The first type of blends incorporate the following refrigerants in two compositions to optimize different performance characteristics. Standard thermometers of appropriate range are provided for the refrigerant system. Understanding a2l refrigerants for air conditioners 2019. The refrigerants have a thermodynamic property charge. Since different fluids have the desired traits in different degree, choice is a. Figure 9 shows the different types of refrigerants. The two refrigerant families most often used in air conditioning systems are hydrochlorofluorocarbons hcfcs and cfcs.
Evaporation is an operation used to remove a liquid from a solution, suspension, or emulsion by boiling off some of the liquid. The following is a list of refrigerants with their type prefix, ashrae designated numbers, iupac chemical name, molecular formula, cas registry number blend name, atmospheric lifetime in years. Refrigerants and their application presented by thomas e. New refrigerants impact standards and codes the function of refrigerant as a fluid used for heat transfer has not changed since the development of the first refrigerating system. R12 was the refrigerant back in the 20th century for automobile applications. The last round of changes took place between the mid1990s through 2010, as cfc and hcfc refrigerants were phased out and. The most common refrigerants for the first 100 years were familiar solvents and other volatile fluids. Water has very different miscibilities with different refrigerants, and this fact has an important impact on the operation of refrigeration systems. From then on, reference to harmful gases from ac system will be clearly understood to imply the refrigerant in the. Manual for refrigeration servicing introduction technicians. New, natural and alternative refrigerants by dr s f pearson of star refrigeration limited introduction it is an honour to be invited to present this paper despite the rather daunting title. Refrigerants r402a, r402b, and r404a properties, uses. The different types of refrigerants can be grouped as given below ashrae 2008.
In the following section, different groups of refrigerants are discussed, some examples are given and their fields of application are described. Volkmar hasse, gtz proklima, germany preface volkmar hasse, gtz proklima i. The development of different refrigerants over time took place based on. Each refrigerant type is denoted by a different series. Transcritical systems where co 2 is used in all circuits mt and lt. Swep is a worldleading supplier of brazed plate heat exchangers for hvac and industrial applications. Commercially, ammonia is made by combining free nitrogen and hydrogen gases under high pressure. Originally the title given was new and alternative refrigerants. Thus many refrigerants have several different names. A refrigerant is a substance, usually a fluid chemical compounds, that is used in a. During the last ten years, co 2 has become a viable refrigerant and can be used in different system setups. Refrigerants for commercial refrigeration applications. Primary refrigerants change states to absorb heat from surrounding areas or substances.
The only way they will work is if you click the link within the ashrae website. A refrigerant is a chemical that is used to provide cooling in a heat transfer system. Properties of refrigerants michigan state university. Refrigerants capture heat and then release it to another space by using the thermodynamic phenomena of phase changes, in which a fluid changes to a gas or vice versa in the refrigeration cycle. Following the discovery that some of these chemical compounds may be harmful to the environment, they are being replaced with more environmentally friendly alternatives see figure 5. Sydney games stated that cfc, hcfc and hfcfree refrigerants. Originally the title given was new and alternative refrigerants but i was. Its functions include drawing in the cool vaporized refrigerant that carries. Policylegislation on fgases and alternatives two environmental frameworks one goal the montreal protocol and the kyoto protocol. Where a specific molecule can have different geometrical arrangements. Characteristics of refrigerants pure r12 cc 1425f425 is colorless.
Special university course for future engineers lecture notes. Refrigerants physical properties engineering toolbox. This section presents data for the thermodynamic and transport properties of refrigerants, arranged for the occasional users. There are many kinds of refrigerant and or refrigerant on the market today, but only a few that are widely used. Refrigerant grade anhydrous ammonia is a clear, colorless liquid or gas, free.
Without being pressureregulated, primary refrigerants. If a refrigeration system is leak free, use of the existing. The following links are to online readonly versions of these standards. Co 2 transcritical systems have also been driving the development of integrated heating and cooling systems, linking the refrigerant choice to the type of system. What are the most common types of refrigerant today. Natural refrigerants sustainable ozone and climatefriendly alternatives to hcfcs introduction dr. The danfoss product range for the refrigeration and air.
Main types of compressors used in industrial refrigeration are screw, piston, centrifugal and rotary vane. Common refrigerants and environmental safety thermal systems. Class 2 refrigerants are used as direct cooling between the agents of class 1 and substances in the refrigerator. The different types of cooling compressors a compressor acts as the heart of a refrigerant based mechanical cooling system. Originally the title given was new and alternative refrigerants but i was also asked to. This type of magnetic refrigeration is said to produce refrigeration at. Designation and safety classification of refrigerants. Below is a list of the different oil types for the different refrigerants in our units. It was banned in 1994 due to it harming the ozone layer. Pdf refrigerant types, issues, trends and future options. Another type, which is produced in large quantities, a scroll compressor, but still these compressors. Always check the compressor manufactures recommendations for oil on any other type of cooling unit.
Properties of refrigerants n low boiling point and high latent heat of vaporization n dense vapor n low toxicity n non flammable n low miscibility with oil n low cost ammonia n has good heat transfer. Designed to make the most efficient use of energy, material, and space, the technology is quickly. Six types of refrigerant emissions, or losses, are identified. The choice of prefix is free but the best choice will normally be the one where the value written will be in the range from 0. Refrigeration and air conditioning multiple choice questions. Both types involve the use of refrigerant blends to achieve alternatives that will act very much like r502 in refrigeration systems. The process is not easy, and although there are alternatives to old refrigerants, the new ones are usually not flawless. Here are some of the desirable properties of refrigerant. During the refrigeration cycle, it changes from one state to the. Refrigerants are widely used in refrigeration cycle where cooling effect below the atmospheric temperatures are needed. Class 1 refrigerants used in the standard compression type cooling system. Prefixes should not be used for combined siunits except when kg is.
Refrigerants used in air conditioners are changing again. Whenever we choose them for particular use properties of refrigerants also plays a vital role in economic and environmental friendly application. Simulate your system with the right refrigerant and export the results to excel. The process is not easy, and although there are alternatives to old refrigerants.
Designation and safety classification of refrigerants, which specifies refrigerant properties and a refrigerant classification system. Halocarbon refrigerants halocarbon refrigerant are all synthetically produced and were developed as the freon family of refrigerants. In most cycles it undergoes phase transitions from a liquid to a gas and back again. Standard 15 is the basis for the criteria on refrigeration safety in the. The refrigerant in a refrigeration system, regardless of type, is present in two different states. Refrigerants and the refrigeration system determine the pressures. Synthetic and organic refrigerants are classified under two main categories, primary and secondary.
Compare performance of multiple refrigerants, learn the line sizing, and much more all for free. Thus, we have separate series for halogenated refrigerants and other types. Refrigerant types, issues, trends and future options. A refrigerant is a substance or mixture, usually a fluid, used in a heat pump and refrigeration cycle. Knowing the temperature difference across the coils, the amperage, and the airflow all give the technician vital information. Present a comparison between different refrigerants section 26. Fellow ashrae mcquay international staunton, virginia usa 1 what is a refrigerant. Type of refrigerant and its availability if a system uses a chlorofluorocarbon cfc then it is likely to. The different types o f refrigerants can be groupe d as given below ashrae 2008.
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