Detroit sources estimate that the auto industry will sell more than 1,000,000 air conditioned cars this year. Add to this an estimated 250,000 non-factory or independent units and you come up with a figure that hardly represents a status symbol. In fact, air conditioned ears in many areas of the country are no longer considered a luxury but rather a necessity. This is especially true among fleets, particularly in the South.

The air conditioning boom has been going on for several years, A 1,000,000 sales year for factory in­stalled units would represent approximately 15 per cent of all the cars produced by Detroit. Last-year 12 per cent of all cars produced were equipped with air conditioning. This compares with 8 per cent in 1961 and 7 per cent in I960.

Originally the only market for air conditioned cars was in the luxury car field. Cadillac, for example, has equipped more than 500,000 cars with air con­ditioning since it first offered the feature in 1953. While the luxury cars still lead the way in air con­ditioned cars-Cadillac is selling 67.4 per cent of its cars with air conditioning compared with 60.3 per cent a year ago; Lincoln-Continental 80.7 per cent against 72.2 per cent; and Imperial 64 per cent vs. 60 per cent-the medium-price and low price-cars are making great strides.

Chevrolet, for example, is putting air conditioning units in 12 per cent of all cars produced. This com­pares with 7.5 per cent a year ago. The 1963 Corvair percentage is down to 2 per cent from 2.5 per cent last year but the Chevy II is running at 3 per cent against 2.2 per cent in 1962. Pontiac is placing air conditioning in 24 per cent of its standard cars and in 6 per cent of its Tempest models. This compares with last year's figure of 19.6 per cent for the standard Pontiac and 3.6 per cent for the Tempest.

The impact of air conditioning in fleet-type cars is readily apparent viewing the 73,000 Chevy II, Comet, Corvair, Falcon, F-85, Lancer, Lark, Rambler, Special and Tempest models that were factory-equipped with air conditioning last year. This was more than had power brakes or power windows.

In the low price field, a total of 235,000 cars were equipped with air conditioning at the factory. This includes Chevrolet, Dart, Fairlane, Ford, Meteor and Plymouth.

Sales in the medium-price field -- Buick, Chrysler, Dodge 880, Mercury, Oldsmobile and Pontiac  -- totaled 322,000 units while the luxury cars-Cadillac, Imperial and Lincoln-accounted for 125,000 factory installed air conditioning units in 1962.

REASONS FOR SURGE

One of the chief reasons for the gaining popularity of air conditioned cars is price. Several years ago air conditioner prices of $400 to $700 were not un­common.  Today, factory-installed or field installed units can be purchased for between $240 and $450, depending upon the make of car. It: can be expected that as volume increases the price of auto air con­ditioners will continue to drop.

A second reason for the gaining popularity of air conditioning is performability. When air conditioning first made its debut on the automotive scene, faulty design, poor installation, inexperienced mechanics, hard-to-get replacements and other problems often arose to plague the car owner and rob him of the driving comfort he thought he was buying.

When originally offered as optional equipment, factory installed units were of the "tack-on" type of installation comprising of components similar to a home window unit. The controls were bolted to the underside of the instrument panel. The factory-in­stalled units of today are generally installed into the vehicle much like a central heating system. The modern systems combine air conditioning and heater into a single unit, making it possible to heat con­ditioned air. The dehumidified and dust free air is then distributed at the desired temperature through the outlets into the car.

Great improvements have also been made in the independent or "hang on" type units. Originally field-installed units reached almost to the floor of a car, stealing valuable leg room in the front passenger com­partment. Most units now are of the compact variety, hanging only three inches below the dash.

"Our sales so far are running 90 per cent ahead of last year and with orders running like they are we can't miss a 50 per cent gain for the year," said a spokesman for Frigikar Corp., a Dallas manufacturer that sold 35,000 units last year.

No longer do independent manufacturers offer a box that hangs under the dash, but instead custom installations for all makes of cars.

Factory installed units offered by the auto industry bring in fresh air and cool it. Most under-the-dash units recirculate air already in the car. These are highly effective in areas where it gets extremely hot. The fresh air types, which also provide for recircula­tion for maximum cooling, are more efficient for general use in all types of climate.

With either unit, the operation is similar to a house­hold refrigerator. The basic parts include an evapora­tor, condenser and compressor. Other components such as a compressor clutch, thermostatic control switch and valve enable the system to function au­tomatically and economically.

The compressor is mounted in the engine compart­ment and is driven by fan belts from the crankshaft-pulley through a clutch mounted on the compressor. The evaporator, consisting of cooling coils, is in­stalled in the passenger compartment on a hang-on unit, usually under the dash. In factory installed units, only an evaporator extension valve is on the passenger compartment. The condenser is usually mounted in front of the radiator. The principle that rapid evaporation, or expansion of gas after compression, causes a rapid absorption of heal: from sur­rounding materials is the basic physics of the system.