1938 A window air conditioner using Freon is marketed A window air conditioner using Freon is marketed by Philco-York. Featuring a beautiful wood front, the Philco air conditioner can simply be plugged into an electrical outlet. 1939 Air conditioning offered as an option in a Packard automobile Packard Motor Car Company markets an automobile with air conditioning offered as an option for $274. The refrigeration compressor runs off the engine, and the system has no thermostat. It discharges the cooled air from the back of the car. 1947 Mass-produced, low-cost window air conditioners become possible Mass-produced, low-cost window air conditioners become possible as a result of innovations by engineer Henry Galson, who sets up production lines for a number of manufacturers. In 1947, 43,000 window air conditioners are sold in the United States. For the first time, many homeowners can enjoy air conditioning without having to buy a new home or renovate their heating system.
1969 More than half of new automobiles are equipped with air conditioning More than half of new automobiles (54 percent) are equipped with air conditioning, which is soon a necessity, not only for comfort but also for resale value. By now, most new homes are built with central air conditioning, and window air conditioners are increasingly affordable. 1969 More than half of new automobiles are equipped with air conditioning More than half of new automobiles (54 percent) are equipped with air conditioning, which is soon a necessity, not only for comfort but also for resale value. By now, most new homes are built with central air conditioning, and window air conditioners are increasingly affordable. 1987 Minimum energy efficiency requirements set The National Appliance Energy Conservation Act mandates minimum energy efficiency requirements for refrigerators and freezers as well as room and central air conditioners. 1987 The Montreal Protocol The Montreal Protocol serves as an international agreement to begin phasing out CFC refrigerants, which are suspected of contributing to the thinning of the earth’s protective, high-altitude ozone shield. 1992 Minimum energy efficiency standards set for commercial buildings The U.S. Energy Policy Act mandates minimum energy efficiency standards for commercial buildings, using research and standards developed by the American Society of Heating, Refrigerating, and Air Conditioning Engineers.
At the turn of the century a few thousand people owned cars; in 1922 about 10 million did, and that number more than doubled in the next few years. Sharing their need for decent roads were fast-growing fleets of trucks and buses. And the federal government was thinking big. Congress had just authorized funds to help states create a 200,000-mile web of smooth-surfaced roads that would connect with every county seat in the nation. At the turn of the century a few thousand people owned cars; in 1922 about 10 million did, and that number more than doubled in the next few years. Sharing their need for decent roads were fast-growing fleets of trucks and buses. And the federal government was thinking big. Congress had just authorized funds to help states create a 200,000-mile web of smooth-surfaced roads that would connect with every county seat in the nation. It was just a beginning. Ahead lay engineering feats beyond anything Durant could have foreseen: the construction of conduits that can safely handle thousands of cars an hour and endure years of punishment by 18-wheel trucks, expressways and beltways to speed traffic in and around cities, swirling multilevel interchanges, arterial tunnels and mighty suspension bridges. Ahead, as well, lay a host of social and economic changes wrought by roads—among them, spreading suburbs, the birth of shopping malls and fast-food chains, widened horizons for vacationers, a revolution in manufacturing practices, and a general attuning of the rhythms of daily life, from errands to entertainment to the personal mobility offered by the car. Expansion of the network would also bring such indisputable negatives as traffic congestion and air pollution, but the knitting together of the country with highways has barely paused since the first automobiles rolled forth from workshops about a century ago. Rails ruled the transportation scene then. Like other developed nations, the United States had an intricate system of railroad tracks reaching to almost every sizable community in the land. Virtually all long-distance travel was by train, and electric trolleys running on rails served as the main people movers in cities. The United States also had more than 2 million miles of roads, but practically all were unsurfaced or only lightly layered with broken stone. A "highway census" performed by the federal government in 1904 found a grand total of 141 miles of paved roads outside cities. In rainy weather, travel in the countryside became nightmarish, and even in good conditions, hauling loads over the rough roads was a laborious business; it was cheaper to ship fruit by rail from California to an urban market in the East than to deliver it by wagon from a farm 15 miles away. As for anyone contemplating a lengthy drive in one of the new horseless carriages, an ordeal was in store. The first crossing of the continent by car in 1903 required 44 days of hard driving. By train the trip took just 4 days.
But cars had the irresistible advantage of flexibility, allowing drivers to go wherever they wanted, whenever they wanted, provided suitable roads were available. Efforts to accommodate motorized travel were soon launched by all levels of government, with particular emphasis on relieving the isolation of farmers. Beginning in 1907 the federal Office of Public Roads built experimental roads to test concrete, tars, and other surfacing materials. The agency also trained engineers in the arts of road location, grading, and drainage, then sent them out to work with state highway departments, which selected the routes and set the construction standards. Federal-state partnerships became the American way of road building, with the states joining together to harmonize their needs.
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