Environmental Engineering Reference
In-Depth Information
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Do not select a room temperature that is higher than necessary. Each extra
degree consumes around 6% more heat energy.
■
Turn down the heat at night and when no one is at home.
■
Close blinds, shutters and curtains at night.
■
Avoid leaving windows open all the time to air rooms; instead briefl y open
windows completely a few times a day to bring in fresh air.
■
Do not enclose, block or hide radiators behind curtains.
Even minor investments can help reduce energy use considerably. Appropriate
measures can include draught-proofi ng windows and doors, and upgrading thermo-
stat valves.
In terms of saving energy, a tremendous amount can be achieved in new-build
homes or planned renovations. In the case of three-litre and passive houses, heating
requirements can be slashed to as little as one-tenth of what is normally needed in
conventional houses. The heating required in an average apartment block in Central
Europe is around 150 to 200 kilowatt hours per square metre of living area per year
(kWh/(m
2
a)). Old buildings with poor insulation can even show usage values of
over 300 kWh/(m
2
a). A new - build still needs around 100 kWh/(m
2
a). In contrast, a
three-litre house only needs 30 kWh/(m
2
a), whereas a passive house gets by with
even less than 15 kWh/(m
2
a) (Figure 3.6 ). These fi gures can vary for other climate
regions. However, in warmer countries there is a higher demand for cooling than
for heating. The energy-saving possibilities with optimal insulation are similar.
Figure 3.6
Comparison of heating requirements and heat loss in houses with different
insulation standards in kilowatt hours per square metre of living area per year in Central
European climates (kWh/(m
2
a)).
A Low-Energy House is Not Necessarily a Low-Energy House
Anyone interested in building a low-energy house will fi rst have to grapple
with a variety of different terms and concepts that sometimes confuse even
the experts. The following should help to unravel some of this confusion.
Low - energy house -
These are especially well insulated buildings that have low heating
requirements. Most countries have not legally specifi ed this concept. Normal new-builds
are often unjustifi ably labelled as being low-energy or energy-saving buildings.
