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This publication represents a basic standard for safe operation, substantial and durable construction, and acceptable performance of gas-fired, heat activated air conditioning and heat pump appliances. It is the result of years of experience in the manufacture, testing, installation, maintenance, inspection and research on gas-fired, heat activated air conditioning and heat pump appliances 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.
Nothing in this standard is to be considered in any way as indicating a measure of quality beyond compliance with the provisions it contains. It is designed to allow compliance of gas fired, heat activated air conditioning and heat pump appliances, the safety construction and performance of which may exceed the various provisions specified herein. In its preparation, recognition has been given to possibilities of improvement through ingenuity of design. As progress takes place, revisions may become necessary. When they are believed desirable, recommendations or suggestions should be forwarded to the Chairman of Accredited Standards Committee Z21, 8501 East Pleasant Valley Road, Cleveland, Ohio 44131, or the Chairman of the Canadian Gas Association Standards Steering Committee on Gas Burning Appliances and Related Accessories, 55 Scarsdale Road, Don Mills, Ontario, Canada, M3B 2R3.
Safe and satisfactory operation of gas-fired heat activated air conditioning appliances 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; the Natural Gas Installation Code, CAN/CGA-B149.1; the Propane Installation Code, CAN/CGA-B149.2.
Users of this American National Standard/Canadian Gas Association Standard are advised that the devices, products and activities within its scope may be subject to regulation at the Federal, Territorial, Provincial, state or local level. Users are strongly urged to investigate this possibility through appropriate channels. In the event of a conflict with this standard, the Federal, Territorial, Provincial, state or local regulation should be followed.
NOTICE TO READER: The Canadian Gas Association (CGA) has been accredited by the Standards Council of Canada to prepare standards in the area of equipment for use with natural gas and propane. Standards are prepared by committees that include representatives from all interests and are so constituted that no one interest may dominate. The interests represented include governmental inspection authorities, certification agencies, manufacturers, utilities, and consumers. Government inspection authorities having jurisdiction review and approve these standards; sitting as the Interprovincial Gas Advisory Council (IGAC).
This standard applies to newly produced, gas-fired, heat activated, air conditioning and heat pumping appliances, hereinafter referred to as appliances, constructed entirely of new, unused parts and materials, which are designed to supply conditioned air; heated and/or cooled liquid; or refrigerants, gases, solids, or liquids to spaces remote from or adjacent to the appliance. Heat activated appliances are those appliances whose heating, cooling, or dehumidifying effect is directly energized by the thermal output of fuel gas combustion.
Location and use of such appliances with respect to the spaces being conditioned necessitates automatic operation to provide even comfort and customer convenience. Accordingly, only automatically operated appliances will be accepted for examination under this standard.
Appliances covered by this standard include, but are not limited to, one or a combination of the following and may also incorporate additional function(s):
- Gas-Fired Absorption Air Conditioner;
- Gas-Fired Adsorption Air Conditioner;
- Gas-Fired Absorption Heat Pump;
- Gas-Fired Adsorption Heat Pump.
When the appliance incorporates a function not specifically covered by this standard (e.g., if an electric vapor-compression type refrigeration unit is combined with an appliance in a common casing) the function shall comply with the applicable provisions of a nationally recognized appropriate standard(s).
An appliance shall be for use with one or more of the gases specified in 2.1.1. Also see 2.2.
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.
All references to psi throughout this standard are to be considered gage pressures unless otherwise specified.
Exhibit D contains Items Unique to One Country (U.S.).
Exhibit E contains Items Unique to One Country (Canada).
Exhibit F contains a list of standards specifically referenced in this standard and sources from which these referenced standards may be obtained.
All tables and figures are located after the Exhibits and before Part III.
Addenda 1 to ANSI Z21.40.1-1996/CGA 2.91-M96, Gas-Fired, Heat Activated Air Conditioning and Heat Pump Appliances