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BACKGROUND
Under the 1992 amendments to the Montreal Protocol, industrialized countries have been implementing a gradual phase-out of chlorofluorocarbons (CFCs), hydrochloro-fluorocarbons (HCFCs) and other substances that deplete the ozone layer, which shields the earth from excessive ultraviolet radiation. In the U.S., this phase-out is regulated under Title VI of the Clean Air Act as amended in 1990 (CAA). HCFCs are classified as Class II Ozone Depletion Substances by the U.S. Environmental Protection Agency (EPA), and are widely used as refrigerants in air conditioners, including transit industry use in buses, trolleys and rail vehicles. Under an established cap based upon prior use, the U.S. must reduce the amount of HCFCs imported and produced nationwide by 35 percent in 2004. Further limitation milestones are scheduled for 2010, 2015, 2020 and a final phase-out in 2030.
PHASE-OUT MILESTONES
Annual HCFC Milestones:
- January 1, 2004 - 35% reduction in import and production
- January 1, 2010 - 65% reduction in import and production
- January 1, 2015 - 90% reduction in import and production
- January 1, 2020 - 99.5% reduction in import and production
- January 1, 2030 - total phase-out.
FUTURE CONDITIONS
In the U.S., HCFC–22 (also called R-22) is used extensively in the transit industry as a refrigerant. On January 1, 2010, R-22 will be allowable for use only in refrigeration and air conditioning equipment constructed prior to this date. All new rolling and stationary stock constructed after this date, will be required to contain an acceptable Class II substitute refrigerant, although existing equipment may continue to use R-22 or may be retrofitted to an approved alternative. The HCFC reduction will be enforced through EPA’s HCFC Allowance Allocation System. This program rations individual importers and manufacturers to limits based upon their highest importation and production of HCFCs respectively between 1994 and 1997. Consequently, the transit industry may soon be facing twin problems of refrigerant scarcity and the practicality of using multiple refrigerants in a complex fleet.
ALTERNATIVE REFRIGERANT AVAILABILITY
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In order to assist industry in the changeover to substitutes with zero ozone depletion potential (ODP), EPA has developed the Significant New Alternatives Policy (SNAP) Program, which evaluates new and existing products in eight industrial sectors that historically relied on high volumes of ozone depleting chemicals. CFC and HCFC substitute refrigerants are assessed for ODP, global warming potential, volatility, exposure toxicity and other safety and environmental aspects. Substances submitted by industry for review are evaluated for acceptability and are published in the Federal Register and on the EPA website. Under the EPA’s SNAP Program, an R-22 alternative must be reviewed and tested before it may be used in new equipment or in retrofits of old equipment, and unacceptable substitutes that pose adverse effects to human health or the environment are illegal to use. |
R-22 at a transit maintenance facility during a 2004 environmental audit. |
Not all air conditioning equipment is compatible across alternative refrigerant types. For example, lubricants compatible for use with HCFCs may not be appropriate for use with a zero ODP replacement refrigerant. Also, it remains illegal to knowingly vent HCFC refrigerants during maintenance and service. EPA recommends careful steps in retrofitting existing equipment to substitute cooling products and, under Section 608 of the CAA, requires certification (Type II and Universal) of all technicians on HCFC-22 refrigerant recovery procedures and systems. Transit operations employing these technicians must certify to their regional EPA office that they have obtained and are properly using certified refrigerant recovery equipment. These requirements reinforce the prohibition against intentionally venting R-22.
CONSIDERATIONS IN CHOOSING AN ALTERNATIVE
Transit managers and service technicians will need to consider a number of factors when choosing an R-22 replacement including:
- Product – the substitute must be approved by EPA
- Practicality – the overall ease of use across the organization
- Efficiency – the costs and benefits based on the capacities, efficiencies and pressures related to the individual application
- Versatility – the capability of working across the range of R-22 based infrastructure and equipment
- Safety – the implementation of a design with both human and operational safety in mind
- Availability – the ease of operating with existing, readily available refrigerants.
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