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The
high technology concept of intelligent buildings was introduced in the
United States in the early 1980s. Intelligent buildings use electronics
extensively and are high technology related.
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THE
ELECTRONIC VIEW
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The
electronic view of things may be addressed as four groups:
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Energy
Efficiency
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This
deals with the reduction of energy use to the bare minimum. Some
strategies used to reduce energy consumption in intelligent buildings are
Electric demand limiting, Adaptive control, Chiller optimization, Boiler
optimization and Optimal energy sourcing.
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Life-Safety
Systems
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This
consists of the use of high technology to maximize the performance of fire
alarm and security systems while at the same time minimizing costs. Life
– safety factors involved in intelligent buildings are: Reduced manpower
dependence, Closed-circuit television, Card access control, Smoke
detection Intrusion alarms and Emergency control of elevators, HVAC
systems, doors etc.
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Telecommunications
Systems
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Telecommunications
in an intelligent building consists of offering to tenants sophisticated
telecom features at a considerably reduced cost. Some of telecom features
involved in intelligent buildings are: PBX telephone system, Cablevision,
Videotext and Electronic mall.
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Workplace
Automation
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This
consists of the use of high-tech office automation systems to render the
operation of a company more efficient. Some of the factors involved in
workplace automation in intelligent buildings are Centralized Data
Processing, Computer Aided Design and Information Services.
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CONTROL
SYSTEMS
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Control
of devices in buildings offers a major challenge as far as maintaining
human comfort and energy conservation are concerned and requires a variety
of control systems to be employed. Hence use of intelligence-based systems
such as fuzzy logic controls is becoming popular. Other intelligence-based
controls are inductive learning, neural network and genetic algorithms.
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There
are different active and passive devices in buildings that make the
internal environment of a building comfortable. To achieve this intended
comfort some kind of control on these devices is required. These control
adjustments can be seasonal, daily or even more frequent depending upon
the device under control, the required parameter and the change in climate
conditions. Energy saving potentials have made the use of automatic
controls more common in modern buildings.
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One
of the oldest and simplest means for controlling a device is an on/off
switch, for example a thermostat. Thermostat offers closed-loop control of
a goal of Heating Ventilation Air - Conditioning (HVAC) system design in a
building is to provide comfort to the occupants. Because heating and
cooling loads vary with time of the day and of the year, an HVAC system
must be complemented with a good control scheme to maintain comfort under
any load conditions.
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Currently,
most commercial and institutional buildings are equipped with proportional
– Integral- Derivative (PID) controllers that are tuned manually or with
auto tuners. Fuzzy logic based building automation research is also being
conducted in IIT Delhi.
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Wireless
networking
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Control
of existing electrical, mechanical systems in buildings is a very complex
task often limited to manual control. Though new and sophisticated
controls are being implemented in modern buildings, control of these
systems pose two major challenges, namely (i) cost of retrofitting the new
controls in existing buildings and (ii) adding together the heterogeneous
components. The cost and cumbersome laying out of wiring limits the number
of sensors and controllers that can be placed in a building. Hence
wireless devices are emerging as a cost effective solution. Wireless
sensors reduce the need of complex wiring when a large number of devices
are used in big buildings.
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In
future, most of the devices in buildings will be intelligent and will have
the ability to communicate with each other and various control systems.
Intelligence as applicable to a device can be due to its ability to
recognize its available resources, to use other devices’ resources and
to report the failures. There can be wireless sensors for measuring
various parameters like temperature, wind velocity, light level,
occupancy, humidity etc., in fact a radio can be attached to any sensor to
transmit wireless data. Also the actuators like venetian blind controller,
light dimmers, heating controller can get signals from wireless sensors
and controllers.
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The
latest technology makes it possible to change the indoor environment to
adapt to the user’s requirements as soon as the user enters a
conditioned space. User can carry a small transmitter that can relay the
user’s ID and his preferences for indoor climate.
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Security
issues are vital in wireless devices. As information is not traveling over
wires and can be tapped easily in air, which is a shared medium, security
becomes a very important factor. It may be possible for an intruder to tap
the data of a wireless occupancy sensor and find out the time when the
room is unoccupied. Intruder can also create false alarms by forging a
sensor’s data and disrupt normal functioning. Major issues related to
security like integrity, authenticity, availability and confidentiality
have to be dealt with before such technologies are put in market.
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Ethernet
for building automation
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Ethernet
has emerged as the standard system level network due to its universal
acceptance. Building Ethernet TCP/IP protocol capability right into the
controller devices provides Ethernet connectivity without the need for
gateways, terminal services, or other miscellaneous hardware. The
advantage of this capability is that it allows use of existing corporate
network as the main system backbone.
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The
benefits of wide area networks are achieved by putting the building
control system up on the Ethernet network. Facility mangers can use this
facility to easily transfer their building data over a remote network and
send critical building alarms via-e-mails and pagers. Further the facility
manager by using a web browser and continuum built-in wed server
capabilities in the system can retrieve real time data from anywhere in
the system, make changes to temperature, humidity set points, monitor
equipment run times and energy consumption and other activities right from
his desktop PC.
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FUTURE
TRENDS IN RESEARCH
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With
the present trend of research continuing it is expected that field of
intelligent buildings will get stabilized in about 3 decades. Days are not
far away that the intelligent building systems will automatically operate
and maintain buildings by. Automatically sensing installed equipment;
Check for proper installation. Generating control algorithms; Implementing
optimal, adaptive control, Diagnosing and correcting operating episodes
that produce inefficient or uncomfortable conditions, Managing maintenance
and providing performance data in usable forms for building operators,
facility managers, and owners, both local and remote.
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