Civil Engineering Reference
In-Depth Information
that buildings with highly insulated envelopes are often more sensitive to misuse
by users when overheating can be a concern. The correct use of ventilation and
shading systems are then crucial if buildings are to behave as expected.
Building automation is becoming a fundamental element to deliver buildings
that live up to expectations and provide indoor comfort with an optimised use of
energy. A Building Management System (BMS) is a computer-based control sys-
tem installed in buildings that controls and monitors the building's mechanical and
electrical equipment, and it is most common in large buildings. As a core function
in most BMS systems, it controls heating and cooling, manages the systems that
distribute this air throughout the building and locally controls the mixture of heat-
ing and cooling to achieve the desired room temperature. A secondary function
sometimes is to monitor the level of human-generated CO
2
, mixing in outside air
with waste air to increase the amount of oxygen while also minimising heat/cool-
ing losses. A BMS can also have the crucial role of controlling solar shading sys-
tems in order to optimise heating and cooling loads.
Smart BMSs allow for significant energy savings both in new and existing
buildings and avoid over-use of energy (Vraa Nielsen et al.
2011
). Although until
now BMSs were common in large commercial buildings, smaller systems suita-
ble for households are available under the broad definition of “home automation”
systems.
Building automation systems have the advantage of making the idea of the
“smart building” practicable where a building can react to constantly changing
conditions and situations caused by environment and occupants. A BMS takes
over the regulating and controlling functions related both to provision of energy
inside the building and to the manipulation of the envelope. While this has the
potential to deliver considerable efficiency, it is necessary to underline that exten-
sive automation involves some risks, such as vulnerability to technical system or
component failures, higher building costs, our growing dependency on technical
systems and also on manufacture and maintenance firms (Herzog
2008
).
Moreover, research about adaptive comfort shows that users feel more com-
fortable, and are tolerant of larger temperature variations, if they can define
their own environment, for example opening a window (Brager and de Dear
cit.; Brager and de Dear
1998b
) or defining their luminous environment through
the control of shading devices (Galasiu and Veitch
2006
). This is already trans-
lating in buildings where the envelope, far from being sealed, can be opened to
activate natural ventilation when this is effective. Such hybrid buildings, that
can work both with mechanical systems and passive natural ventilation, should
become more common but pose additional challenges to BMS designers because
of the more complex heat exchange mechanisms and the potential misuse by the
occupants.
Smart-ECO buildings will require the right balance between automation and
grid integration with the flexibility and resilience provided by overall sound build-
ing design (good insulation, effective shading and thermal storage capacity, as
described in the relevant paragraphs of this topic). This brings us back again to the
fundamental role of the designers and of a well designed and planned building.
