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Researchers at the U.S. Energy Information Administration (EIA) have released interesting new data showing changes in household energy consumption. For decades, space heating and air conditioning accounted for more than half of the country’s residential energy consumption. Estimates from the 2009 Residential Energy Consumption Survey2009 (RECS) show that number has dropped to 48%, compared with 58% in 1993.

Efficiency, Documented

Chip Berry, RECS survey manager for EIA says the lower energy consumption can be attributed to a number of factors, not the least of which is more efficient heating and cooling equipment.

“Even if you compare as early as 1993, you’re seeing not just the percentage of energy use but the total amount of space heating coming down,” Berry tells REMODELING. “In terms of efficiency, federal standards started coming into place in the early 1990s, so any new construction was incorporating more efficient heating and cooling equipment, and homeowners who have replaced equipment since then are also benefitting from increased efficiency.”

According to EIA, total U.S. energy consumption in homes has remained relatively stable for many years as increased energy efficiency has offset the increase in the number and average size of housing units. The average household consumed 90 million (BTU) in 2009 based on the most recent RECS. This continues the downward trend in average residential energy consumption over the last 30 years, despite increases in the number and the average size of homes, plus increased use of electronics. Improvements in efficiency for space heating, air conditioning, and major appliances have all led to decreased consumption per household. Newer homes also tend to feature better insulation and other characteristics, such as double-pane windows, that improve the building envelope.

Tech Energy Consumption Rises

In addition to heating and cooling energy demand, the 2009 RECS looks at how much utility use is drawn for refrigeration, water heating, and other household appliances. Not surprisingly, the use of digital devices and home electronics is on the rise, and affects the RECS results.

In 2009, energy use for “other appliances, electronics, lighting, and miscellaneous,” increased by 50% over 1993 levels. According to the most recent survey, more than 50 million U.S. homes have three or more televisions, and 40% of homes have a DVR device. The use of DVRs has increased so sharply that their use wasn’t even tabulated for the previous RECS in 2005. EIA says that the increased popularity of DVRs is significant because the devices are replacing or supplementing VCRs and DVD players, which consume less energy per unit than DVRs.

Personal computing products also showed an increase in use from the 2005 RECS. More than three-quarters of households have a computer, and 39 million homes (35 percent) have at least two.

Detailed Research

Berry says that researchers began collecting data for the 2009 RECS in early 2010. In addition to more than 12,000 in-person interviews with homeowners nationwide, the agency takes detailed measurements of home sizes. Researchers then contact the utility companies used by the homeowners they interviewed and collect as much utility bill information as possible.

“Sometimes we’re not able to get all of the information we want from a supplier, so we take the information we get overall and annualize it for the year. That gives us a total consumption for each type of fuel, for each household,” Berry explains. “Then we combine that with expenditures data and answers to our homeowners survey and produce in-use estimates.”

Berry says that the 2009 RECS was the largest survey the EIA has conducted. As a result, more state-focused information is available compared with past years. “Historically, our samples were only big enough to report state data for the four largest states,” he says. “For 2009, we had samples large enough for 16 states” with the rest grouped into regions.

—Lauren Hunter, senior editor, REMODELING. twitter.com/LaurenHunter_HW