Civil Engineering Reference
In-Depth Information
energy largely varies on the level of comfort required, climatic conditions and
operating schedules. At the end of buildings' service life, energy is required to
demolish the building and transporting the waste material to landfill sites and/or
recycling plants (Ramesh et al.
2010
).
3.2.2 Impact of Climate Change on Energy Use in the Built
Environment
Work on the subtropical climates had revealed an increasing trend of temperature
and summer discomfort over the past decades, and it was found that the anticipated
temperature rise could result in more cooling demand. More electricity use for air
conditioning would lead to larger emissions, which in turn would exacerbate cli-
mate change and global warming. Even in regions with severe cold climates where
the decrease in heating energy use could, in terms of final or delivered energy,
outweigh the increase in cooling, the impact of climate change on the overall
primary energy requirement and the environment would remain uncertain. This is
because heating is usually provided by oil- or gas-fired boiler plants, whereas
cooling relies on electricity-driven chillers (except gas-fired absorption systems).
In terms of carbon footprint, electricity tends to have a much lower overall effi-
ciency and higher CO
2
emissions per unit energy consumption. From a nationwide
energy and environmental perspective, it is important to be able to estimate the
magnitude of the likely changes in heating and cooling energy requirements due to
climate change in different climate zones. Broadly speaking, there are two main
approaches (Li et al.
2012
):
• Degree-days method. The degree-days concept is widely used for measuring the
influence of climate on heating and cooling requirements. Hekkenberg et al.
(
2009
) argues that socio-economic changes may alter the temperature depen-
dence pattern of energy demand in future years. However, to a good approxi-
mation heating and cooling energy requirements can be assumed to be
proportional to the HDDs and CDDs, respectively. In recent years, this method
has been used to assess the impact of climate change on regional energy demand
as well as energy consumption in the built environment in different parts of the
world. Pilli-Sihvola et al. (
2010
) chose five countries along the north-south
gradient: Finland, Germany, the Netherland, France and Spain. Their main
findings were as follows: in central and north Europe, the decrease in heating
due to climate warming would dominate, and in southern Europe climate
warming and the consequential increase in cooling and electricity demand
would outweigh the decreasing need for space heating.
• Building energy simulation technique. There had been a number of studies on
the impact of climate change on the built environment using sophisticated
building energy simulation tools to perform hour-by-hour computation of the
heating/cooling loads and corresponding energy use. Building energy simulation
is an acceptable technique for assessing the dynamic interactions between the
