The regulation for the management of high global warming potential refrigerants for stationary sources carb. Characteristics of some new generation refrigerants with low. They also have good energy efficiency, but are flammable and can form an explosive mixture with air if a leak occurs. In most cases no timeconsuming circuit rinsing is required.
The need to find a long term solution calls for the use of natural refrigerants. Significant new alternatives policy snap program snap was established under section 612 of the clean air act to identify and evaluate substitutes for ozone depleting substances. Spanich, according to the german energy agency, the operation of ventilation and airconditioning systems accounts for around 20 percent of all energy consumed by commercial buildings. Alternatives to ozone depleting refrigerants in test equipment. Impact of charge degradation on the life cycle climate performance of a residential air conditioning system an evaluation of the environmental impact of different commercial supermarket refrigeration systems using low global warming potential refrigerants. Low gwp refrigerant ozonedepletion potential zeroodp. Ozonedepleting substances ozone layer protection us epa. A novel modular tool for life cycle climate performance lccp based. Chlorodifluoromethane r22, for example, has an odp of 0.
The environmental alternative to traditional refrigerants. A comparative study on the environmental impact of co2 supermarket refrigeration systems. R4a is widely used in automotive air conditioning and residential, commercial and industrial refrigeration systems, but also as a blowing agent for rigid. Hydroflourocarbons hfcs can be short and midterm replacements, but may not be permanent due to their high global warming potential gwp 5. Refrigerants and their environmental impact substitution. The ozone depletion potential odp of a refrigerant is the relative amount of depletion to the ozone layer it can cause. Currently the major refrigerant is switching to hydrofluorocarbons hfcs which has zero ozone depletion potential zeroodp. Common refrigerants and their ozone depletion potential odp and global warming potential gwp are indicated below. However, r410a has a high global warming potential of 2088, higher than that of r22. 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. Cfc 11, or r11 has the maximum potential amongst chlorocarbons because of the presence of three chlorine atoms in the molecule. Refrigerants and cfcs a major cause of ozone layer depletion. Refrigerants containing chlorine or bromine contribute to the breakdown of the ozone layer see figure 5. 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.
Natural refrigerants was developed as a joint effort between the national renewable energy laboratory nrel and cta architects engineers. Epa regulations and international treaties prescribe a time table to phase out these. R11 high chlorine content gwp is 4000 r22 low chlorine content gwp is 1700 r4a no chlorine content gwp is 0 34. Global warming potential gwp is a measure of how much a given mass of a gas contributes to global.
Nonozone depleting substances ods do not deplete the earths protective ozone layer. Apr 12, 2020 the ozone depletion potential odp of a refrigerant is the relative amount of depletion to the ozone layer it can cause. A refrigerant is a substance or mixture, usually a fluid, used in a heat pump and refrigeration cycle. Chlorine interacts with ozone, converting it into oxygen and taking away its beneficial properties. It has a high chlorine content and ozone depletion potential odp, and high global warming potential. For some background on ozone and depletion visit the site of the. 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. Desirable properties of refrigerants chemical engineering site. Refrigerants are regulated as hazardous materials by the us epa and carb, due to their ozone depleting ability and powerful greenhouse gas potential.
R404a has been approved by many refrigeration compressor and system manufacturers for use in new refrigeration equipment, such as food. Currently the major refrigerant is switching to hydrofluorocarbons hfcs which has zero ozonedepletion potential zeroodp. Calculating ozone depleting potentials odp introduction the number of single component refrigerants with different thermodynamic properties suitable for different types of equipment is limited. Even though hfcs have a zeroodp, in some cases it has a global warming potential highgwp. Systems with natural refrigerants need around 30% less energy.
R12 cfc refrigerants retrofit to hfc r4a with insignificant. Refrigeration systems using low global warming potential refrigerants. 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. R427a like other gases such as r407c is a zeotrope. The less the value of the odp, the better the refrigerant is for the ozone layer, and therefore the environment. R12 cfc refrigerants retrofit to hfc r4a with insignificant ozone depletion potential. Refrigerants and their environmental impact substitution of. Historically, chlorofluorocarbons cfcs were used extensively as refrigerants in the air conditioning and refrigeration industries.
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 search for refrigerants with low global warming potential gwp to replace more harmful hfcs is continuing. The refrigerator and air conditioning industries have started to address the future challenges. 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. Fluorocarbons, especially chlorofluorocarbons, became commonplace in the 20th century, but they are being phased out because of their ozone depletion effects. Natural refrigerants selecting and designing energyefficient commercial refrigeration systems that use low global warming potential refrigerants caleb nelson, chuck reis, eric nelson, james armer, rob arthur, richard heath, and james rono cta architects engineers boise, idaho adam hirsch and ian doebber. It was designed to provide benefits in efficiency and system size by increasing system pressure and. Products that normally contain ozone depleting substances should be replaced with functionally similar products that contain nonozone depleting substances. In the 2009 version, they were ea p3 and ea c4 respectively.
Hcfcs, therefore, have a lower ozone depletion potential. All of the refrigerants use r11 as a datum reference, and thus r11 has an odp of 1. Ozone depletion potential of different refrigerants. Ozone depletion potential odpr111 0 global warming potential rev 5th ipcc gwp co 21 depletion. Indicators for quantitative comparison of the various substancesareodp8ozonedepletionpotentialandgwp9 global warming potential, which are closely related to their atmospheric lifetime alt 10.
For each ods, this page provides the compounds atmospheric lifetime, ozone depletion. Add r427a, with an initial charge of 95% of the original weight. 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. R4a tetrafluoroethane is an environmental non ozone depleting refrigerant, the cooling capacity and efficiency and r12 is very close, they were regarded as longterm alternative to r12. Significant new alternatives policy snap program us epa. 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.
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. Mar 03, 2015 what refrigerant has the lowest ozone depletion. The program looks at overall risks to human health and the environment of existing and new substitutes, publishes lists and promotes the use of acceptable substances. The direction we are moving should normally lead to lower emissions of cfcs and hcfcs and increasing emissions of hfcs. Ozone depletion potential odp of a chemical compound is the relative amount of degradation it can cause to the ozone layer. 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. Halocarbon potential contributions to ozone depletion and global warming exhibit 2 provides odps for the class i and class ii odss. R22 finds its use in most residential and small commercial air conditioning systems whereas r 123 has.
Linde strongly advocates the use of refrigerant gases with zero ozone depletion potential and fully supports the phase out of hcfcs. In most cycles it undergoes phase transitions from a liquid to a gas and back again. 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. 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. Ranking are based upon ozone depletion potential, global warming. 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. 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 ozone depleting refrigerants like r22 are phased out. Refrigeration systems using low global warming potential refrigerants beshr et al. Stratospheric ozone depletion and hvac refrigerants. Many working fluids have been used for such purposes. The odp is the ratio of the impact on ozone of a chemical compared to the impact of a similar mass of cfc11.
This paper describes the technical approach and the primary lessons learned from the conversions completed prior to april i, 1994. Zero ozone depletion potential replacement for r22. Cfcs are one particular class of refrigerants and fire extinguishing mediums containing chlorine and fluorine atoms. Compared to halogenated refrigerants, hydrocarbons like isobutane r600a and propane r290 offer several advantages. The odp values are from table 15 of the scientific assessment of ozone depletion, 2002, a report of the world meteorological associations global ozone research and monitoring project. 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. Limited options for lowglobalwarmingpotential refrigerants. A refrigerant is a fluid that is used for heat transfer in a cooling system. 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.
For each ods, this page provides the compounds atmospheric lifetime, ozone depletion potential ozone depletion potentiala number that refers to the amount of ozone depletion caused by a substance. 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. This project was made possible with american recovery and reinvestment act of 2009 funds. Companies like honeywell are to looking into redesigning appliances like air conditioners and refrigerant applications that have a lower gwp. Enhanced refrigerant management and leednc v4 ea credit 6.
Airconditioning with natural refrigerants interview with thomas spanich, member of the board at eurammon, the european initiative for natural refrigerants mr. 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. A viable lowgwp candidate must possess a number of other attributes 6, including zero or very low ozonedepletion potential, chemical stability within the. Global warming potential gwp is a relative measure of how much heat a refrigerant traps in the atmosphere. R111, 2 global warming potential 100 year, ipcc 4th assessment report, 2007.
103 1541 836 1519 584 1264 498 1195 665 738 216 659 357 445 477 354 992 853 864 1045 613 1171 1295 443 801 64 685 241 597 969 222 758 170 356 573 845 245 1155 404 444 568 34