Shrinking Bills on Shrunken Fridges

Small auto-defrost refrigerators have traditionally been among the least efficient fridges on the market, sometimes consuming as much electricity as units 50% larger. People who don't need a large fridge or who simply don't have space for a larger, efficient unit have had to pay high energy bills for their apartment-sized fridge.

To solve this problem, the New York Power Authority (NYPA) made an arrangement with the New York City Housing Authority (NYCHA). NYPA encouraged manufacturers to develop a more efficient small refrigerator. General Electric responded to the challenge by developing a new small fridge with an Energy Guide label that predicted annual energy use of 498 kWh per year, 20% lower than called for under the 1993 federal standards. NYPA purchased 20,001 of these efficient fridges and installed them in public housing units run by NYCHA (see "Efficient Refrigerators for Apartments" HE May/June '96, p. 11).

NYCHA pays the energy bills for the units. It kept some of the refrigerator energy savings and used some of the remaining money to pay NYPA for the fridges. This fulfilled their shared-savings agreement. So that both NYPA and NYCHA would know how much energy the fridges were saving, researchers from Pacific Northwest National Laboratory (PNNL) and Synertech Systems were brought in to monitor energy use.

The researchers discovered that actual energy use was about 30% higher than the Energy Guide label predicted. This was not a surprise, because most apartments are kept significantly warmer than single-family homes, and a refrigerator's energy use climbs rapidly as the kitchen air temperature rises. This phenomenon has long been suspected, but this study is the first to document its effects in public housing.

The new refrigerators were larger than the ones they replaced (14.4 ft³ versus 12.6 ft³) and had auto defrost. Nevertheless, they consumed about 600 kWh per year less than the old units.

The actual savings depended on temperature setting inside the refrigerator. General Electric shipped the refrigerators with the temperature set at 5 (on a scale of 1-9). At this setting, the freezer and fresh food compartment temperatures were much colder than needed. Almost 100 kWh per year could be saved simply by adjusting the refrigerator thermostat to warmer--but still safe--temperature settings. To capture these savings, NYPA began resetting the thermostats in new refrigerators and distributed a reminder to the residents.

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