Detailed comparison is made on first generation, second generation and third generation refrigerants, including the option of. In fact, from the thermodynamic or heatcarrying standpoint, differences among refrigerants with similar. Refrigerants are the working fluids used in the counter clockwise thermodynamic working cycles. Whenever we choose them for particular use properties of refrigerants also plays a vital role in economic and environmental friendly application. A comparison between refrigerants used in air conditioning. However, hfcs still dominate the market outright and natural refrigerants, despite their superior properties, still. May 28, 2018 cfc and hcfc refrigerants freon, arcton, etc. Usually, a fluid, used in a heat pump and refrigeration cycle that can extract heat from another body or substance. Refrigerants and vars refrigerants and their properties the working agent in a refrigerating system that absorbs carries or releases heat from the place to be cooled or refrigerated can be termed as a refrigerant. The following is a list of refrigerants with their typeprefix, ashrae designated numbers, iupac chemical name, molecular formula, cas registry number blend name, atmospheric lifetime in years, semiempirical ozone depletion potential, net global warming potential over a 100year time horizon, occupational exposure limitpermissible exposure. Detailed comparison is made on first generation, second generation and third generation refrigerants, including the option of using hcs and co 2. To enable the use of smaller compressors and other equipment the refrigerant should have smaller vapor density.
Product information sorted by product type and name type product r number odp1 gwp2 cfc 12 1 high 10900 high 502 0,33 high 4657 high hcfc 22 0,055 medium 1810 medium 123 0,060 medium 77 low 401a 0,033 medium 1182 medium. Refrigerants are widely used in refrigeration cycle where cooling effect below the atmospheric temperatures are needed. Modeling and evaluation tools 2 characterize the heat transfer and thermodynamic properties and efficiency performance of new refrigerants and blends. The following is a list of refrigerants with their typeprefix, ashrae designated numbers, iupac chemical name, molecular formula, cas registry number blend name, atmospheric lifetime in years, semiempirical ozone depletion potential, net global warming potential over a 100year time horizon, occupational exposure limitpermissible exposure limit in parts per million volume per volume over a timeweighted average twa concentration for a normal eighthour work day and a 40hour work. R22 light green r4a light sky blue r404a orange the name label of the gases are given on the cylinder. In the hvac industry, refrigerants are used in various equipment such as air conditioners, refrigerators, freezers, etc. The choice of perfect refrigerant is made in view of its ideal thermodynamic properties, nondestructive nature, and security nonharmful and noncombustible. Refrigerants refrigeration systems and applications. It is the fluid that flows continuously through the refrigeration cycle or vapor compression cycle absorbing heat from the low temperature reservoir and throwing it to the atmosphere or. Poe oil, or poly olester oil, is a synthetic oil that was designed to meet the needs of the changing refrigeration industry. New refrigerant development 10 develop techniques for detecting and dramatically reducing refrigerant leakage in currently installed.
Properties of oil and refrigerant mixtures lubrication of ball bearings in refrigeration compressors. Here are some of the desirable properties of refrigerant explained in detail. Refrigerants and their application presented by thomas e. As for example, we cannot allow a toxic refrigerant to be used for air conditioning in residential buildings. Ashrae position document on refrigerants and their. Oct 25, 2018 first and secondgeneration refrigerants were composed of natural refrigerants and hydrocarbons hcs, both of which do not impact the environment, have low gwp, and zero ozonedepletion potential. In the last two centuries, human ingenuity made it possible to control fully. High latent heat of vaporization to get more refrigeration effect.
Fellow ashrae mcquay international staunton, virginia usa 1 what is a refrigerant. The infoimation developed in this study on the environmental impacts and the properties of various refrigerants can be used by designers in seeking to provide better and environmentally friendlier refrigeration and air conditioning systems. A general definition of refrigerant isfluid used in refrigeration system for transferring heat 3. The refrigerant in any refrigerator or air conditioner flows continuously through the vapor compression cycle, absorbing the heat in the evaporator and releasing it in the condenser. The refrigerants have a thermodynamic property charge. Section 2 discusses the environmental impacts of refrigerants through their life.
It was soon evident, though, that the lack of chlorine and that the new ester oils did not have the same good lubrication properties as mineral oil and cfc refrigerants. Characteristics solstice 452a r452a is a nonozonedepleting, non. 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. Hence, new synthetic ester lubricants were developed for this application. Refrigerants are substances that can be used in the refrigeration cycle of air conditioning and refrigeration equipment because of their thermodynamic properties. Refrigerant circulates within the refrigeration machine. The following is a list of refrigerants with their typeprefix, ashrae designated numbers, iupac chemical name, molecular formula, cas registry number blend name, atmospheric lifetime in years, semiempirical ozone depletion potential, net global warming potential over a 100year time horizon, occupational exposure limitpermissible exposure limit in parts per million volume per volume over a. The choice of the refrigerant is not only the technical problem, it is subject to lot of interests, public and in dustrial groups advocate their positions and neutral po. Refrigerants with suitable properties are chosen for selective cooling and heating applications. This article describes thermodynamic properties of the refrigerants the ideal refrigerant. Jun 02, 2019 a refrigerant is a substance or mixture. It is intended for use by persons having technical skill, at their own risk. Possible replacements for these refrigerants in commercial applications include ashrae class 2l refrigerants, which have lower global warming potentials but are mildly flammable. The good properties of a refrigerant are as follows.
Comparison of environmental impacts and physical properties of refrigerants ko matsunaga executive summary even before the invention of refrigeration, people wanted to improve their life by using ice to provide cold drinks and preserve food. Thermodynamic properties of duponttm freonr 22 refrigerant author. The specific heat of liquid should be as small as possible and of vapour should be as high as possible to give less superheating of vapour. The flood of the airconditioner, that is, the refrigerants, their properties, merits and demerits are summarized to map the various types and their classifications. For decades, freon refrigerants have been the trusted choice for their performance, reliability, and safety in air conditioning and refrigeration applications. The most common types of refrigerants in use nowadays are presented below. Sustainability safeguards longterm investments and ensures compliance with corporate social responsibility csr. Risk assessment of refrigeration systems using a2l flammable. The refrigerant in a mechanical compression system absorbs andchange state 2. This refrigerant was introduced commercially in the early 1960s for low temperature applications and is particularly suitable for hermetic compressors.
The r22 refrigerant which is used as an alternative to cfcincluded refrigerants, has got a low odp value and thus, its use is permitted until the year 2030. After studying this unit, you should be able to learn the different classifications of refrigerants, naming convention for refrigerants, properties of individual refrigerants, and. For example, the classification of halogen refrigerants derived from saturated hydrocarbons and consisting of only one substance is illustrated in fig. Refrigerant is the life blood of the vapor compression cycle. Desirable properties and commonly used refrigerants. As a result, a refrigerant that has similar thermodynamic properties could be an alternative to r22. Greenhouse effect global warming clean air act caa alternative refrigerants. All refrigerants are dangerous if misused or applied incorrectly. Refrigerant development and legal situation stratospheric ozone depletion as well as atmospheric greenhouse effect due to refrigerant emissions have led to drastic changes in. This information is based on values calculated using the nist refprop database mclinden, m.
Chlorofluorocarbons cfcs, hydrochlorofluorocarbons hcfcs and hydrofluorocarbons hfcs are synthetic substances used as refrigerants. Examples of secondary refrigerants include water, air, hydrocarbons, ammonia and carbon dioxide, which are more environmentally benign than traditional refrigerants such as hcfcs. These physical properties of refrigerants help us select the proper refrigerant for the application as per our requirement. Secondary refrigerants allow the amounts of environmentally harmful primary refrigerants to be minimized and contained in a restricted area. Cfc 12 and hcfc 22 have an aggregated average above 51%. Refrigerant options now and in the future white paper. Refrigerants absorbs heatby evaporating from a liquid to a vapor 4. The most common hfc refrigerants available since the ban on hcfcs are presented in table 5. Further information can be found in the latest version of standard 34, available. Refrigerants are substances, often in liquid form that are used in a refrigeration cycle to cool a certain space. Primary refrigerants change states to absorb heat from surrounding areas or substances. Freon refrigerant for more information on freon refrigerants, visit the information set forth herein is furnished free of charge and based on technical data that chemours believes to be reliable. Without being pressureregulated, primary refrigerants absorb all available heat.
Thermodynamic properties of duponttm freonr 22 refrigerant. For decades, freon refrigerants have been chosen for their performance and safety for all residential and commercial ac, heat pumps, and refrigeration. Refrigeration as we know it has its origins in the. The standard industry number designation for each refrigerant is the signed by. R4a has relatively low pressure and therefore about 50% larger compressor displacement is required when compared to r22.
It is the fluid that flows continuously through the refrigeration cycle or vapor compression cycle absorbing heat from the low temperature reservoir and throwing it to the atmosphere or any other high temperature reservoir. The process is not easy, and although there are alternatives to old refrigerants, the new ones are usually not flawless. Types of refrigerants and their environmental impact. Pdf refrigerant types, issues, trends and future options. The hydrofluorocarbons are refrigerants that contain no chlorine and are not harmful to the ozone layer odp 0, see section 5. These refrigerants are primarily used for air conditioning and heat pumps and have replaced r22 in many applications. Albeit numerous liquids can be utilized as a refrigerant, however in the twentieth century, cfcs turned into the most prevalent refrigerants. Historically, oliver evans 1805 pioneered the idea of refrigeration by using ether.
Refrigerant is the fluid used for heat transfer in a refrigerating system that absorbs heat. However, their impact on global warming is very large compared with traditional refrigerants. Due to the chlorine molecules ability to destroy the earth ozone layer by converting it to oxygen the international communities have agreed through a number of conventions to bring about its phaseout of such refrigerants. This heat transfer generally takes place through a phase change of the refrigerant. Synthetic and organic refrigerants are classified under two main categories, primary and secondary. There are some refrigerants which are highly inflammable and so their. While having less impact on the environment, flammable refrigerants. This section presents data for the thermodynamic and transport properties of refrigerants, arranged for the occasional users. Desirable properties of refrigerants used in refrigeration applications like. A summary of most common refrigerants and their oil compatibility is detailed below.
The journey toward compliance has caused the hvac equipment and appliance industries to revisit the potential use of substances that have good environmental and thermodynamic properties as refrigerants, but which are also, unfortunately, flammable. Duponttm refrigerants, technical information keywords. A number of materials have physical and thermodynamic properties suitable for their use as refrigerants. The globalwarming potential gwp of refrigerants now became a factor.
Refrigerants are divided into groups according to their chemical composition. Sep 17, 2014 color codes of refrigerants easy recognize gas cylinder different refrigerant has different color coding few examples are given below. A refrigerant with a ozonedepletion potential odp damages the ozone layer, which is an entirely separate issue from climate change. Properties of refrigerants n low boiling point and high latent heat of vaporization n dense vapor n. Desirable properties of refrigerants chemical engineering site. Ashrae position document on refrigerants and their responsible use 2 executive summary refrigerants are the working fluids in refrigeration, airconditioning, and heatpumping systems. They absorb heat from one area, such as an airconditioned space, and reject it into another, such as outdoors, usually through evaporation and condensation. Request pdf properties of refrigerant, oil and their mixture in most vapourcompression refrigeration systems, a certain amount of lubricant oil is used to lubricate moving parts. Common refrigerants and their ozone depletion potential odp and global warming potential gwp are indicated below.
Ozone depletion potential odp of a chemical compound is the relative amount of degradation it can cause to the ozone layerglobal warming potential gwp is a measure of how much a given mass of a gas contributes to global warming. Refrigerants thermodynamic, physical, chemical, safety related and environmental properties have been presented and discussed in the first part of the paper. Natural and synthetic refrigerants, global warming. Due to their low odp, the phaseout dates for hcfcs were set out later from 2004 to 2030 2040 in developing countries. Usually, a fluid, used in a heat pump and refrigeration cycle that can extract heat from another body or. Influence of those properties, which is of the utmost significance on the vapor compression process effi. Many different refrigerants have been used in the past and are in use today with good ability to transfer heat from one place to another. Properties of refrigerant, oil and their mixture request pdf. Chemical refrigerants are assigned an r number which is determined systematically according. High critical temperature to have large isothermal energy transfer. The primary refrigerants used in commercial reachin and walkin coolers are r404a and r4a, greenhouse gases with global warming potentials gwps in excess of 1,400.
Low boiling temperature at atmospheric of the refrigerant is desirable. It is responsible for capturing heat and then releasing it to another space by using the thermodynamic phenomena of phase changes wherein fluid changes into gas. An understanding of the pressuretemperature relationship of refrigerants as theypass through the refrigeration compression cycle also will help you as you study this chapter on refrigerant tables. Depending on temperature levels of the heat source and the heat sink, the application area of the working cycle can be refrigeration, air conditioning, or heatpumping. Hfc refrigerants are not miscible with the mineral oils used in cfc refrigeration systems. The following is a list of refrigerants with their type prefix, ashrae designated numbers, iupac chemical name, molecular. R12 overview r12 is r4as older predecessor, and it was used in most automotive air conditioning systems, as well as in household refrigerators. Purchasing freon refrigerants by the chemours company provides a reliable supply of highquality refrigerants to use in new equipment and retrofit opportunities, and to service. Apr 12, 2020 refrigerants are widely used in refrigeration cycle where cooling effect below the atmospheric temperatures are needed. There are some refrigerants which are highly inflammable and so their direct use is forbidden for safety reasons. Compressor has to be operated at high vacuum if the boiling point of the refrigerant is high at atmospheric pressure.
While having less impact on the environment, flammable refrigerants are significantly more easily. Properties of commonly used refrigerants a refrigerant is a substance or mixture. Their report showed that chlorine was a key factor in the destruction of the ozone layer in the upper atmosphere. Effects of refrigerant properties on refrigerant performance citeseerx. Refrigerants that commonly used mineral oils were your cfc and hcfc refrigerants such as r12, r22, and r502. It has long been used in a variety of airconditioning and refrigeration applications in a variety of markets. A familiarity with these diagrams will make this chapter easier. The tables contained on this page list approved refrigerant numbers from ansiashrae 342019, designation and safety classification of refrigerants, the latest edition of standard 34, which describes a shorthand way of naming refrigerants and assigns safety classifications based on toxicity and flammability data. Genetron properties suite provides results in tabulated form exportable to excel and in diagrams you are used to pressureenthalpy, temperatureentropy. Refrigerants are classified by ashrae, and their familiar r numbers are assigned according to certain rules. Mineral oils can also be used with other refrigerants such as ammonia or some hydrocarbons as well.
Without being pressureregulated, primary refrigerants absorb all available heat from perishable goods until theyre frozen solid. In the 1990s, concerns grew that the refrigerants being phased in because of their favorable odp were contributing to global warming. This unit is intended to serve as an introductory guide to the study of refrigerants. Human society was using refrigeration technology, even before the invention of electricity in the 1880s. Refrigerants release heatby condensing from a vapor to a liquid 5.