Other refrigerants not listed above are also applied in products outside of daikins portfolio, some examples include hydrocarbons isobutane, propane for refrigerators and window air conditioners or hfo refrigerants for mobile air conditioners. Ozone depletion potential odp of a chemical compound is the relative amount of degradation it can cause to the ozone layer. Risk assessment of refrigeration systems using a2l. The hcfcs have a 2 to 10% ozone depleting potential as compared to cfcs and also, they have an atmospheric lifetime between 2 to 25 years as compared to 100 or more years for cfcs brandt, 1992. Cfc 11, or r11 has the maximum potential amongst chlorocarbons because of the. Find powerpoint presentations and slides using the power of, find free presentations research about refrigerants ppt. Today, the environmental spotlight is shifting to the gwp of refrigerants. Greenhouse gases like hfcs trap the suns heat, bringing unwanted changes to the earths environment. Characteristics of some new generation refrigerants with low. The low ozone depletion potential of r22 compared to cfc11 chlorofluorocarbon 11 and cfc12. Save energy and the environment ozone depletion and global warming rank high among the unintended changes brought about by human activities since the industrial revolution. Find out information about ozone depletion potential.
Odp is defined as the integrated change in total ozone per unit mass. Refrigerant types, issues, trends and future options. The treatment by leed of the environmental impact of hvac. Low gwp refrigerant ozonedepletion potential zeroodp. Odp is expressed as a relative potential of ozone depletion compared to influence of r11 which has odp1. Growing demand for refrigeration and airconditioning with diversified applications has led to a continued search. However, halogenated refrigerants possess comparatively poor environmental properties with respect to ozone depletion potential odp and global warming potential gwp. Cfcs class ii substance ozone depleting chemical with an ozone depletion potential. Refrigerants containing chlorine or bromine contribute to the breakdown of the ozone layer see figure 5. R4a is widely used in automotive air conditioning and residential, commercial and industrial refrigeration systems, but also as a blowing agent for rigid foam insulation materials production. Hcfc22 hfc125 propane freon hp80 r402a, wt% 38 60 2 freon hp81 r402b, wt% 60 38 2 in addition, chemours has formulated a mixture based on allhfc refrigerants, which results in no ozone depletion factor. Global warming potential gwp is the ratio of the warming caused by a substance compared to the warming caused by a similar mass of carbon dioxide. Investigation into the fractionation of refrigerant blends. Unlike alkyl halide refrigerants that contain bromine or chlorine, r410a which contains only fluorine does not contribute to ozone depletion and is therefore becoming more widely used, as ozonedepleting refrigerants like r22 are phased out.
Companies like honeywell are to looking into redesigning appliances like air conditioners and refrigerant applications that have a lower gwp. Alternatives to ozone depleting refrigerants in test equipment. Global warming potential values the following table includes the 100year time horizon global warming potentials gwp relative to co2. Hydrofluorocarbons, currently used as refrigerants in airconditioning systems, are potent greenhouse gases, and their contribution to climate change is projected to increase. Freon refrigerants 4 introduction background chlorodifluoromethane r22 or hcfc22 has been used as a refrigerant in various refrigeration, industrial cooling, air conditioning, and heating applications for over five decades. Linde strongly advocates the use of refrigerant gases with zero ozone depletion potential and fully supports the phase out of hcfcs. Odp ozone depletion potential degree to which a substance can degrade the ozone layer. The next generation refrigerant will require essentially zero. On top of that there is the direct ozone depletion potential gwp due to refrigerant emission.
Refrigerants are regulated as hazardous materials by the us epa and carb, due to their ozone depleting ability and powerful greenhouse gas potential. R427a like other gases such as r407c is a zeotrope. Refrigerants r407c and r407a properties, uses, storage. Refrigerant retrofits unit 9 test flashcards quizlet. Comparison of characteristics of some refrigerants 17 table 5. Ozone depleting potential of some substances 14 table 4. Review and quiz terms and acronyms used in this training material class i substance ozone depleting chemical with an ozone depletion potential greater than 0. In the 1980s, scientists observed a thinning of the ozone layer over antarctica, and people began thinking of it as an ozone hole.
Which of the following refrigerants is a cfctype refrigerant. Chlorine interacts with ozone, converting it into oxygen and taking away its beneficial properties. Development of synthetic refrigerants continued in the 1950s, when partially chlorinated refrigerants hydrochlorofluorocarbons or hcfc were introduced, including r22. Sep 17, 2014 global warming potential measurement of global warming done in relation with co2,where co2 has gwp 1 lower the value of gwp better the refrigerant few examples are given below. Stratospheric ozone depletion and hvac refrigerants. Amount of damage to the ozone layer a given chemical can cause compared to trichlorofluoromethane, which is given a value of 1.
Fellow ashrae mcquay international staunton, virginia usa 1 what is a refrigerant. R4a tetrafluoroethane is an environmental nonozone depleting refrigerant, the cooling capacity and efficiency and r12 is very close, they were regarded as longterm alternative to r12. Mar 03, 2015 what refrigerant has the lowest ozone depletion. Refrigerant product information opteon xp10 r5a is a nonozone depleting, low global warming potential gwp hydrofluoroolefin hfo based refrigerant developed to replace r4a in positive displacement, direct expansion, mediumtemperature commercial and industrial chillers, as well as flooded andor centrifugal chillers. The potential for a single molecule of the refrigerant to destroy the ozone layer. Fire fighter training material development workshop. Gwp global warming potential degree to which a greenhouse gas ghg traps heat in the atmosphere. Refrigerant r290 propane is a hydrocarbon with zero ozone depletion potential odp and very low gwp value of less than 20. All refrigerants use r11 as a datum reference where r11 has an odp 1. R404a began seeing usage in 1996 after the phase out of cfc r502 due to its ozone depletion potential. Historically, chlorofluorocarbons cfcs were used extensively as refrigerants in the air conditioning and refrigeration industries. The global warming potential gwp is the relative measure of the.
In most cases no timeconsuming circuit rinsing is required. Candidate alternatives for r22 are being evaluated by a consortium of manufacturers in a project called. R404a is a ternary refrigerant blend consisting of the hfc r125 fortyfour percent, hfc r143a fiftytwo percent, and hfc r4a four percent. Odp values are used to provide a simple way to compare the relative ability of various ods to destroy stratospheric ozone. Environmental impact of refrigerants information daikin. R404a has been approved by many refrigeration compressor and system manufacturers for. R12 cfc refrigerants retrofit to hfc r4a with insignificant. Ozone depletion potential refers to the potential at which the ozone is depleting. It mandates that all refrigerants with odp will be phased out for new equipment by january 1, 2020.
Global warming potential of various refrigerants 18 table 6. Dichlorodifluoromethane r12 is a colorless gas usually sold under the brand name freon12, and a chlorofluorocarbon halomethane cfc used as a refrigerant and aerosol spray propellant. Ozone depletion potential article about ozone depletion. Theres a future for natural refrigerants by monika witt chairwoman of eurammon the question as to how to prevent food from going off is probably as old as humanity itself. Environmental policy is causing a shift from the current refrigerants used in appliances to a new class that pose fire hazard to occupants and emergency responders.
The american society of heating, refrigerating, and airconditioning engineers ashrae is an international leader in the field of refrigeration and air conditioning. Likewise, this rule does not affect the requirements for equipment containing ozone depleting substances. According to the montreal protocol, the odp of refrigerants should be zero, i. R11 high chlorine content gwp is 4000 r22 low chlorine content gwp is 1700 r4a no chlorine content gwp is 0 34. R4a is the refrigerant, which does not destroy the ozone layer, assigned for the substitute of r12 in the medium temperature units.
Chlorodifluoromethane r22, for example, has an odp of 0. The refrigerant impacts on the environment are evaluated with the ozone depletion potential odp and the global warming potential gwp. Way back in the stone age, people knew that food could be kept for longer in the cold, and stored meat and fruit in cool caves protected from heat and the sun. Physicochemical properties of various refrigerants 20 table 8. Refrigerants and cfcs a major cause of ozone layer depletion. Up to two points are awarded where it is demonstrated that hvac refrigerants in use have an ozone depletion potential odp of zero or where no refrigerants are used, as follows. The search for refrigerants with low global warming potential gwp to replace more harmful hfcs is continuing. R290 owns many advantages such as excellent thermodynamic properties. While the future evolution of the ozone layer depends largely on the abundances of ozone depleting sub stances, changes in climate arising from natural and anthropogenic causes are likely to also play an impor. Calculating ozone depleting potentials odp introduction the number of single component refrigerants with different thermodynamic properties suitable for different types of equipment is limited. Ozone depletion potentials odps were a very important measure in the formulation of the montreal protocol and its amendments. Zero ozone depletion potential replacement for r22. Human activities are the main reason for its depletion. Additional research has shown that ozone depletion occurs over every continent.
Refrigerants 1this is a summary of the most commonly used refrigerants. The ar5 values are the most recent, but the second assessment report 1995 and fourth. Evidence suggests that recent accelerated warming of the earths surface is the result of increased concentrations of heat. R410a is a nonozone depleting binary blend of two hfc refrigerants, comprising 50% of r32 and 50% of r125 by percentage of weight, it has no chlorine content, and only a modest global warming potential. Hydrofluoroolefin hfo based mixed gases having low gwp value were investigated as alternatives to different four refrigerants used commonly in refrigerating and air conditioning equipments. All the investigated refrigerant mixtures consist of zero ozone depletion potential. Furthermore, natural refrigerants stand out not only by being environmentfriendly the global warming potential of ammonia is zero and that of carbon dioxide and hydrocarbons is negligibly small but above all by being energy efficient.
The event was held on 5th september 2018 in quincy, massachusetts. The less the value of the odp the better the refrigerant is for. Through its mission to advance the arts and sciences of heating, ventilating, air conditioning and refrigerating to serve humanity and promote a sustainable world. Epa regulations and international treaties prescribe a time table to phase out these.
Refrigerants can thus also be ranked according to their impact on the stratospheric ozone layer the ozone depletion potential, odp or as greenhouse gases the global warming potential, gwp. Limited options for lowglobalwarmingpotential refrigerants. Cfc 11, or r11 has the maximum potential amongst chlorocarbons because of the presence of three chlorine atoms in the molecule. R111, 2 global warming potential 100 year, ipcc 4th assessment report, 2007. Odp, or ozone depletion potential, the montreal protocol focused on phasing out cfcs and hcfcs. Oct 04, 2016 hey guys, refrigerants is nothing but. Even though hfcs have a zeroodp, in some cases it has a global warming potential highgwp. Refrigerants typically used in commercial equipment r11, r12, r1 are the worst offenders and the refrigerant used in home air conditioners r22 is a relatively minor offender. The regulation for the management of high global warming potential refrigerants for stationary sources carb. Global warming potential gwp is a measure of how much a given mass of a gas contributes to global. These are the proceedings of the flammable refrigerants. Common refrigerants and their ozone depletion potential odp and global warming potential gwp are indicated below. Indicators for quantitative comparison of the various substancesareodp8ozonedepletionpotentialandgwp9 global warming potential, which are closely related to their atmospheric lifetime alt 10.
Working fluids in refrigeration cycles undergoes phase transition in cycles mostly before going to subject topic first of all we divide all refrigerants in following categories. Pdf the use of natural refrigerants in refrigeration and. On a worldwide basis, the most widely used hcfc refrigerant is r22 which has a low ozone depletion potential 5. The environmental guideline for ozone depleting substances odss and halocarbon alternatives does not cover the production, importing or exporting of new, unused odss and halocarbon alternatives.
One class of potential replacement refrigerants exhibit relatively low gwp but mild flammability i. Ozone depletion potential of different refrigerants. Refrigerant atmospheric lifetime years ozone depletion potential odp global warming potential gwp 100 year cfc no more cfc. The current generation of refrigerants, hydrofluorocarbons hfcs, have zero ozone depletion potential. Which type of refrigerant has the highest ozone depletion. American society of heating, refrigerating and air. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext.
Currently the major refrigerant is switching to hydrofluorocarbons hfcs which has zero ozone depletion potential zeroodp. However, r410a has a high global warming potential of 2088, higher than that of r22. This continues to this day and at this juncture, just after the adjustment of the montreal protocol to achieve an early phase out of hcfcs, the last major group of ozone depleting substances with high global warming potential, we might miss another opportunity unless we are watchful. It was designed to provide benefits in efficiency and system size by increasing system pressure and. Halogenated hydrocarbons, especially chlorofluorocarbons cfcs, are a major cause of ozone layer depletion because of the amounts of chlorine atoms that are part of their makeup.
The left side, compound gauge blue and the right side, highpressure gauge red, are attached to the manifold to measure system pressures. R12 cfc refrigerants retrofit to hfc r4a with insignificant ozone depletion potential. Second, because of its superior thermodynamic properties, ammonia as a refrigerant requires less energy than other refrigerants when used in large industrial systems. While analyses and system performance tools have shown that hfc refrigerant blends offer certain performance, capacity. Epa section 608 preparatory manual esco institute 2018 7 tion gauge manifold set one of the most important tools for an hvacr technician is the gauge manifold set. Refrigerants that have a low ozone depletion potential odp will, in turn, have a high total equivalent warming impact tewi. In the early 1970s, it was discovered that cfc and hcfc refrigerants breakdown the ozone layer. Refrigerants r402a, r402b, and r404a properties, uses.
This table is adapted from the ipcc fifth assessment report, 2014 ar5i. The consideration of these refrigerants continues to come under question due to the environmental concerns caused from ozone depleting potential odp, global warming potential gwp, energy efficiency, total equivalent warming impact tewi and life cycle climate performance lccp. The use of natural refrigerants in refrigeration and air conditioning systems. Ozone depleting potential odp is the ratio of the impact on ozone caused by a chemical compared to the impact of a similar mass of cfc11. Refrigerants having nonzero odp have either already been phasedout e. These activities are controlled under federal regulations by environment canada. Add r427a, with an initial charge of 95% of the original weight. Pdf refrigerant types, issues, trends and future options. In the present study, a comparison was considered about some characteristics of new generation low gwp value gases most of which are at the trial stage. Hydrocarbons as refrigerants an overview request pdf.
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