Development and Implementation of Survey Techniques for Assessing In-Situ Appliance Efficiencies

A study was conducted to develop and field-test audit procedures for use in a large survey of in-situ appliance efficiency indicators. The appliances concerned were refrigerators, gas and electric water heaters, central air conditioners, and central gas furnaces. The efficiency indicators measured were compared to the manufacturer's rated values as determined by the California appliance standards procedures. The field test involved 61 homes during summer 1986 and winter 1986-1987. Appliances were submitted to one-day short-term efficiency tests and one-week long-term monitoring of energy use and operational characteristics. Accuracy objectives were met for refrigerators, for the recovery efficiency of water heaters, and for central gas furnaces. The water heater standby loss and air conditioner efficiency audit procedures cannot be considered practical audit procedures to be included in a large survey of appliance efficiency. The audit procedures for a large survey would consist of one-day testing of the water heater, air conditioner, and furnace, and one-week monitoring of the refrigerator. Costs for the audit procedures recommended for the large survey are given. The audit procedures field-test produced the following appliance efficiencies results. Water heater recovery efficiencies were 7% lower than their rated values on average, while air conditioner efficiencies were more than 20% lower than their rated values on average. Refrigerator consumption was 12% higher than rated on average, and furnace efficiencies were within 1% of the rated values.