Odp defined the odp, or ozone depletion potential, is the potential for a single molecule of the refrigerant to destroy the ozone layer. Pdf ozone depletion potential of different refrigerants. The odp of chemicals is the measure of how much it causes the ozone layer to degrade as compared to trichlorofluoromethane cfc11, which has a baseline odp of 1. Ozone depletion potential odp of a chemical compound is the relative amount of degradation it can cause to the ozone layer. The first generation of refrigerants included substances such as hydrocarbons, ammonia, and carbon dioxide. Refrigerants are regulated as hazardous materials by the us epa and carb, due to their ozone depleting ability and powerful greenhouse gas potential. Since 2010, phaseout regulations became effective in other countries as well, for instance in the usa. A viable lowgwp candidate must possess a number of other attributes 6, including zero or very low ozone depletion potential, chemical stability within the refrigeration system, thermodynamic. They have been controlled by the montreal protocol since 1987 because of their ozone depleting potential and high global warming potentials. Halocarbon potential contributions to ozone depletion and global warming exhibit 2 provides odps for the class i and class ii odss.
Class i substances have a higher ozone depletion potential and have been completely phased out in the u. In order to reduce the depletion of ozone and reverse the climate change effects, the european union legislation 2014 and paris accord 2016 are strongly emphasizing the phasing out of the use of harmful synthetic refrigerants. Global warming potential gwp is a measure of how much a given mass of a gas contributes to global. Other countries are following suit and driving the market toward hfcfree. Choice of natural refrigerants makes no net addition of the greenhouse gases ghg in the environment. New refrigerants designation and safety classifications. This is measured by their ozone depletion potential odp. 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. Because of their ozone depletion characteristics, cfcs have been phased out and hcfcs are in the process of being phased out. Odp ozone depletion potential odp is a measure of the potential of a substance to harm the ozone layer if released into the atmosphere.
Indicators for quantitative comparison of the various substancesareodp8ozonedepletionpotentialandgwp9 global warming potential, which are closely related to their atmospheric lifetime alt 10. All of the refrigerants use r11 as a calibration and thus r11 has an odp of 1. Ozonedepleting substances ozone layer protection us epa. Common refrigerants and environmental safety thermal systems. Ozone depletion potential of different refrigerants and their solution. Indicators for quantitative comparison of the various sub stances are odp 8 ozone depletion potential and gwp 9. Ozone depletion and global warming potential of thermal. Different substances break down ozone more rapidly than others. Highgwp refrigerants california air resources board. Like us on facebook to stay uptodate with industry news, events and free members resources. Types of refrigerants and their environmental impact. Linde strongly advocates the use of refrigerant gases with zero ozone depletion potential and fully supports the phase out of hcfcs.
Refrigerant recovery and recycling epaapproved section 609 program for motor vehicle air conditioning mvac service now with r1234yf this booklet is distributed free of charge and is not to be sold. 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. The ozone depletion potential odp of a refrigerant represents its effect on atmospheric ozone, and the reference point usually adopted is odp 1 for the cfc r11. Research and development roadmap for nextgeneration low global warming potential refrigerants introduction 9 1 introduction 1. The regulation for the management of high global warming potential refrigerants for stationary sources carb. Refrigerant types, issues, trends and future options. Hfcs which has zero ozone depletion potential zeroodp. They have a very low or zero global warming potential and zero ozone depletion potential. Substances with high global warming potential gwp are a key concern.
Refrigerants r407c and r407a properties, uses, storage. The third category is alternative cycles that include absorption systems, and use of. A complete analysis of the relative harms of ozone depletion and global warming is beyond the scope of this report, because the full implications of both anthropogenic effects are not known. Ozone depletion potential odp there are also some chemical compounds, which include refrigerants, that contribute to the depletion of the ozone layer. Enhanced refrigerant management and leednc v4 ea credit 6 john m. Gwps including indirect effects of ozone depletion have been estimated fo r a variety of halocarbons cfcs, halons, hcfcs, etc. Low gwp refrigerants can contribute greatly to greenhouse gas mitigation. The higher the gwp value, the more that particular gas warms the earth compared to carbon dioxide. The absolute highest gwp on hydrocarbon refrigerants that i could find was twentyfive.
Limited options for lowglobalwarmingpotential refrigerants. Highglobal warming potential highgwp refrigerants include all ozonedepleting substances and any refrigerant with a gwp of 150 or higher. In general, all refrigerants are characterised by two numbers. Odp is the ratio of ability of a substance to degrade ozone, to that of chlorofluorocarbon11 cfc11, which therefore, has a value of 1. The net gwps of halocarbons depend strongly upon the effectiveness of each compound for ozone destruction. Odp is ozone depletion potential of with re ference to cfc r11 as 1. Refrigerants and their application presented by thomas e. They also have good energy efficiency, but are flammable and can form an explosive mixture with air if a leak occurs. Types of refrigerants and their environmental impact gineersnow.
But through domestic and international action, the ozone layer is healing and should fully recover by about 2065. Under this circumstance, natural refrigerants such as nh3, hc and co 2 are thus obtaining more and more favour because of their very low environmental impact. Fellow ashrae mcquay international staunton, virginia usa 1 what is a refrigerant. R427a like other gases such as r407c is a zeotrope. 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. A number of alternative refrigerants have been developed and still many more new are being developed. Some of these refrigerants are entirely new ones, while the others are the mixture of two or more refrigerants. Cfcs are generally characterised by a big odp value, because they contain chlorine, which is accused of heavily contributing to the ozone. Natural and synthetic refrigerants, global warming. Ozone depletion potential is measured relative to cfc11 and it represents. The antarctic ozone hole is a dramatic demonstration of the environmental impact caused by emissions of cfcs, hcfcs and other ozone depleting substances ods that release chlorine and bromine as they break down in the stratosphere. Epa later added hbfcs and methyl bromide to the list by regulation.
Enhanced refrigerant management and leednc v4 ea credit 6. Refrigerants for commercial refrigeration applications. After a series of rigorous meetings and negotiations, the. Pdf refrigeration and airconditioning play a vital role in domestic and industrial applications. The montreal protocol unep, 1997 states the phasing out of cfcs and hcfcs as. In some categories of the leed rating system, minimum energy performance and fundamental refrigerant management are included as a prerequisites, the intent is to establish a minimum level of energy efficiency for the building system and reduce ozone depletion potential, gwp, and support early compliance with epa montreal protocol. S with a few exceptions, this means no one can produce or. Global warming potential vs ozone depletion potential.
Refrigerants having nonzero odp have either already been phasedout e. According to the montreal protocol, the odp of refrigerants should be zero, i. The ozone depletion potential odp of a chemical compound is the relative amount of degradation to the ozone layer it can cause, with trichlorofluoromethane r11 or cfc11 being fixed at an odp of 1. R404a is a ternary refrigerant blend consisting of the hfc r125 fortyfour percent, hfc r143a fiftytwo percent, and hfc r4a four percent. The low ozone depletion potential of r22 compared to cfc11 chlorofluorocarbon 11 and cfc12 and its excellent refrigerant properties have helped facilitate the transition away from cfcs. Ozone depletion potential of different refrigerants.
Introduction under the montreal protocol on substances that deplete the ozone layer, article 7 of the protocol requires all parties, both developing countries also called article 5 countries and developed countries. In 2019, nasa announced that the ozone hole over antarctica was the smallest ever since it was first discovered in 1982. Significant new alternatives policy snap program us epa. Low gwp refrigerant global warming, together with ozone layer depletion have been two of the top ten global environmental concerns since 1970s. Learn vocabulary, terms, and more with flashcards, games, and other study tools.
The dilemma, therefore, is that some refrigerants cause more ozone depletion than others, but the most ozone friendly refrigerants cause more global warming. Although these refrigerants have no ozone depletion potential, they have a negative impact on global warming when these refrigerants leak to atmosphere during system operation. Regulation in the united states regarding refrigerants has been centered on two factors, ozone depletion potential odp and global warming potential gwp. The odp of chemicals is the measure of how much it causes the ozone layer to degrade as compared to trichlorofluoromethane cfc11, which has a. Zero ozone depletion potential replacement for r22.
The treatment by leed of the environmental impact of hvac. 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. Refrigerant selection to reduce climate impact edge buildings. Low gwp refrigerant ozonedepletion potential zeroodp. Chlorodifluoromethane r22, for example, has an odp of 0. Cfcs class ii substance ozone depleting chemical with an ozone depletion potential.
Measurements of chlorine within the antarctic ozone hole from nasas aura satellite. This table provides up to date internationally recognised data on the ozone depletion potential and global warming potential of the gases, as well as an easy reference summary of their impact. Most of the cfcs and hcfcs causing ozone layer depletion and greenhouse effect are already being phased out. Nextgeneration low global warming potential refrigerants. This website addresses stratospheric ozone issues, including the science of ozone depletion, epas regulatory approach to protecting the ozone layer, epaapproved alternatives to ozone depleting substances, and sun safety. Although these refrigerants have no ozone depletion potential, they have a negative impact on global warming when these refrigerants leak. The following chart shows the ozone depletion potential odp and global warming potential gwp values for common cfcs, hcfcs, and hfcs. Ozone depletion potential an overview sciencedirect topics. By following the criteria in the rating systems, the selected refrigerants can help the project achieve points toward green building status. Cfc11 and cfc12 with the longest atmospheric lifetime and highest ozone depletion potential were phased out first, followed by the hydrochlorofluorocarbons. This is the process of ozone depletion and has already caused a substantial amount of damage to the ozone layer.
The greatest concentration of ozone are found from 12 km to 50 km above the earth forming a layer in the stratosphere which is called the ozone layer. Environmental drivers there are two factors important to the discussion of the environmental impact of refrigerants. Although these refrigerants have zero ozone depletion potential odp and minimum global warming impact due to direct emissions but there are safety and environmental factors associated with them that would limit their widespread use as refrigerants. Refrigerant product information opteon xp10 r5a is a non ozone 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. Gwp values for ozone depleting substances can range, for. Add r427a, with an initial charge of 95% of the original weight. Ozone layer depletion odp and global warming potential gwp have become one of the most important global issues. Common refrigerants and their ozone depletion potential odp and global warming potential gwp are indicated below. 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. The odp is the ratio of the impact on ozone of a chemical compared to the impact of a similar mass of cfc11. Ozone depleting substances refrigerant reclaim australia.
Product information sorted by product type and name. Refrigerants and cfcs a major cause of ozone layer depletion. Ozone depletion potential odp and global warming potential gwp. It is also a common component in many hfc refrigerant blends and is used. In the united states, ozone depleting substances ods are regulated as class i or class ii controlled substances. Which of the following refrigerants contains chlorine. Firstand secondgeneration refrigerants were composed of natural refrigerants and hydrocarbons hcs, both of which do not impact the environment, have low gwp, and zero ozone depletion potential. The other hydrocarbons were all between five and zero. Refrigerants containing chlorine or bromine contribute to the breakdown of the ozone layer see figure 5. Graph showing the ozone depletion potential odp, or potential damage that each substance could cause to the ozone layer, relative to the chlorofluorocarbon, cfc11. In most cases no timeconsuming circuit rinsing is required. Pdf refrigerant types, issues, trends and future options. Chapte r ozone depletion potentials, global warming.
Compared to halogenated refrigerants, hydrocarbons like isobutane r600a and propane r290 offer several advantages. Cfc 11, or r11 has the maximum potential amongst chlorocarbons because of the presence of three chlorine atoms in the molecule. The ozone depletion potential odp of a chemical compound is the relative amount of. One chlorine atom has the potential to destroy more than 100,000 ozone molecules. Hydrocarbon refrigerants have zero ozone depletion potential and have a very low global warming potential. Product information sorted by product type and name type product r number. Which type of refrigerant has the highest ozone depletion potential. R111, 2 global warming potential 100 year, ipcc 4th assessment report, 2007. The green globes rating system accounts for ozone depletion, global warming and leak detection. Class i substances listed in the clean air act caa include cfcs, halons, carbon tetrachloride, and methyl chloroform. The primary disadvantage of r407c is the large temperature glide due to the blend of the specific refrigerants.
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