A geographic representation of saturations of ceiling fans based on data from the RASSes. White areas indicate a lack of data for that region.

Many utilities survey their customers to learn more about the buildings and the occupants in their service areas. These surveys--usually called "residential appliance saturation surveys," or RASSes--ask for the number and types of appliances present, the number of people living in the home, and sometimes personal information.

The RASSes are also used to collect information about the presence of conservation measures such as wall and ceiling insulation, weatherstripping, multipane windows, and water flow restrictors. Building Energy Analysis Group researchers Alan Meier and Brian Pon gathered RASSes from more than 100 utilities for recent research on the nation's progress in residential retrofit. This compilation represents nearly 80 million residential customers, or approximately 80% of the nation's households. Average saturation levels of conservation measures were calculated from these RASSes.

The principal advantage of using RASSes is that each RASS surveys a large number of consumers. When data from the RASSes are aggregated nationally or regionally, their sample size is far greater than that of analogous nationwide surveys, which typically survey only a few thousand customers. Another advantage is the low cost of obtaining them: usually only a letter and a phone call are required to complete the survey. Unfortunately, the inconsistent questions and wording among the RASSes collected from the various utilities make it difficult to aggregate the data.

The figure above shows the saturation of ceiling fans across the nation. Although most utilities did not ask their customers if they had ceiling fans, enough did ask that the variation among regions is detectable. In fact, the saturation of ceiling fans appears to be very dependent on region. Saturation levels are 50% or greater in the South and in the Mississippi and Ohio River valleys. The use of ceiling fans in the homes of these regions would influence the energy use of conventional air conditioners.

The figure below geographically represents the saturation levels of water-heater blankets. The saturation levels in various regions appear to have little correlation to climate, ranging from 8% in central Texas to 56% in one Pacific Northwest service area. The latter area's utility conducted a free water-heater wrap program in 1989. Evidently, this program was highly successful.

A geographic representation of saturations of water-heaters based on data from the RASSes. White areas indicate a lack of data for that region.

--Brian Pon and Alan Meier

Brian Pon
(510) 486-6829
Alan Meier
(510) 486-4740
Building Energy Analysis Group
Energy Analysis Program