, training, and maintenance.
ANSI/OPEI B175.2-2012 (R2019)
Outdoor Power Equipment - Internal Combustion Engine-Powered Handheld and Backpack Blowers and Blower-Vacuums - Safety Requirements and Performance Testing Procedures
The requirements of this standard apply to handheld and backpack internal combustion engine-powered blowers and blower-vacuums. This standard does not apply to ride-on, towed, or walk-behind units. This standard does not apply to electrically powered units.
ASTM E145-19
Standard Specification for Gravity-Convection and Forced-Ventilation Ovens
1.1 This specification covers the performance requirements for general-purpose air ovens ordinarily used in testing operations, which have a testing chamber up to 0.6 m3 (25 ft3) in volume. It is applicable to gravity-convection ovens designed to operate over all or part of the temperature range from 20 °C above ambient temperature to 200 °C and to forced-ventilation ovens designed to operate over all or part of the temperature range from 20 °C above ambient temperature to 500 °C.
Note 1: Ovens are designed for maximum operating temperatures of about 200 °C, 300 °C, and 500 °C, the thermal insulation and cost of the oven being dependent on the maximum temperature required.
1.2 This specification does not include safety requirements that are essential for ovens used in the presence of combustible vapors or gases.
1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
ANSI Z21.47-2016/CSA 2.3-2016
ANSI Z21.47-2016/CSA 2.3-2016 - Gas-fired central furnaces
Preface
This is the seventh edition of ANSI Z21.47 / CSA 2.3, Gas-fired central furnaces. It supersedes the previous editions published in 2012, 2006, 2003, 2001, 1998, and 1993.Scope
1.1 This Standard applies to automatically operating gas-fired central furnaces (see Clause 3, Definitions), hereinafter referred to as furnaces, for installation in residential, commercial, and industrial structures including furnaces for direct vent, recreational vehicle, outdoor, and manufactured (mobile) homes. These furnaces may include a cooling unit. All units are to be constructed entirely of new, unused parts and materials. 1.2 In Canada, this Standard applies to gas-fired central furnaces having inputs up to and including 400,000 Btu/hr (117 228 W). 1.3 This Standard applies to Category I, Category II, Category III, and Category IV Central Furnaces. See Clause 3, Definitions. 1.4 This Standard applies to furnaces of the types defined in Clause 3, Definitions, which are designed to supply heated air through ducts to spaces remote from or adjacent to the furnace location. Location and use of such furnaces with respect to the spaces being heated necessitates automatic operation of the appliance. 1.5 This Standard covers the thermal efficiency, Clause 5.40, Thermal efficiency, and related markings of only those furnaces whose efficiencies are not regulated in the U.S.A. by the Energy Policy Act and Conservation Act of 1975 and the National Energy Conservation Policy of 1978* or not covered in Canada by Clause 13, Items unique to Canada, when connected to single phase electrical supply. * At the time of printing, Federal energy acts in the U.S.A. regulate the efficiency (heating capacity) of furnaces having input ratings less than 225,000 Btu/hr (65 941 W). 1.6 A furnace of a type not specifically defined in this Standard may be subjected to such examination and tests as deemed necessary by the testing agency to determine compliance with the intent of this Standard. 1.7 This Standard also applies to a furnace that is factory equipped with both a draft hood and an automatic vent damper device (see Clause 3, Definitions), hereinafter referred to as vent damper device. 1.8 Unless otherwise indicated on its rating plate, a furnace is to be for installation indoors in accordance with its markings and the manufacturer's installation instructions. When specified additional or alternate provisions are met, a furnace may be for manufactured (mobile) home installation or for use outdoors. 1.9 A furnace for manufactured (mobile) home installation is to be designed so when installed in accordance with the manufacturer's installation instructions supplied with the furnace, it provides complete separation of its combustion system from the living space of the manufactured (mobile) home. The complete separation of the furnace combustion system from the living space of the manufactured (mobile) home is accomplished by the furnace being designed and installed so (1) all air supplied for combustion, (2) the combustion system of the furnace, and (3) all products of combustion are completely isolated from the living space. Doors, panels, and any other access openings of the structure serving an enclosure required for such isolation are to communicate only to the outdoors. A furnace that by its inherent design provides such complete separation is referred to as a direct vent central furnace (see Clause 3, Definitions). 1.10 A furnace is for use with one or more of the gases specified in Clause 5.1.1. A furnace for manufactured (mobile) home installation is to be convertible for use with natural gas and propane gas. 1.11 Special construction provisions applicable to Category II, III, or IV furnaces are outlined under Clauses 1.12,4.1.25, 4.13, Condensate disposal, Clauses 4.14.16 through 4.14.18, 4.23.6(d), 4.23.6(h), 4.26.3 (b)(iv), and Clause 4.26.6(f). 1.12 A furnace for indoor installation designed to vent the flue gases horizontally through an outside wall is to be specified as Category III or IV, except Category I furnaces utilizing a listed mechanical venter applied externally to the venting system. 1.13 Special construction provisions applicable to a furnace for manufactured (mobile) home installation are outlined under Clauses 1.8, 1.9, 1.10, 4.1.24, 4.5.5, 4.10.18, 4.23.3(d), 4.23.9, 4.26.3(b)(vi), 4.26.13(a) and Clause 4.26.13(d), and Clause 6. 1.14 Special construction provisions applicable to a furnace convertible for use with natural gas and propane gas are outlined under Clauses 1.10, 4.7.5, 4.11.5(d), 4.26.3(b)(vii), and Clause 4.26.5(a). 1.15 If a value for measurement as given in this Standard is followed by an equivalent value in other units, the first stated value is to be regarded as the specification, except as noted in Clauses 4.22.1 and 4.26.1(b). 1.16 All references to psi throughout this Standard are to be considered gauge pressures, unless otherwise specified. 1.17 Special construction provisions applicable to a furnace designed for use with an optional listed conversion kit are outlined under Annex H, Provisions for listed gas appliances conversion kits (optional). 1.18 Clause 2, Reference publications, contains a list of standards specifically referenced in this Standard and sources from which they may be obtained. Clause 2, Reference publications, includes both U.S. and Canadian reference standards where applicable. It is the responsibility of the user of this Standard to determine which referenced standard applies based on the requirements of the authority having jurisdiction at the location of the installation. However, a furnace for use in a particular country only should comply with the applicable referenced standard for that country. 1.19 Clause 4.17, Electrical equipment and wiring, is unique to the Standard for Gas-Fired Central Furnaces, ANSI Z21.47. The Canadian electrical equipment and wiring provisions are contained in the Standard for Electrical Features of Fuel-Burning Equipment, CAN/CSA-C22.2, No. 3. 1.20 Special construction provisions applicable to furnaces designed to operate at altitudes over 2000 ft (610 m) are outlined in Annex K, Provisions for listed high altitude conversion kits (optional). 1.21 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.AWS C3.6M/C3.6:2008
Specification for Furnace Brazing
This specification provides the minimum fabrication, equipment, material, process procedure requirements, as well as inspection requirements for the furnace brazing of steels, copper, copper alloys, and heat- and corrosion-resistant alloys and other materials that can be adequately furnace brazed (the furnace brazing of aluminum alloys is addressed in AWS C3.7M/C3.7, Specification for Aluminum Brazing). This specification provides criteria for classifying furnace brazed joints based on loading and the consequences of failure and quality assurance criteria defining the limits of acceptability in each class. This specification defines acceptable furnace brazing equipment, materials, and procedures, as well as the required inspection for each class of joint.
ASSE Standard 1082-2018
Performance Requirements for Water Heaters with Integral Temperature Control Devices for Hot Water Distribution Systems
This standard covers water heaters with defined setpoint controls under various steady state flow conditions. ASSE 1082 is for water heaters that control the outlet temperature to specific limits and are installed within a hot water distribution system but not at point-of-use. The water heater shall consist of a heat exchanger, a cold water inlet connection, a hot water outlet connection, and a means for precisely governing the outlet temperature. The water heater controller shall be listed to the appropriate electrical safety standard in accordance with the water heater category. These devices are not intended for end use applications without point-of-use control valves, as specified by ASSE 1016 / ASME A112.1016 / CSA B125.16, ASSE 1069, ASSE 1070 / ASME A112.1070 / CSA B125.70, or other appropriate standards.
CSA/ANSI Z21.10.3-19/CSA 4.3-2019
Gas-fired water heaters, volume III, storage water heaters with input ratings above 75,000 Btu per hour, circulating and instantaneous
Preface This is the ninth edition of CSA/ANSI Z21.10.3 • CSA 4.3, Gas-fired water heaters, volume III, storage water heaters with input ratings above 75,000 Btu per hour, circulating and instantaneous. It supersedes the previous editions published in 2017, 2015, 2014, 2013, 2011, 2004, 2001, and 1998. 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. This Standard has been approved by the American National Standards Institute (ANSI) as an American National Standard. Scope 1.1 This Standard applies to newly produced, large automatic storage water heaters having input ratings above 75,000 Btu/hr (21 980 W), instantaneous water heaters, circulating water heaters including booster water heaters (see Clause 3, Definitions), hereinafter referred to as water heaters or appliances, constructed entirely of new, unused parts and materials: a) for use with natural gas; b) for use with manufactured gas; c) for use with mixed gas; d) for use with liquefied petroleum gases; e) for use with LP gas-air mixtures; f) for recreational vehicle installation for use with liquefied petroleum gases only (see Clause 4.1.27); g) for manufactured home (mobile home) installation convertible for use with natural gas and liquefied petroleum gases when provision is made for the simple conversion from one gas to the other (see Clause 4.1.26); h) for recreational vehicle installation convertible for use with natural gas and liquefied petroleum gases when provision is made for the simple conversion from one gas to the other (see Clause 4.1.27); and i) for use with combination potable water/space heating applications (see Clauses 3, Definitions, and Clause 4.1.30). Automatic storage water heaters having input ratings of 75,000 Btu/hr (21 980 W) or less are covered in Volume I. 1.2 Instantaneous water heaters with input ratings of 200,000 Btu/h (58 614 W) or less, which are designed to deliver water at a controlled temperature of less than 180 °F (82 °C), are subject to Federal minimum efficiency requirements for residential water heaters or covered in Clause 8, Items unique to Canada, are exempt from recovery, thermal efficiencies and standby loss, and related markings required by this Standard. 1.3 Direct vent water heaters anticipated by this Standard are essentially balanced flue appliances with the air intake and vent outlet in close proximity. Other designs are to be subjected to such additional tests as believed necessary at the discretion of the testing agency. 1.4 Water heaters for installation in recreational vehicles are to be of the direct vent type. 1.5 This Standard also applies to water heaters with draft hoods which are factory equipped with automatic vent damper devices (see Clause 3, Definitions), hereinafter referred to as vent damper devices. 1.6 This Standard also applies to water heaters of other than the direct vent type which are factory equipped with electrically operated or mechanically actuated automatic flue damper devices (see Clause 3, Definitions), hereinafter referred to as flue damper devices. 1.7 If a value for measurement as given in this Standard is followed by an equivalent value in other units, the first stated value is to be regarded as the specification, except as noted in Clauses 4.31.2 and 4.32.2. 1.8 All references to "psi" throughout this Standard are to be considered gauge pressures unless otherwise specified. 1.9 Clause 7contains Clauses that are unique to the United States. 1.10 Clause 8contains Clauses that are unique to Canada. 1.11 Special construction Clauses applicable to a water heater designed for use with an optional listed conversion kit are outlined under Annex D, Optional Clauses for listed gas appliance conversion kits. 1.12 Clause 2, Reference publications, contains a list of standards specifically referenced in this Standard, and sources from which these reference standards may be obtained. 1.13 In this Standard, "shall" is used to express a requirement, i.e., a Clause 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.
ASSE Standard 1084-2018
Performance Requirements for Water Heaters with Temperature Limiting Capacity
Water heaters with precise output temperature control under varying flow conditions are used to provide tempered water to the user. As such, they need to limit maximum water temperature at the point of use in order to reduce and control the risks of scalding. ASSE 1084 is intended to provide a level of scald protection consistent with the current ASSE 1070 / ASME A112.1070 / CSA B125.70, Performance Requirements for Water Temperature Limiting Devices. These water heaters are not intended to limit thermal shock and are not substitutes for automatic compensative valves complying with ASSE 1016 / ASME A112.1016 / CSA B125.16, Performance Requirements for Automatic Compensating Valves for Individual Showers and Tub/Shower Combinations.
CSA/ANSI Z21.10.1-19/CSA 4.1-2019
Gas water heaters, volume I, storage water heaters with input ratings of 75,000 Btu per hour or less
Preface This is the eighth edition of CSA/ANSI Z21.10.1 • CSA 4.1, Gas water heaters, volume I, storage water heaters with input ratings of 75,000 Btu per hour or less. It supersedes the previous editions published in 2017, 2014, 2013, 2009, 2004, 2001 and 1998. 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. This Standard has been approved by the American National Standards Institute (ANSI) as an American National Standard. Scope 1.1 This Standard applies to newly produced, automatic storage water heaters having input ratings of 75,000 Btu/hr (21 980 W) or less (see Clause 3, Definitions), hereinafter referred to as water heaters or appliances, constructed entirely of new, unused parts and materials: a) for use with natural gas; b) for use with manufactured gas; c) for use with mixed gas; d) for use with liquefied petroleum gases; e) for use with LP gas-air mixtures; f) for recreational vehicle installation for use with liquefied petroleum gases only (see Clause 4.1.26); g) for manufactured home (mobile home) installation convertible for use with natural gas and liquefied petroleum gases when provision is made for the simple conversion from one gas to the other (see Clause 4.1.25); h) for recreational vehicle installation convertible for use with natural gas and liquefied petroleum gases when provision is made for the simple conversion from one gas to the other (see Clause 4.1.26); and i) for use with combination potable water/space heating applications (see Clause 4.1.29and Clause 3, Definitions). 1.2 This Standard also applies to water heaters incorporating heat pipe heat exchangers (see Clause 4.4, Heat pipe heat exchangers). 1.3 Direct vent water heaters anticipated by this Standard are essentially balanced flue appliances with the air intake and vent outlet in close proximity. Other designs are to be subjected to such additional tests as believed necessary at the discretion of the testing agency. 1.4 Water heaters for installation in recreational vehicles are to be of the direct vent type. 1.5 This Standard also applies to water heaters with draft hoods which are factory-equipped with automatic vent damper devices (see Clause 3, Definitions), hereinafter referred to as vent damper devices. 1.6 This Standard also applies to water heaters of other than the direct vent type which are factory- equipped with electrically operated or mechanically actuated automatic flue damper devices (see Clause 3, Definitions), hereinafter referred to as flue damper devices. 1.7 If a value for measurement as given in this Standard is followed by an equivalent value in other units, the first stated value is to be regarded as the specification, except as noted in Clauses 4.33.2 and 4.34.2. 1.8 All references to "psi" throughout this Standard are to be considered gauge pressures unless otherwise specified. 1.9 Clause 7, Items unique to the United States, contains provisions that are unique to the United States. 1.10 Clause 8, Items unique to Canada, contains provisions that are unique to Canada. 1.11 Special construction provisions applicable to a water heater designed for use with an optional listed conversion kit are outlined under Annex F, Optional provisions for listed appliance conversion kits. 1.12 Clause 2, Reference publications, contains a list of standards specifically referenced in this Standard, and sources from which these reference standards may be obtained. 1.13 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 designed normative (mandatory) or informative (non-mandatory) to define their application.
CSA/ANSI Z21.88-19/CSA 2.33-2019
Vented gas fireplace heaters
Preface This is the ninth edition of CSA/ANSI Z21.88 • CSA 2.33, Vented gas fireplace heaters . It supersedes the previous editions published in 2017, 2016, 2014, 2009, 2005, 2002, 2000, and 1998. Scope 1.1 This Standard applies to newly produced vented gas fireplace heaters (see Clause 3, Definitions), hereinafter referred to as appliance(s), constructed entirely of new, unused parts and materials, and having input ratings up to and including 400,000 Btu/hr (117 228 W): a) for use with natural gas; b) for use with propane; c) direct vent appliances for manufactured home (USA only) or mobile home OEM installation convertible for use with natural gas and propane when provision is made for simple conversion from one gas to the other [see Clause 4.1.4a) and b)]; d) direct vent appliances for manufactured home (USA only) or mobile home aftermarket installation for use with natural gas only or propane gas only [see Clause 4.1.4b)]; e) direct vent appliances for recreational vehicle installation for use with propane gas only [see Clause 4.1.4c)]; f) direct vent appliances for recreational vehicle installation only convertible for use with natural gas and propane gas when provision is made for the simple conversion from one gas to the other [see Clause 4.1.4c)]; and g) for direct vent appliances for manufactured home (USA only) or mobile home OEM installation for use with propane gas only [see Clause 4.1.4a)]. The construction of vented gas fireplace heaters and vented gas fireplace heaters with cooling units for use with the above-mentioned gases is covered under Clause 4, Construction. The performance of vented gas fireplace heaters and vented gas fireplace heaters with cooling units for use with the above-mentioned gases is covered under Clause 5, Performance. 1.2 Clauses 4and 5cover all vented gas fireplace heaters. In addition, Clauses 6and 7address the requirements specific to vented condensing gas fireplace heaters. 1.3 Annex A, Automatic intermittent pilot ignition systems or on-demand pilot ignition systems for field installation, includes provisions for newly produced (optional) automatic intermittent pilot ignition systems and on-demand pilot ignition systems (see Clause 3, Definitions), constructed entirely of new, unused parts and materials, to be adapted in the field to an appliance equipped with an existing continuous pilot burner and which has been examined and tested for compliance with this Standard when installed on the appliance. 1.4 If a value for measurement given in this standard is followed by an equivalent value in other units, the first stated value is to be regarded as the specification. 1.5 All references to "psi" throughout this Standard are to be considered gauge pressures, unless otherwise specified. 1.6 Clause 9, Items unique to the United States, contains provisions that are unique to the United States. 1.7 Clause 10, Items unique to Canada, contains provisions that are unique to Canada. 1.8 This Standard also applies to appliances with draft hoods that are factory-equipped with automatic vent damper devices (see Clause 3, Definitions), hereinafter referred to as vent damper devices. 1.9 Special construction provisions applicable to vented gas fireplace heaters designed for use with an optional design-certified conversion kit are outlined under Annex B, Provisions for listed gas appliance conversion kits (optional). 1.10 Clause 2, Reference publications, contains a list of standards specifically referenced in this Standard and sources from which they may be obtained. 1.11 In this Standard, "shall" is used to express a requirement, i.e., a provision that the user shall 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.
ANSI Z83.25-2017/CSA 3.19-2017
ANSI Z83.25-2017/CSA 3.19-2017 - Direct gas-fired process air heaters
Preface
This is the third edition of ANSI Z83.25 / CSA 3.19, Standard for Direct gas-fired process air heaters. It supersedes the previous edition published in 2015.Scope
1.1 This Standard applies to newly produced, direct gas-fired process air heaters of the recirculating or non- recirculating type (see Clause 3, Definitions), hereinafter referred to as heaters, whose primary purpose is to provide process heating to non-occupied spaces within commercial and industrial buildings and may also include operation as a non-recirculating ventilation air heater (see Clause 3), if the heater is operated during periods when the space is occupied. Heaters covered under this Standard are limited to a maximum discharge temperature of 250 °F (121 °C). Heaters covered by this Standard are not intended for use in any area containing sleeping quarters. The installation conforms with local codes, or in the absence of local codes, in accordance with the National Fuel Gas Code, ANSI Z223.1, or the Natural Gas and Propane Installation Codes, CAN/CSA B149.1. This Standard is intended to cover only complete packaged heaters with integral air moving components, i.e., those which are designed by, cataloged by, and built on a repetitive basis by the manufacturer. 1.2 When the heater operates with people present within the space being served by this heater, it is configured so that the performance window of the heater operation will be in compliance with the applicable provisions associated with the ventilation air heater mode contained in this Standard. 1.3 When the heater is operated in the bake cycle mode, the combustion by-products generated by the heater have not been defined since it is intended to operate in this mode in the non-occupied condition only. 1.4 When the heater is utilized as a paint booth heater, it must be operated as a non-recirculating ventilation air heater during the spraying operation and may be operated as a recirculating heater in the bake or drying mode provided all of the conditions identified in Clauses 4.1.11, 4.1.12, 4.15.3, 4.15.12, 4.15.13, 4.15.14, 4.21.12, 4.21.13, 4.21.14, 4.21.15, 4.21.16, 4.21.17, 4.21.18, 4.21.19, and 4.21.20, if applicable, are met. 1.5 Process air heaters that operate in the bake cycle mode only (does not operate in the occupied mode) are not required to comply with the following construction provisions: Clauses 4.15.5-b) and 4.21.1-m)-iii). 1.6 If a value for measurement as given in this Standard is followed by an equivalent value in other units, the first stated value is to be regarded as the specification. 1.7 Items unique to the U.S.A. are shown in Clause 6. 1.8 Items unique to Canada are shown in Clause 7. 1.9 Clause 2, Reference publications, contains a list of standards specifically referenced in this Standard, and sources from which these referenced standards may be obtained. 1.10 All references to psi through this Standard are to be considered gage pressure unless otherwise specified. 1.11 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; 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.ANSI Z83.8-2016/CSA 2.6-2016
ANSI Z83.8-2016/CSA 2.6-2016 - Gas unit heaters, gas packaged heaters, gas utility heaters and gas-fired duct furnaces
Preface
This publication represents a basic standard for safe operation, substantial and durable construction, and acceptable performance of a gas unit heater, gas packaged heater, gas utility heater, or gas-fired duct furnace. It is the result of years of experience in the manufacture, testing, installation, maintenance, inspection and research on a gas unit heater, gas packaged heater, gas utility heater, or gas-fired duct furnace designed for utilization of gas. There are risks of injury to persons inherent in appliances that, if completely eliminated, would defeat the utility of the appliance. The provisions in this standard are intended to help reduce such risks while retaining the normal operation of the appliance. Safe and satisfactory operation of gas unit heater, gas packaged heater, gas utility heater, or gas-fired duct furnace depends to a great extent upon its proper installation, use and maintenance. It should be installed, as applicable, in accordance with the National Fuel Gas Code, ANSI Z223.1/NFPA 54; or the Natural Gas and Propane Installation Code, CSA B149.1.Scope
1.1 This standard applies to newly produced gas fired-duct furnaces, packaged heaters and unit heaters with input rates up to and including 10,000,000 Btu/h (2 931 kW) and utility heaters with inputs up to and including 400,000 Btu/hr (117.2 kW) constructed entirely of new, unused parts and materials: a) For use with natural gas with inlet gas pressures up to and including 5.0 psi (34.5 kPa); unit heaters, packaged heaters and duct furnace with burners having inputs rates over 400,000 Btu/hr (117 228 kW) may have higher inlet pressures. b) For use with liquefied petroleum gases; and c) Convertible for use with natural gas and liquefied petroleum gases, when provision is made for the conversion from one gas to the other. 1.2 The term appliance when used herein, applies to gas-fired duct furnaces, packaged heaters, utility heaters and unit heaters. Duct furnaces, unit heaters and package heaters may be factory-built as a single unit or as a package system intended to be disassembled for shipping and reassembled for installation and may be combined with a cooling unit. (See Clause 3). 1.3 Duct furnaces, unit heaters, and packaged heaters may be factory-built as a single unit or as a package system intended to be disassembled for shipping and reassembled for installation, and may be combined with a cooling unit. (See Clause 3). 1.4 The construction of appliances for use with the above-mentioned gases is covered under Clause 4. 1.5 The performance of appliances for use with the above-mentioned gases is covered under Clause 5. 1.6 This standard applies to Category I, Category II, Category III and Category IV Appliances. (See Clause 3). 1.7 This standard covers self-contained, automatically controlled, vented unit heaters, packaged heaters, utility heaters and duct furnaces. These appliances are intended for installation in locations where flammable gases or vapors are not generally present. Unit heaters, packaged heaters and utility heaters shall have an integral means for circulation of air. Unit heaters, unless for outdoor installation are intended for installation in the space being heated. Unit heaters may be either suspended or floor-mounted and of either the low-or high-static pressure type as defined in Clause 3. Utility heaters may be suspended or floor-mounted and of the low static type as defined in Clause 3. Packaged heaters may be either suspended, floor-mounted, or roof mounted and may be located within or external to the heated space as defined in Clause 3. These appliances are suitable for use in aircraft hangars, parking structures and repair garages when marked and installed, as applicable, in accordance with: Standard on Aircraft Hangars, ANSI/NFPA 409; Standard for Parking Structures, ANSI/NFPA 88A; Standard for Repair Garages, ANSI/NFPA 88B; and Installation Code for Natural Gas and Propane Installation Code, CSA B149.1. 1.8 This standard also applies to appliances with draft hoods which are factory equipped with automatic vent damper devices (see Clause 3), hereinafter referred to as vent damper devices. 1.9 A separated combustion system appliance anticipated by this standard is essentially a balanced flue appliance with the air intake and vent outlet in close proximity. Other designs shall be subjected to such additional tests as believed necessary at the discretion of the testing agency. 1.10 Clause 2 contains a list of standards specifically referenced in this standard, and sources from which these referenced standards may be obtained. 1.11 If a value for measurement as given in this standard is followed by an equivalent value in other units, the first stated value is to be regarded as the specification. (See Annex M for Temperature Scales and Conversions). 1.12 Special construction provisions applicable to an appliance designed for use with an optional listed gas conversion kit are outlined under Annex C. 1.13 This standard also applies to newly produced automatic intermittent-pilot ignition systems (see Clause 3), constructed entirely of new, unused parts and materials, to be adapted in the field to a unit heater or duct furnace equipped with an existing continuous pilot burner and which has been examined and tested for compliance with this standard when installed on the appliance. (See Annex D). 1.14 All references to psi (kPa) throughout this Standard are to be considered gauge pressures unless otherwise specified.ANSI Z21.10.1-2017/CSA 4.1-2017
Gas water heaters, volume I, storage water heaters with input ratings of 75,000 Btu per hour or less
Preface
This is the seventh edition of ANSI Z21.10.1 / CSA 4.1, Gas water heaters, volume I, storage water heaters with input ratings of 75,000 Btu per hour or less.Scope
1.1 This Standard applies to newly produced, automatic storage water heaters having input ratings of 75,000 Btu/hr (21 980 W) or less (see Clause 3, Definitions), hereinafter referred to as water heaters or appliances, constructed entirely of new, unused parts and materials: a) for use with natural gas; b) for use with manufactured gas; c) for use with mixed gas; d) for use with liquefied petroleum gases; e) for use with LP gas-air mixtures; f) for recreational vehicle installation for use with liquefied petroleum gases only (see Clause 4.1.26); g) for manufactured home (mobile home) installation convertible for use with natural gas and liquefied petroleum gases when provision is made for the simple conversion from one gas to the other (see Clause 4.1.25); h) for recreational vehicle installation convertible for use with natural gas and liquefied petroleum gases when provision is made for the simple conversion from one gas to the other (see Clause 4.1.26); and i) for use with combination potable water/space heating applications (see Clause 4.1.29 and Clause 3, Definitions). 1.2 This Standard also applies to water heaters incorporating heat pipe heat exchangers (see Clause 4.4, Heat pipe heat exchangers). 1.3 Direct vent water heaters anticipated by this Standard are essentially balanced flue appliances with the air intake and vent outlet in close proximity. Other designs are to be subjected to such additional tests as believed necessary at the discretion of the testing agency. 1.4 Water heaters for installation in recreational vehicles are to be of the direct vent type. 1.5 This Standard also applies to water heaters with draft hoods which are factory-equipped with automatic vent damper devices (see Clause 3, Definitions), hereinafter referred to as vent damper devices. 1.6 This Standard also applies to water heaters of other than the direct vent type which are factory- equipped with electrically operated or mechanically actuated automatic flue damper devices (see Clause 3, Definitions), hereinafter referred to as flue damper devices. 1.7 If a value for measurement as given in this Standard is followed by an equivalent value in other units, the first stated value is to be regarded as the specification, except as noted in Clauses 4.33.2 and 4.34.2. 1.8 All references to psi throughout this Standard are to be considered gauge pressures unless otherwise specified. 1.9 Clause 7, Items unique to the United States, contains provisions that are unique to the United States. 1.10 Clause 8, Items unique to Canada, contains provisions that are unique to Canada. 1.11 Special construction provisions applicable to a water heater designed for use with an optional listed conversion kit are outlined under Annex F, Optional provisions for listed appliance conversion kits. 1.12 Clause 2, Reference publications, contains a list of standards specifically referenced in this Standard, and sources from which these reference standards may be obtained. 1.13 In this Standard, shall Is used to express a requirement, i.e.: a provision that the use shall satisfy in order to comply with the Standard; should Is used to express a recommendation or that which is advised by 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 not 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 designed normative (mandatory) or informative (non-mandatory) to define their application.CSA C22.2 No. 46-2013 (R2018)
Electric air-heaters
