This publication represents a basic standard for safe operation, substantial and durable construction, and acceptable performance of performance testing and rating of gas-fired, air - conditioning and heat pumping appliances. It is the result of years of experience in the manufacture, testing, installation, maintenance, inspection and research on performance testing and rating of gas-fired, air-conditioning and heat pumping 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 performance testing and rating of gas-fired, air-conditioning and heat pumping 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 performance testing and rating of gas-fired, air-conditioning and heat pumping 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; or the manufacturers’ installation instructions and local municipal codes.
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 IS INTENDED TO BE USED BY THE MANUFACTURING SECTOR AND BY THOSE APPLYING THE EQUIPMENT AND BY THOSE RESPONSIBLE FOR ITS PROPER INSTALLATION. IT IS THE RESPONSIBILITY OF THESE USERS TO DETERMINE THAT IN EACH CASE THIS STANDARD IS SUITABLE FOR AND APPLICABLE TO THE SPECIFIC USE THEY INTEND.
This standard establishes methods of testing and rating gas-fired, heat pumps for space-conditioning performance. The procedures apply to factory-made, space-conditioning, unitary heat pumps which utilize gas as the primary fuel. This includes engine-driven heat pumps, absorption-cycle heat pumps, desiccant-type heat pumps, and other gas-fired heat pumps. The heat source/sink for the heat pumps may be outdoor air, ground water, or closed-loop water. The heat pumps provide the functions of year-round space conditioning either by direct heating and cooling of air or indirectly by the production of heated and chilled water.
The heat pump may include other functions. Appropriate portions of this standard can be applied to heat pumps which have a gas input that varies so that the output matches the cooling or heating load, to heat pumps which have a single level gas input which varies as a function of ambient conditions, and to heat pumps which have a constant gas input regardless of load or ambient conditions, and to heat pumps with several discrete levels of gas input. In addition to applying to heat pumps which provide year-round space conditioning, portions of this standard can be applied to heat pumps which provide space cooling only or space heating only. Also, procedures are provided for testing and rating water-cooled air conditioners and water-cooled chillers which reject condenser heat with a cooling tower, air- and water-cooled condensing units, and desiccant ventilation-air dehumidifiers.
Section 2 lists the thermal testing that is required for each class of appliance. The type of test and the levels of gas input are prescribed. For air-source/sink appliances, the outdoor temperature conditions are specified, and for water-source/sink appliances, the entering source/sink water temperatures are specified.
Section 3 identifies additional conditions at which the thermal tests specified in Section 2 are to be conducted. This includes the voltage of auxiliary electric input, indoor air quantities, return air temperatures, water flow rates, and return water temperatures.
Section 4 outlines the procedures to be followed when thermal testing. This includes steady-state tests and cyclic tests for the cooling mode, and steady-state tests, cyclic tests, and frost accumulation tests for the heating mode.
Section 5 covers calculation procedures for determining steady-state capacity and input ratings for the appliance operating in the cooling mode. Appropriate adjustments are made to the input and output values determined by the tests to normalize the impacts of auxiliary electric inputs.
Section 6 covers calculation procedures for determining steady-state capacity and input ratings for the appliance operating in the heating mode. Appropriate adjustments are made to the input and output values determined by the tests to normalize the impacts of auxiliary electric inputs.
The next four sections of the standard cover calculation procedures for determining seasonal and annual performance parameters for residential and commercial applications.
Section 7 covers calculation procedures for determining cooling-mode seasonal output and energy consumption ratings for appliances suitable for installation in residential applications. The steady-state cooling ratings from Section 5 are required as inputs for these determinations. A sample calculation is provided in Annex A.
Section 8 covers calculation procedures for determining heating-mode seasonal output and energy consumption ratings for appliances suitable for installation in residential applications. The steady-state heating ratings from Section 6 are required as inputs for these determinations. A sample calculation is provided in Annex B.
Section 9 covers calculation procedures for determining annual energy consumption for appliances suitable for installation in residential applications. The seasonal energy consumption data determined in Sections 7 and 8 are required as inputs for these calculations.
Section 10 covers calculation procedures for determining cooling-mode average hourly output and energy consumption ratings for appliances suitable for installation in commercial applications. The steady-state cooling ratings from Section 5 are required as inputs for these determinations. A sample calculation is provided in Annex C.
Section 11 covers procedures for determining outdoor sound power level ratings for air-source appliances.
Section 12 lists the references used in developing the standard.
Addenda 1 to ANSI Z21.40.4-1996/CGA 2.94-M96, Performance Testing and Rating of Gas-Fired, Air Conditioning and Heat Pump Appliances