Document J1jy2EO8YbgwdezKeXQqDGaX

HEATING VENTILATING AIR CONDITIONING, GUIDE 1940 The.Sanitary Aspects of Air Conditioning, by C. P. Yaglou (American Journal of Public Health, February, 1938). Comfort of Surgeons and Operating Room Personnel, by James Govan (The Canadian Hospital, April, 1938). , , Cost, Data on Air Conditioning, by William E. Malm (Joint Committee onAir Conditioning, Skyscraper Management, July, 1938). Air Conditioning and the Surgical Patient, by W. McK. Craig (The Southern Surgeon, October, 1938, p. 462-4). . .. Some Practical Aspects of Air Conditioning in Hospitals, by Ancel Keys (Hospitals,' April, 1939). . A Trustee Considers Air Conditioning, by Charles F. Neergaard (Modern Hospital, July, 1939). Infection of Air, by W. F. Wells, M. W. Wells and Stuart Mudd (American Journal of Public Health, August, 1939). 584 Chapter 33 RAILWAY AIR CONDITIONING ' Passenger Car Ventilation, Quantity of Outside Air, Method of Air Distribution, Air Cleaning, Steam or Vapor Heating Equipment, Cooling Equipment, Humidity and Temperature Control, Power Supply, Installation and Operating Costs THE general principles of air conditioning as applied to buildings also apply to railway passenger cars, but due to space and weight limi tations and the severity of the service, equipment designed for stationary work is seldom suitable for car installations. Equipment for railway use must be safe, reliable, compact, light in weight, accessible for inspection and repairs, automatic in operation and in addition, have low initial, operating, and maintenance costs. To air condition a passenger car properly, ventilating, filtering, heating, cooling, humidifying, and control equipment must be provided together with an adequate power supply. Air from the interior of the car is mixed with air from the outside and passed through the air conditioning unit where it is heated or cooled, humidified or dehumidified and delivered to the interior of the car through suitable ducts and grilles. PASSENGER CAR VENTILATION In non air-conditioned cars, ventilation is accomplished by exhaust fans, roof ventilators,and open doors and windows. This practice provides an ample supply of outside air;biit'does not prevent the entrance of smoke, cinders,'and dirt. Quantify of Outside Air ' An average passenger car contains approximately 5000 cu ft of air and may seat as many as 80 passengers. The occupants are continually liberating heat, carbon dioxide, moisture, odors, arid some organic matter from their breath, skin and clothing. The heat and moisture can be removed by cooling and dehumidification, but the other constituents can be successfully handled only by proper ventilation and air cleansing. In the average car from 2000 to 2500 cfm should be circulated by the air conditioning unit. Some of this air may be recirculated, but a portion of it should always be brought in from the outside. The amount of outside air required depends upon the type of car, number of passengers, air temperature, humidity, odors, and whether or not occupants are smoking, and will vary from 15 to 90 per cent of the total air circulated. The per centage of outside air should be kept as low as possible to maintain the air in the proper condition in order to minimize the heat or cooling load. 585,