Environmental Engineering Reference
In-Depth Information
air quality and thermal comfort. The main purpose is to reduce the energy
consumption in the commercial and public building sector and hence also
to reduce carbon dioxide emissions. One way to proceed is to carry out the
energy calculations in different steps for existing buildings.
1. The first step is to collect measured energy use information (e.g. from
energy bills) and make a benchmarking to decide if the actual build-
ing is better or worse compared to similar buildings—for example,
if the energy use seems to be higher than the average for a comparable
grouping of buildings.
2. A second step is to make a careful energy calculation that can be
compared to the measured energy use. This has to be carried out to
identify the types of measures that can be recommended.
3. Some important aspects that are necessary to take into consideration
when developing a common tool for energy declaration of buildings
will be addressed. Figure 6.1 demonstrates the energy flow chart
proposed in the European Energy Performance Directive [1,2].
Energy certification and ways of
expressing energy requirements
Primary energy and
CO
2
emissions
Conversion factors
Delivered energy
Heating system
characteristics
Cooling system
characteristics
Ventilation
system
Hot water
Lighting
Net energy
Automation
and controls
Building
Heat
transmission
Indoor and
outdoor climate
Internal gains
Air change
Solar gains
FIGURE 6.1
Energy flow chart in buildings. (From Khalil, E. E. (2005). Energy performance of buildings
directive in Egypt: A new direction,
HBRC Journal
, Vol. 1.)
