Automobile air conditioning

1953 Chrysler Imperial with factory trunk mounted "Airtemp"

Automobile air conditioning systems cool the occupants of a vehicle in hot weather, and have come into wide use from the late twentieth century. Air conditioners use significant power; on the other hand the drag of a car with closed windows is less than if the windows are open to cool the occupants evaporatively. There has been much debate on the effect of air conditioning on the fuel efficiency of a vehicle. Factors such as wind resistance, aerodynamics and engine power and weight have to be factored into finding the true variance between using the air conditioning system and not using it when estimating the in actual fuel mileage. Other factors on the impact on the engine and an overall engine heat increase can have an impact on the cooling system of the vehicle.

History

A company in New York City in the United States, first offered installation of air conditioning for cars in 1933. Most of their customers operated limousines and luxury cars.^[1]

The Packard Motor Car Company was the first automobile manufacturer to build air conditioners into its cars, beginning in late 1939 (at the start of the 1940 model year).^[2] These air conditioners were optional, and cost US$274 (equivalent to about US$4,000 in 2007).^[3] The system took up half of the entire trunk space, was not very efficient, and had no thermostat or independent shut-off mechanism.^[4] The option was discontinued after 1941.^[5]

Chrysler Airtemp

The 1953 Chrysler Imperial was the first production car in twelve years to actually have automobile air conditioning, following tentative experiments by Packard in 1940 and Cadillac in 1941.^[6] Walter P. Chrysler had seen to the invention of Airtemp air conditioning back in the 1930s for the Chrysler Building, and had ostensibly offered it on cars in 1941-42, and again in 1951-52, but none are known to have been sold in the latter form until the 1953 model year. In actually installing optional Airtemp air conditioning units to its Imperials in 1953, Chrysler beat Cadillac, Buick and Oldsmobile which added air conditioning as an option in the 1953 model year.

Airtemp was more sophisticated and efficient than the complicated rival air conditioners of 1953. It recirculated, rather than merely cooled, the air inside the vehicle, and it was also the highest capacity unit available on an automobile. It was also simple to operate, with a single switch on the dashboard marked with low, medium, and high positions, which the driver selected as desired. The system was capable of cooling a Chrysler from 120 degrees to 85 degrees in about two minutes, and of completely eliminating humidity, dust, pollen and tobacco smoke at the same time. Since it relied on fresh air, and drew in sixty percent more of it than any contemporary system, Airtemp avoided the staleness associated with automotive air conditioning at the time. It was silent and unobtrusive. Instead of plastic tubes mounted on the package shelf as on GM and on other cars, small ducts directed cool air toward the ceiling of the car where it filtered down around the passengers instead of blowing directly on them, a feature that modern cars have lost.^[6]

Nash integrated system

In 1954 the Nash Ambassador was the first American automobile to have a front-end, fully integrated heating, ventilating, and air-conditioning system.^[7][8] The Nash-Kelvinator corporation used its experience in refrigeration to introduce the automobile industry's first compact and affordable, single-unit heating and air conditioning system optional for its Nash models.^[9][10] This was the first mass market system with controls on the dash and an electric clutch.^[11] This first true refrigerated air conditioner system was also compact and easily serviceable with all of its components installed under the hood or in the cowl area.^[12]

Combining heating, cooling, and ventilating, the new air conditioning system for the Nash cars was called the "All-Weather Eye"^[13] This followed the marketing name of "Weather Eye" for Nash's fresh-air automotive heating and ventilating system that was first used in 1938.^[12] With a single thermostatic control, the Nash passenger compartment air cooling option was described as "a good and remarkably inexpensive" system.^[14] Entirely incorporated within the engine bay, the combined heating and cooling system had cold air for passengers enter through dash-mounted vents.^[10] Nash's exclusive "remarkable advance" was not only the "sophisticated" unified system, but also its $345 price that beat all other systems.^[15]

Automatic climate control

Most competing systems used a separate heating system and an engine-mounted compressor, driven off of the crankshaft of the engine via a belt, with an evaporator in the car's trunk to deliver cold air through the rear parcel shelf and overhead vents. General Motors made a front mounted air conditioning system optional in 1954 on Pontiacs with a straight-eight engine that added separate controls and air distribution. The alternative layout pioneered by Nash "became established practice and continues to form the basis of the modern and more sophisticated automatic climate control systems."^[16]

Growth in demand

The innovation was adopted quickly, and by 1960 about 20% of all cars in the U.S. had air-conditioning, with the percentage increasing to 80% in the warm areas of the Southwest.^[17] American Motors made air conditioning standard equipment on all AMC Ambassadors starting with the 1968 model year, a first^[18] in the mass market with a base price starting at $2,671.^[19] By 1969, 54% of the domestic automobiles were equipped with air conditioning, with the feature needed not only for passenger comfort, but also to increase the car's resale value.^[3]

The future

It is claimed that a new type of air-conditioning for automobiles called TIFFE (Thermal systems Integration For Fuel Economy)^[20] will come into production in 2015. It is said to reduce gasoline consumption by 15%.^[21]

References

External links

• "Air Conditioners for Your Car." Popular Science, April 1969, pp. 117–132, detailed drawings.