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Non-CFC Air Conditioning for Transit Buses
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English
Abstract
In the United Sates, more than 80% of transit city buses are air conditioned. Vapor compression refrigeration systems are standard for air conditioning buses and account for up to 25% of fuel consumption in the cooling season. Vapor compression devices use chlorofluorocarbons (CFCs), chemicals that contributes to Earths's ozone depletion and to global warming. Currently, evaporative cooling is an economical alternative to CFC vapor compression refrigeration for air conditioning buses. It does not use CFCs but is restricted in use to arid climates. This limitation can be eliminated by dehumidifying the supply air using desiccants. We studied desiccant systems for cooling transit buses and found that the use of a desiccant-assisted evaporative cooling system is feasible and can deliver the required cooling. The weight and the size of the desiccant system, though larger than vapor compression systems, can be easily accommodated within a bus. Fuel consumption for running desiccant systems was about 70% less than CFC refrigeration systems, resulting in payback periods of less than 2.5 years under most circumstances. This preliminary study indicated that desiccant systems combined with evaporative cooling is a CFC-free option to vapor compression refrigeration for air conditioning of transit buses. The concept is ready to be tested in a full prototype scale in a commercial bus.
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Authors
Citation
Pesaran, A., Parent, Y., and Bharathan, D., "Non-CFC Air Conditioning for Transit Buses," SAE Technical Paper 922459, 1992, https://doi.org/10.4271/922459.Also In
References
- AiResearch Manufacturing Co. 1980 Technical Report for Baseline Criteria and Air Conditioning System Specification Torrance, CA
- American Public Transit Association 1990 Transit Fact Book Washington, D.C.
- American Society of Heating Refrigerating and Air Conditioning Engineers 1991 HVAC Applications Handbook Atlanta, GA
- American Society of Heating Refrigerating and Air Conditioning Engineers 1989 Fundamentals Handbook Atlanta, GA
- Cargocaire Engineering Corporation 1984 Honeycomb Dehumidifier Performance and Selection Program Amesbury, MA
- Carrier Corporation 1987 Product Literature on Capri 280 Bus Air Conditioning Syracuse, NY
- Climatran Corporation 1989 Product Literature on Transit-Aire Englewood, CO
- Detroit Diesel Corporation 1984 Technical Specifications for the 6V-92TA Engine Detroit, MI Bennethum J.E. Detroit Diesel April 1991
- Kohler, J. Kuhn, B. Sonnekalb, M. Beer, H. 1990 “Numerical Calculation of the Distribution of Temperature and Heat Flux in Buses under the Influence of the Vehicle Air-conditioning System,” ASHRAE Transactions 96
- Lemke, R.D. 1975 An Evaluation of Transit Bus Air Conditioning Systems Society of Automotive Engineers Detroit, MI
- Harriman, L.G. 1990 The Dehumidification Handbook Munters Cargocaire Amesbury, MA
- Pesaran, A.A. Parent Y.O. Bharathan, D. October 1991 Non-CFC, Energy Efficient Air Conditioning for Transit Vehicles National Renewable Energy Laboratory, Golden, CO
- Suetrak 1984 Product Literature on Bus Air Conditioning Boulder, CO
- Thermo King 1987 Product Literature on T-Series Bus Air Conditioning Minneapolis, MN
- Urban Mass Transit Administration 1983 Evaporative Coolers for Transit Buses Washington, D.C.
- United States Air Force 1978 Engineering Weather Data: Facility Design and Planning Departments of the Air Force, the Army, and the Navy Washington, DC