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While pipe sizes in Australia are inch-based, they are classified by outside rather than inside diameter (e.g., a nominal 3 ⁄ 4 inch copper pipe in Australia has measured diameters of 0.750 inches outside and 0.638 inches inside, whereas a nominal 3 ⁄ 4 inch copper pipe in the U.S. and Canada has measured diameters of 0.875 inch outside and ...
According to ASHRAE standard 34, the R-number of a chemical refrigerant is assigned systematically according to its molecular structure and has between two and four digits. If there are carbon -carbon multiple bonds , there are four digits in all: the number of these bonds is the first digit and the number of carbon atoms minus one (C-1) is next.
The pipe contents must be identified adjacent to the banding. [2] This can be done by giving either: The full name; Abbreviation; Chemical symbol; Refrigerant number; Coloured bands (user specified) The direction of flow should also be identified near the banding. [2] Examples using this system are as shown. Examples of pipe marking using BS 7010
R-410A is a refrigerant fluid used in air conditioning and heat pump applications. It is a zeotropic but near-azeotropic mixture of difluoromethane (CH 2 F 2, called R-32) and pentafluoroethane (CHF 2 CF 3, called R-125). R-410A is sold under the trademarked names AZ-20, EcoFluor R410, Forane 410A, Genetron R410A, Puron, and Suva 410A.
R-407C is a mixture of hydrofluorocarbons used as a refrigerant. It is a zeotropic blend of difluoromethane (R-32), pentafluoroethane (R-125), and 1,1,1,2-tetrafluoroethane (R-134a). Difluoromethane serves to provide the heat capacity, pentafluoroethane decreases flammability, tetrafluoroethane reduces pressure. [ 1 ]
To use smaller tubes instead of conventional-sized tubes in air conditioners, heat exchangers must be redesigned including the fin and tube circuits. [12] Design optimization requires the use of computational fluid dynamics to analyze airflow around the tubes and fins, as well as computer simulations of refrigerant flow and temperatures inside the tubes.
HCFC-123 is used in large tonnage centrifugal chiller applications, and is the most efficient refrigerant currently in use in the marketplace for HVAC applications. HCFC-123 is also used as a testing agent for bypass leakage of carbon adsorbers in gas filtration systems, and as the primary chemical in Halotron I fire-extinguishing agent. [2]
The ASHRAE Handbook is the four-volume flagship publication of the nonprofit technical organization ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers [a]).