per year). By 1969 the thing to buy, if budget permitted, was a frost-free freezer (1,761 kwhr). The increase in size and convenience is undeniable, but so is the increase (180 percent) in energy use. Increases occurred elsewhere as well. The room cooler (935 kwhr) became the window air conditioner (1,389 kwhr). The wringer washer (45 kwhr) became the automatic clothes washer (103 kwhr). (See Table 3-24.)

These figures on appliance energy consumption are averages. Just as there are variations in design and purchase price among competing appliances, so are there variations in the amount of energy different appliances require to perform essentially the same task or service. For example, some room air conditioners are more efficient than competing models—i.e., they use less energy than others having the same cooling capacity.