Types of Air-Conditioning Equipment * The difference between the 1978 and 1997 estimates is statistically significant at the 95-percent confidence level. Sources: Energy information Administration; 1978, 1987, and 1997 Residential Energy Consumption Surveys. That overall increase was the result of a very large increase in the use of central air-conditioning systems, an increase that more than offset a decline in the use of window/wall units. In 1978, the use of window/wall units exceeded the use of central systems by 10 percentage points (33 percent compared with 23 percent). By 1987, the percentages were about equal, and by 1997, there were nearly twice as many housing units using central systems as window/wall units (47 percent compared with 26 percent). Over the 1978-1997 period, each of the four Census regions experienced dramatic growth in the use of central airconditioning equipment (Figure 2.17). As would be expected, the South, with its warm climate, consistently had the highest percentage of housing units using central airconditioners, followed by the Midwest, the West, and the Northeast. Use of Appliances Over the two decades covered by the RECS, large increases in appliance use in U.S. housing units were observed. As shown earlier (Figures 2.7 and 2.8), Btu consumption for appliances increased from 23 million Btu per housing unit in 1978 (17 percent of all the Btu consumed) to 27 million Btu per housing unit in 1997 (27 percent of all the Btu consumed). Microwave ovens, dishwashers, freezers, clothes washers and dryers, and water-bed heaters were Energy Information Administration End Uses of Electricity Energy serves a wide range of household needs--space heating and cooling, water heating, refrigerators, lighting, and the operation of a variety of appliances for entertainment, health, and comfort. For 19 years, the Residential Energy Consumption Survey has estimated the contribution of each of those end uses to total energy consumption. The share and relative ranking of each end use represent how the total consumption of electricity or natural gas is distributed over the end uses. The other commonly used household energy sources (fuel oil, LPG, and kerosene) are used mostly for space heating, water heating, and cooking. The largest use of electricity in the average U.S. household is for appliances (including refrigerators and lights), which consume approximately two-thirds of all the electricity used in the residential sector (Figure 3.1, Table 3.1). Source: Energy Information Administration, Forms EIA-457A, B, C, E, and H of the 1997 Residential Energy Consumption Survey. Energy Information Administration Energy Use of Televisions and Videocassette Recorders in the U.S., Lawrence Berkeley National Laboratory, 1999. Notes: "Residual" includes appliances not listed, such as dehumidifiers, evaporative coolers, crankcase heaters, automatic drip coffee makers, irons, air cleaners, and a myriad of other small electrical appliances. "Residual" also includes errors that may be present in estimates of annual consumption. Totals may not equal sum of components due to independent rounding. This table does not reflect the interactive effects of appliance usage, especially when mixing the estimates from RECS with those from outside sources. For example, for a home with an electric oven, range, and a microwave, the use of the microwave may not add 132 kWh to the cooking consumption. For more discussion of this problem, see Appendix C, “End-Use Estimation Methodology." Sources: Energy Information Administration, Office of Energy Markets and End Use, Forms EIA-457A-C, E, and H of the 1997 Residential Energy Consumption Survey (RECS), RECS Public-Use Data Files; American Electric Power Service Corporation, and Southern California Edison. Energy Information Administration |