Reducing domestic food waste by lowering home refrigerator temperatures

Abstract

Domestic refrigerators often operate at temperatures which are higher than ideal for chilled food storage, with several studies finding averages around 7°C. Reducing temperatures for example to 4°C could significantly extend storage lives, giving greater opportunity for use before disposal. However, the savings in costs and emissions associated with reduced waste must be balanced against those associated with increased energy consumption at lower temperatures. Based on published storage lives of foods which are currently refrigerated and UK waste statistics, reducing from 7°C to 4°C could save £162.9 m of waste annually, with associated emissions of 270,000 tonnes CO 2 e. Including certain foods which are not always refrigerated and removing others which do not benefit from refrigeration, the estimated savings increased to £283.8m and 578,383 tonnes CO 2 e. Based on experimental assessment, the costs and emissions associated with increased fridge energy consumption were considerably lower at £80.9 m and 367,411 tonnes CO 2 e.

The Use and Performance of Household Refrigerators: A Review

“…Few studies have addressed the effect of thermostat setting on energy consumption beyond acknowledging that reducing the thermostat setting will increase energy consumption. The energy consumption of fridge‐freezers is complicated by the fact that in most models, a single thermostat, sited in the refrigerator section, is used to control both the refrigerator and the freezer temperatures (Brown and others ). Adjusting this thermostat therefore affects not only the refrigerator temperature but also the freezer temperature, compounding the effect of temperature setting on energy consumption.…”

“…Saidur and others () found that energy consumption in a fridge‐freezer increased by about 7.8% for every degree reduction in operating temperature. Brown and others () calculated that lowering refrigerator air temperatures from a mean of 7 to 4 °C would result in an annual energy consumption increase of approximately 14.1 to 36.8 kWh per refrigerator (depending on the type of refrigerator).…”

“…Van Garde and Woodburne () found that when household refrigerator temperature increased from 2 to 20 °C, the amount of discards also increased proportionally. Brown and others () calculated that reducing mean refrigerator temperatures from 7 to 4 °C could save the U.K. £162.9 million of waste annually, with a reduction of associated emissions of 270,000 metric tons of CO 2 . Including certain foods that are not always refrigerated and removing others that do not benefit from refrigeration, the estimated savings increased to £283.8 million and 578,383 metric tons of CO 2 .…”

Thermal Performance, Usage Behaviour and Food Waste of Domestic Refrigerators in a University Student Community: Findings Towards Cities Sustainability

“…The refrigerators operated above 5.0ºC during 58% of the test, nevertheless representing a reduction of 2.0ºC compared to a similar study done two decades earlier. In fact, there are benefits in terms of storage live extend and consequently in food waste reduction reducing storage temperature of the refrigerator to 4ºC and promoting home freezing [6]- [8]. In an experimental study making use of temperature loggers placed at three shelf levels of 119 domestic refrigerators it was found that most users open the door around 20 times per day [9].…”

Thermal Simulation of the Fresh Food Compartment in a Domestic Refrigerator

“…On the other hand, it is known that the basic function of the refrigerator is storing fresh food and medicines, and this depends on the good performance of the refrigerator, which is closely linked to temperature distribution and air flow inside the compartments. Adequate temperature in these refrigerators could significantly extend the living cycle of food [3] and, inclusively, avoid the growth of certain types of bacteria [4]. In addition, the thermal behavior is influenced by the refrigeration system design, while the proper temperature distribution is achieved by a good interior design of the refrigerator.…”