Refrigerators and freezers are true endurance athletes working 24 hours a day, 365 days a year to deliver a constantly cold environment. With older, less energy efficient models this can involve significant expense, and so buying a new appliance is often worthwhile on the basis of the energy savings alone. Anyone thinking about buying a new appliance should take account of the model’s energy efficiency class (as a rule of thumb, the more + signs, the more energy efficient the appliance). This is good news for your wallet and good news for the environment. If you want to find out precisely how energy efficient an appliance is, you will need to look at the EU energy label, and this also tells you lots more besides.

In 2010, a new European Directive on the energy labelling of household refrigeration and freezer appliances came into force. Ever since, the standardised EU energy label has provided consumers, in all 28 EU member states, with details about the power consumption of refrigerators and freezers as well as all sorts of other information. The label has a language-neutral design with pictograms conveying the information and this makes it easy to compare different models and different manufacturers.

The label uses standardised colours and provides consumers with information about:

  • The energy efficiency class: individual classes are indicated by coloured arrows and by using the letters A to D, with class A being the most energy efficient. Dark green represents highly efficient appliances; red represents appliances that are less energy efficient. Plus (+) signs after the class letter (e.g. A +++) provide a more precise indication of the energy efficiency. The more + signs, the more energy efficient the appliance. For example, A++ appliances are 21 percent more energy efficient than A+ appliances, whereas A+++ appliances are as much as 48 percent more energy efficient. Liebherr is pushing the bar even higher with the CBPesf 4043 combination fridge-freezer; this model is about 20 percent more energy efficient than the current A+++ threshold, consuming only 130-kilowatt hours of electricity per year (kWh per annum).

Further information on the EU energy label:

  • A milk carton with an amount in litres to indicate the total storage volume of all the refrigeration compartments.
  • A snowflake with an amount in litres to indicate the total storage volume of all the freezer compartments.
  • A speaker icon indicating the noise level (sound performance) during operation in decibels, dB(A). All Liebherr household appliances have a decibel level of between 32 dB(A) and 44 dB(A). Generally, when it comes to ‘noise’, an increase or reduction in the ‘sound pressure level’ equates to a louder or quieter perceived noise respectively. A person’s hearing threshold depends on the frequency, specified in Hertz (Hz). Approximately 2 kHz, is 0 decibels. However, this does not mean that 0 dB equates to ‘completely silent’. This can be explained using the logarithmic correlations of the sound pressure level calculation. Most people don’t hear anything below the quiet threshold (see diagram).

A person’s ability to hear changes with age. The quiet threshold curve indicates that our sense of hearing has different levels of sensitivity at different frequencies. The closer the hearing threshold to lower sound levels, the more sensitively our hearing reacts to the corresponding frequency range. The threshold indicates that our hearing responds most sensitively in the frequency range of 2 kHz to 5 kHz.

This can be clearly seen from the lowering of the hearing threshold. In this area, only a very low noise level is required to create an hearing sensation. From a frequency of 10 kHz, the threshold starts to climb sharply. The sound level must be correspondingly increased to create an auditory sensation with the same subjective level of perceived noise as in the lower range between 2 kHz and 5 kHz. The same applies to the area of lower frequencies.

The perceived volume therefore depends on not only the sound pressure level but also upon the frequency. The perception of ‘volume’ and ‘sound pressure level’ are not the same. Noises with the same sound pressure but different pitches are therefore perceived at different volumes. In particular, deep and very high-pitched tones are perceived by the human ear as quieter. To take this into account, the noise levels measured are specified in A-rated decibels, dB(A). The tones of a trumpet and the noise of a digger on a construction site have approximately the same sound level, but are perceived entirely differently.

Several examples for comparison:

Siren: 150 dB(A) Pneumatic hammer: 120 dB(A) Digger/trumpet: 115 dB(A) Discussion: 70 dB(A) Liebherr WKEes553: 32 dB(A) Ticking of a watch: 20 dB(A) Rustling of leaves, light breathing 10 dB(A)

Returning to saving energy… as already said, anyone buying a new appliance should note the energy efficiency label, choose an appliance in a high energy efficiency class, and then sit back and enjoy the benefits of a lower electricity bill. These days, most of the appliances that are available on the market are in efficiency classes A+++, A++ or A+ because, since 1st July 2012, the Ecodesign Regulation 643/2009 has prohibited the market launch of compressor-operated refrigerators/freezers in an energy efficiency class of A or lower. Despite this, retailers can still sell off appliances brought to market before this date.

The following two examples show how much you can save using Liebherr appliances: the Liebherr CBNPes 3756 fridge-freezer with energy efficiency class A+++ uses 67 percent less energy than a 12-year-old model. The built-in IKP 1650 uses an even more impressive 69 percent less electricity than the older model KI 1840.

Do you have any questions about energy efficiency and the energy label? Write to us or use the comment function at the bottom of the post.