Energy labels for refrigerators and freezers In many
countries in the world a labelling system for electrical appliances is in
place. Such a system could work as follows. The energy efficiency index EEI =
C/ Cref, where C (in kWh) is the annual electricity consumption
(under test conditions) and Cref (in kWh) is the reference annual
electricity consumption. The latter is calculated as follows:
where Vr is refrigerator volume (in litres); Vf is
freezer volume (in litres); α and β are constants. The term β is
introduced to compensate for the fact that smaller equipment has a relatively
larger energy use than larger equipment. The EEI is converted to a label,
according to the classification Note that this exercise is based on existing
labelling systems, but numbers are fictitious and the system description is
highly simplified.a list of refrigerators and refrigerator-freezer combinations
with measurements of energy use. Classify this equipment in the classes A+++ to
10.2 Standard and actual energy use
To determine the specific energy consumption of
refrigerators, their electricity consumption is measured under the following
standard conditions: ambient temperature 25 °C; door always closed; empty.
a. In practice, there are three sources of heat that need
to be cooled away. What are these?
b. Which options can you think of to improve the
efficiency? In what categories of Section 10.3 can these be included?
c. How do the different options for energy efficiency
improvement affect the electricity consumption under the standard test
procedure and under practical conditions? Are there options of which the effect
is overstated or understated under the standard test procedure?
d. What adaptations to the standard test procedure would