The optimum temperature in a fridge is approximately 4C and -18C in a freezer; power consumption increases dramatically when lower temperatures are maintained.
If you set your freezer at -25C the amount of refrigeration energy wasted can be as much as 10% which can cost (per year) an extra
If you bought a fridge-freezer today, it would use, on average, 50% less energy than a model available in 1990. By 2020 it is expected to be one of the most energy-efficient appliances in your home. This could mean savings of up to £44 per year.
Try not to over specify your fridge freezer. Differently sized A+ rated fridge freezers will use different amounts of electricity. For instance, a 157 litre fridge with an 87 litre freezer would cost about £42 a year to run, whereas a larger 230 litre fridge with a 97 litre freezer would cost £48 a year to run, costing an extra £6 = 20kg CO₂.
Choose the smallest possible model that suits your needs. One larger refrigerator is cheaper and more efficient to run than two smaller ones.
Buy an appliance with the best energy rating you can. The most efficient models carry the A+++ rating.
Chest freezers tend to be more energy efficient because less cold air escapes when the lid is opened as compared to when the door is opened of an upright freezer.
When buying a new fridge or freezer find out which refrigerant is used – Greenfreeze hydrocarbon technology is the most environmentally friendly according to Greenpeace.