Environmental Engineering Reference
Figure 3.5 Tiny, dimmable light bulbs open up possibilities to all kinds of uses.
Electric hot water boilers are not only ineffi cient but also expensive. Anyone who
has an electric boiler should switch it off when leaving the house for long periods.
A considerable amount of energy can also be saved with large electrical appliances,
such as washing machines, dishwashers, refrigerators and freezers. Effi ciency
should be an important criterion, especially in the selection of new appliances.
Energy effi ciency-class labels and the consumption values included with these labels
provide an indication of the economy of use with different appliances.
Unfortunately, the energy - effi ciency classes indicated are not always that clear at
fi rst glance. The washing machines, dryers and dishwashers with the highest effi -
ciency are those with an A rating. With refrigerators and freezers the effi ciency scale
has been extended to include classes A+ and A++. The most effi cient appliances in
this category therefore have an A++ label. A person who chooses a refrigerator with
a class A++ rating over a reasonably priced appliance in energy-effi ciency class B
can save 30 euros in electricity costs per year. With a 10-year lifetime for the appli-
ance, this adds up to 300 euros. The higher price of effi cient devices and appliances
often pays for itself over the lifetime of the item. And the environmental benefi ts
are greater. Compared to one in class B, an appliance in class A++ can save up to
a ton of carbon dioxide.
If someone is not aware of how much energy a device or appliance is consuming,
he or she can use an energy-saving monitor (available for hire or purchase) to test
which appliances are energy wasters. It is advisable to take particularly ineffi cient
appliances out of service as quickly as possible.
A savings potential also exists in the way household goods are used. If a refrigerator
is standing right next to a stove, it has to work harder because of the stove's heat.
Refrigerators with poor ventilation and iced-up freezer compartments also use a
large amount of extra energy. A lid on a pot when cooking can save an appreciable
amount of energy, as can a pressure cooker. Selecting the lowest temperature