Policylegislation on fgases and alternatives two environmental frameworks. The antarctic ozone hole, as it came to be known, made depletion of. 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. Nextgeneration low global warming potential refrigerants. A compounds ozone depletion potential odp is shown as its equivalent in chlorine odp of a chlorine molecule 1. In terms of refrigerant charge sizes, there are two basic criteria. Environmental ranking of refrigerants is of need in many instances. Systems designed for r410a can take advantage of its ability to use smaller components, making it a key refrigerant for domestic and light air conditioning equipment. Calm, resource, ozone, and global warming implications of refrigerant selection for large chillers, paper icr07e1535, proceedings of the 22nd international congress of refrigeration, beijing, 2126 august 2007, chinese. Stratospheric ozone depletion is a global threat to the balance of nature resulting in a decreasing concentration of ozone particles in the upper atmosphere. Low gwp refrigerant ozonedepletion potential zeroodp. 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.
Federal register protection of stratospheric ozone. A refrigerant global warming potential gwp is based on a ratio of the refrigerants. R4a tetrafluoroethane is an environmental nonozonedepleting refrigerant, the cooling capacity and efficiency and r12 is very close, they were regarded as longterm alternative to r12. Even though hfcs have a zeroodp, in some cases it has a global warming potential highgwp. Merging the transition to next generation hvac refrigerant. The primary disadvantage of r407c is the large temperature glide due to the blend of the specific refrigerants. Cfcs were replaced with hcfcs, which have lower ozonedepletion potential odp, or with. In 1987 a conference was held where it was decided to phase out the production of cfcs and develop the suitable substitute refrigerants that have no ozone depletion potential.
Pdf causes of ozone layer depletion and its effects on. Stratospheric ozone depletion and hvac refrigerants. The first is that they are not reactive chemically speaking, which means they survive long enough in the atmosphere to drift up into the. However, r410a has a high global warming potential of 2088, higher than that of r22. Common refrigerants and their ozone depletion potential odp and global warming potential gwp are indicated below. It went into effect in 1987, first targeting cfcs, then hcfcs. The factory charge in a split system, using r22 shows 6 lb. Amolea at2 has no ozone depletion potential, has less global warming potential than our existing asahiklin ae3000 series products, is nonflammable, and is. 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.
Linde strongly advocates the use of refrigerant gases with zero ozone depletion. The regulation for the management of high global warming potential refrigerants for stationary sources carb. Management of ozone depleting substances refrigerants. When did it become unlawful to intentionally release class i and class ii refrigerants into the atmosphere. Amount of damage to the ozone layer a given chemical can cause compared to trichlorofluoromethane, which is given a value of 1. Relative value that indicates the potential of a substance to destroy ozone gas as compared with the potential of chlorofluorocarbon11 cfc11 which is assigned a reference value of 1. Refrigerants are regulated as hazardous materials by the us epa and carb, due to their ozone depleting ability and powerful greenhouse gas potential. Find out information about ozone depletion potential. Chlorodifluoromethane r22, for example, has an odp of 0. In most cases no timeconsuming circuit rinsing is required. Ozone depletion potential article about ozone depletion.
Refrigerants have varying atmospheric lifetimes, ozone depletion potentials and global warming potentials. This is a relative indication of the effect of the. Ozone depletion potentials odps were a very important measure in the formulation of the montreal protocol and its amendments. Indicators for quantitative comparison of the various sub. It operates at higher pressures than many other refrigerants, and so cannot be used to retrofit r22 systems.
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. 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. Refrigerants r454c r455a r1234yf ozone potential depletion odp following en3781 version 2016 0 0 0 global warning potential gwp. Zero ozone depletion potential replacement for r22. Causes of ozone layer depletion and its effects on human. Ozone depletion potential of different refrigerants. Due to the fact that cfcs damage the ozone layer, environmental groups and the montreal protocol call for halting cfc production.
Normal ozone ozone layer depletion and its effects. These substances are effective ozonedepleters for two reasons. The effects on the industry of the actions to reduce ozone depletion and global warming are now apparent. All of the refrigerants use r11 as a datum reference, and thus r11 has an odp of 1. Resource, ozone, and global warming implications of. Both appear superior in safety performance and environmental properties to any other available alternatives. Refrigerant types, issues, trends and future options. Odp is defined as the integrated change in total ozone per unit mass. Impact of refrigerants r1234yf, r455a, r454c on the.
Add r427a, with an initial charge of 95% of the original weight. In the last two centuries, human ingenuity made it. These radiations can cause severe diseases in humans such as skin cancer, eye damage and genetic mutations etc 9. Global warming potential is the potential of a substance in trapping. Some halocarbons ozone depleting substances, or odss deplete the ozone layer, while others greenhouse gases, or ghgs are thought to contribute to global warming. Product information sorted by product type and name type product r number. 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. Cfcs are listed by the epa as class i ozone depleting substances 1923 what chemical family is the basic building block for most modern refrigerants. It is more sustainable to choose refrigerants with low atmospheric lifetimes as well as low ozone depletion and global warming potentials, since the longer a compound is present in the atmosphere, the more damage it can cause. Ozone depletion and global warming are two major environmental concerns with serious implications for the future development of the refrigerationbased industries. At present the research is now mainly focused on refrigerants with zero ozone depletion potential odp and less gwp, which are termed as fourth generation. Ozone depletion potential odp is the potential for a single molecule of the refrigerant to destroy the ozone layer. 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.
Pdf thermodynamic analysis and effects of replacing hfc by. Ozonedepleting substances ods contain various combinations of the chemical elements chlorine, fluorine, bromine, carbon, and hydrogen and are often described by the general term halocarbons. Highperformance, lowglobalwarming refrigerants for. The negative influence of refrigerants on the climate and the immediate environment in terms of their higher global warming potential gwp and ozone depletion potential odp has prompted this study. Currently the major refrigerant is switching to hydrofluorocarbons hfcs which has zero ozonedepletion potential zeroodp. The r4a was the first chlorinefree refrigerant discovered 2. Epa estimates that the proposed revisions will prevent damage to the stratospheric ozone layer by reducing emissions of ozonedepleting refrigerants by approximately 116 metric tons per year, weighted by the ozonedepletion potential odp of the gases emitted. 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. Volkmar hasse, gtz proklima, germany preface volkmar hasse, gtz proklima i. A blend that contains different hfcs is considered an hfc refrigerant. Find non ozone depleting refrigerants related suppliers, manufacturers, products and specifications on globalspec a trusted source of non ozone depleting refrigerants information. Refrigerants containing chlorine or bromine contribute to the breakdown of the ozone layer see figure 5.
A and b, have attractive physical properties, zero ozone depletion potential, low global warming potential, and low total equivalent warming impact tewi. R410a is an hfc blend designed for new r22 applications. Terms in this set 27 ozone blank is a numeric value assigned to refrigerants to compair how harmful they can be to the ozone. Natural refrigerants sustainable ozone and climatefriendly alternatives to hcfcs introduction dr. Ozone depletion is affecting the human health and environment negatively, as it allows the penetration of uv radiations to reach the earth. Low gwp refrigerants can contribute greatly to greenhouse gas mitigation. Pdf refrigerant types, issues, trends and future options. Ozone depletion potential odp the depletion of the ozone layer is driven primarily by the catalytic action of chlorine, fluorine and bromine in compounds, which split up ozone molecules o 3, thus destroying the ozone layer. Recently, the ozone potential odp and global warming potential gwp have become the most important criteria in the development of new refrigerants apart from the refrigerant cfcs and hcfcs, both of which have high odp and gwp due to their contribution to ozone layer depletion.
Substances with high global warming potential gwp are a key concern. Odp is ozone depletion potential of with re ference to cfc r11 as 1. Which of the following refrigerants have the lowest ozonedepletion potential odp. A halogenated refrigerant is a refrigerant that has been made. Ozone depletion and global warming overview page 1 of 5 halocarbons are chemical compounds containing carbon, one or more halogens, and sometimes hydrogen. Refrigerants for automotive air conditioning systems. Most of the cfcs and hcfcs causing ozone layer depletion and greenhouse effect are already being phased out. 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. Thus, a substance with odp of 2 is twice as harmful as cfc11. Ranking are based upon ozone depletion potential, global warming potential, and. However, halogenated refrigerants possess comparatively poor environmental properties with respect to ozone depletion potential odp and global warming potential gwp. In 1985, the scientists published an article in nature announcing that stratospheric ozone over antarctica was reduced 40% in september, the end of the austral winter.
Ozone is a variant of oxygen, the ozone molecule having three atoms of oxygen. The second is the maximum charge size, and this refers to the upper limit that the allowable charge size can reach. R427a like other gases such as r407c is a zeotrope. Global warming potential gwp is a measure of how much a given mass of a gas contributes to global warming. Ozone depletion potential odp of a chemical compound is the relative amount of degradation it can cause to the ozone layer. 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. Hydrocarbons, specifically methane and ethane 1924 what is a halogenated refrigerant. This refers to the maximum mass of refrigerant for a given occupied room size. This factor is one for r11, as it has maximum potential to destroy the ozone layer. Ozonedepleting substances ozone layer protection us epa. The ozone depletion potential odp of a chemical compound is the theoretical relative degradation that this compound inflicts on the ozone layer, by the destruction of ozone in the upper atmosphere.
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