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HISTORY OF AIR CONDITIONING & HEATING IN AUTO

n around since the 1970's in specialty applications, is a ceramic element plus a heat transfer device made of metal fins, wired to the vehicle's power supply (alternator); the ceramic is barium titanate (BaTiO3) (Curhan, 1990, p. 56). By contrast to "metallic resistance heaters" (the current standard), PTC ceramic heaters heat quickly to a constant temperature (as much as 210(C), have a variable rather than a constant power demand -- depending on ambient temperature, and regulate temperature of the passing air automatically as a function of their inherent material properties rather than with a thermostat (Curhan, 1990, p. 56). These heaters also tend to have a power draw near 40 volts, as opposed to 12-14 volts in the metallic resistance heaters, so a boosted power supply or second alternator may be necessary (Curhan, 1990, p. 57). Moreover, a variable speed fan may be necessary, because the temperature of the wired ceramic element varies with the air flow rate across it; hence, this flow rate must be modulated with "fan control," plausible wiring for which is shown in a Curhan diagram (Curhan, 1990, p. 57). Costs are not given, but decreases in heating time to attain the "comfort zone" (30 to 40(C) are claimed to be three-to-five to one (two to three minutes vs. ten) over conventional heaters (Curhan, 1990, p. 59).

HISTORICAL AIR CONDITIONING DEVELOPMENTS

The earliest history of air-conditioning equipment applied to public places has been thoroughly detailed by Nagengast (1993). It seems that theaters ("movie houses") of the earliest years of the 20th Century were the sites of the first broad exposure of the public to air conditioning, the 1920's having been the boom years of these developments; although the concept was debuted at the 1904 St. Louis World's Fair, and a refrigerated brine plant was introduced at the City Theater in Rio de Janeiro, Brazil, in July 1909 (Nagengast, 1993, p. S49).

After early industry's fits...

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HISTORY OF AIR CONDITIONING & HEATING IN AUTO. (1969, December 31). In LotsofEssays.com. Retrieved 21:38, March 28, 2024, from https://www.lotsofessays.com/viewpaper/1681975.html