Active energy efficiency in the built environment2
Active Energy Efficiency in
the Built Environment
”A new blend to the energy efficiency concept”
What is active energy efficiency?
Active Energy Efficiency is defined as effecting permanent
change through measurement, monitoring, and control of
Passive Energy Efficiency is regarded as the installation of
countermeasures against thermal losses, the use of low
consumption equipment etc.
It is vital, but insufficient, to make use of energy-saving
equipment and devices such as low-energy lighting.
Without proper control, these measures often merely
militate against energy losses rather than make a real
reduction in energy consumed and in the way it is used.
What should we do?
Everything that consumes power – from direct electricity
consumption through lighting, heating, and most significantly
electric motors, but also in HVAC control, boiler control, and
so forth – must be addressed actively if sustained gains are
to be made. This includes changing the culture and mindsets
of groups of individuals, resulting in behavioural shifts at work
and at home.
But clearly ‘this need is reduced by greater use of
Nowadays, energy efficiency is high on the agenda of most people. However,
understanding of what energy efficiency really involves and how energy
saving initiatives can be implemented remains fragmented.
Energy measures revolve around the consideration of thermal issues in the
building fabric with remedies such as insulation, glazing, and heat loss
countermeasures. For others, it is lighting, albeit often constrained to
merely installing low consumption systems. Those with significant heating
requirements may call for efficient boiler systems as the answer.
These are really only passive countermeasures that largely mitigate energy
loss rather than the energy deployed.
Active Energy Efficiency can be achieved when energy-saving devices are not only installed, but
controlled to use only the energy required. It is this aspect of control that is critical to achieving the
For example, consider an energy-efficient lamp that is left turned on in an empty room. All that is achieved is that less
energy is wasted than would have been using an ordinary lamp!
Reasons to consider Active energy
It is the management of energy use through measurement,
monitoring, and control that effects permanent change.
Moreover, compared with the costs (and technical skills
necessary to avoid risks) of installing thermal solutions,
energy control can be implemented at a relatively
modest price and with a very rapid payback. This is
especially true when measured against escalating
energy prices – most energy control solutions can
give returns within a few years.
Another very important factor that should drive Active
Energy Efficiency from this point forward is the need to
meet ambitious carbon reduction targets set by those
governments in alliance with the Kyoto Protocol. In the
built environment, for example, it is a fact that unless
existing buildings (as well as all new build) are made
energy efficient, it will simply be impossible to reach
the targets set for 2020.
Reducing greenhouse gas emissions was a global target set at the Kyoto Earth Summit in
1997 that was finally ratified by 169 countries in December 2006.
Under the Kyoto Protocol, industrialized countries have agreed to reduce their
collective emissions of greenhouse gases by 5,2% by 2012 compared to the year 1990.
Compared to the emissions levels expected by 2012 prior to the Protocol, this limitation
represents a 29% cut.
As architects we should resort approaches to
Efficiency that can be applied within new and
existing buildings –
in commerce, industry, private, public, and
residential – as well as
in manufacturing, industry, and the
In coming years, India is going to introduce this
trend among architects,
Current Scenario on active energy efficiency
Economies are readily possible in electricity generation and distribution, in its use and in
the way electricity can be used wisely to make efficiencies in the use of other energy.
The technology is there to control buildings’ energy use in lighting, HVAC, building
controls, and distribution. Lighting alone can account for 40% of a typical commercial
enterprise’s electricity consumption.
In industry there are proven systems to reduce the power consumed by electric motor
systems and to better control the application of electrical power throughout a plant. Two
thirds of electrical energy used by industry is used powering motors. In most countries
less than 10% of those motors have any kind of control and therefore cannot be slowed
down or switched off automatically
In the home, new products enable lighting and heating controls that enhance living
standards while saving electricity. In most countries, every single domestic dwelling
(including individual apartments) contributes about 6,5 tonnes of CO2 each year — or, to
put it another way, enough gas to fill six hot-air balloons! Yet, just switching off lights in
unoccupied rooms could save 2,2 tonnes per household. Computers, multiple televisions
sets, modern electrical appliances, air conditioning, and even outside lighting and
powered equipment have seen an exponential growth in consumption. Indeed, in many
western economies, domestic electricity consumption outstrips even industrial use.
In short, there is no reason not to be able to actively save electricity and other energy,
provided there is the understanding of what is at stake, and a desire to do something
Active energy efficiency
solutions for different building
While comfort and safety are probably the most important
selection criteria in homes, energy efficiency and the ability to
reduce the "environmental footprint" of the house are becoming
Average breakdown of home energy consumption :
Heating & Cooling: 60%
Electrical appliances: 14%
Hot water sanitary: 12%
Energy savings can be achieved through automating different
functions of everyday life:
Lighting control : turning off unnecessary lights, sensing when
nobody is in a room through presence detector, dimming light
intensity according to outdoor lighting conditions,
scheduling outdoor lighting according to predefined patterns, ...
Heating, Ventilation and Air Conditioning control: setting optimal
temperatures for the different rooms of the house, Predefining
heating/AC patterns in advance according to regular needs,
remotely controlling heating/AC, ...
Other features can also improve energy efficiency:
Solutions or architectures used in the application
Home automation solutions are focused on the specific automation requirements of private homes and on the comfort and security of its
residents. Usually, there are three main system architectures classified according to where the intelligence of the system resides:
1.Centralised Architecture : a centralised controller receives information from multiple sensors and, once processed, generates the
opportune orders for the actuators.
2.Distributed Architecture : all the intelligence of the system is distributed by all the modules that are sensors or actuators. Usually it is
typical of bus wiring systems.
3.Mixed Architecture : systems with decentralised architecture in that they have several small devices able to acquire and to process the
information from multiple sensors and to transmit this information to the rest of the devices distributed by the house.
Residential buildings are rarely, if ever, appropriate for precise metering and
measurement. However, there are still steps that can be taken towards adopting
Active Energy Efficiency practices.
The instinct to turn off equipment that is on stand-by (the LEDs in equipment such
as TVs, DVD players, hi-fi, home PCs, etc., consume huge amounts of electricity
collectively) will take
time to instil. In the meantime, there are technological aids that can effect big
One possibility is to install inexpensive
lighting controls. These range from the most sophisticated home automation to
simple room occupancy sensors. Families with teenage children know that it’s not
uncommon to have almost
every light in the home switched on even when just a single room is occupied!
In multiple occupancy dwellings such as apartment buildings,
there is scope for Active Energy Efficiency to be applied in
communal areas with occupancy controls for lighting, heating,
and ventilation. With a growth in mixed-occupancy building
where apartments, for example, are constructed above
commercial premises, the benefits of metering can also
be applied. Again, judicious lighting and heating controls
Various Equipment used for Active
Room control for lighting and heating
Cost efficiency and flexibility are particular important for private and commercial
Operational and maintenance costs can be significantly reduced thanks to the
optimum combination of different control functions: presence, brightness, time-
dependency for lighting, and temperature settings for heating and air-conditioning.
Automatic interaction of sensors and actuators avoids relying on uncertain human
action and secures savings while providing increased comfort and safety. This enables
substantial energy savings of up to 40% for lighting energy by automatically
extinguishing unnecessary loads.
Flexibility is really improved compared to traditional installations, as adaptations of
the building functions layout can easily be effected after reorganisations or moves.
Different trades like lighting, heating, blinds, air-conditioning, state and consumption
monitoring are connected and form an intelligent system.
The inhabitant is enabled to configure user-relevant setpoints at multi-functional
pushbuttons or graphical user-interfaces to the desired comfort and saving potential.
For example, functions can be recalled in one scenario, which previously were
controlled separately: blinds are lowered, lighting is adjusted and the room is heated
to just the right temperature.
Solution in brief
The displayed solution architecture provides the following exemplary technical
Lighting control - starts/stops el. lighting dependent on people presence and current
Heating control - adjusts the requested temperature and sets the heating into
standby mode whenever the room is unoccupied or a window is opened.
Main Energy Efficiency characteristics
● Installation effort/costs are reduced compared to conventional installations with
● Consumption of energy is reduced.
● Safety of persons and material assets is increased.
● Decentral and central switching and indicating is possible.
● Information-interchange between different crafts reduces the installation and fire
● Automated alarms or emergency calls are communicated.
● Remote monitoring or control can be effected.
● Technical extensions or changes are realised easily.
Automate lighting, temperature and shutter
control in office building
The facility managers want to realise substantial energy savings by controlling all the
parameters of lighting, heating and shutters. This enables substantial energy savings of up
to 35% for lighting energy by automatically extinguishing unnecessary loads
They want also to be able to extend easily the system at any time without laying new
Solution in brief
Cost efficiency and flexibility are particular important for private and commercial buildings.
All devices will be connected via a single bus line. When you activate a sensor (a push
button for example), an actuator will carry out all the switching commands required.
Operational and maintenance costs can be significantly reduced thanks to the optimum
combination of different control functions: movement detection, time-dependency for
lighting, and temperature settings for heating.
Automatic interaction of sensors and actuators avoids relying on uncertain human action and
secures savings while providing increased comfort and safety.
The displayed solution architecture provides the following exemplary technical functions:
Automatic lighting control: movement detectors can be used to control lights and roller
blinds according to movement detection in corridors, staircases.
Heating control: heat is supplied automatically at the exact time required and individually
via controllable room temperature control units. No need to turn the radiators up and down
manually. Don't worry: if you forget to do it, the KNX system will remember to do it for you.
Optimize working conditions in an office
Increase savings by reducing energy consumption
Increase employees comfort
Solution in brief
Install a centralized BMS in order to control lighting, heating, and cooling
The BMS will take in account people presence and absences, natural light level, opening and
closing times for the building
It will allow some derogations for temperature and lighting
Management of the space by defined zones
Greater flexibility for future office reconfigurations
Possibility to use DALI ballasts
Main Energy Efficiency characteristics
Installation effort/costs are reduces compared to conventional installations with same
Consumption of energy will be reduces
Safety of persons and material assests will be increased
Decentral and central switching + indicating in possible
Information-interchange between different crafts reduces the installation and fire load
Remote monitoring or control can be effected
Technical extensions or changes can be realised easily
Variable speed drive up to 630 kW for Pump and
Fan applications in Industry and Infrastructures
72 % of consumed electricity is used to turn on motors. 63 % of this energy is used for
fluid applications like pumps and fans. AC drives allow you to reduce energy
consumption by 50% on fans compared to conventional solutions (flow variation with
mechanical devices) and 20% to 30% on pumps according to their characteristics.
Fan example: at 80% of nominal flow, the energy consumption is 95% of nominal power
with conventional installations instead of 50% with AC drives.
Even thought flow variation is not needed, most of the applications are oversized
(pessimistic estimation of hydraulic loses). Optimising the pressure, AC drives save 20%
of energy compared to conventional solutions.
Using ECO8 software, you can easily estimate the energy saving according to your pump
or fan applications and duty cycle.
Main Energy Efficiency characteristics
Open to the main networks.
Industry: Ethernet, FIPIO, Modus Plus, Device Net, Interbus-S, Unitelway.
Building: LonWorks, BACnet, METASYS N2 and Apogee FLN.
High performance variable torque applications:
Fan: safety with forced start (fault inhibition, selection of the running direction
and reference speed).
Multipump: with the programmable multipump card, Altivar 61 brings you
flexibility, useability and adaptability in management of multiple pumps.
Pumps: essential functions to protect your installation under load, including
detection of overload and fluid absence.
IP54 version and "Simply Start" menu
Programmable time switch - IHP
IHP programmable time switches are used to program automatic operation of heating,
lighting, ventilation... in an accurate manner.
They control opening and closing of independent circuits according to a program set
by the user by memorization of On and Off switching operations
With 4 keys, a large screen and text-guided intuitive programming, they are easy to
program and to use
With the external input, they can be controlled with a switch or push-button away
from the electrical distribution panel board
With the memory key, saving and duplication of programs can be done easily
With the programming kit, more complex programs can be created with a PC and then
downloaded to the products
With the electrical distribution comb-busbar mechanical compatibility and the screw-
less connection, the installation becomes simple, faster and more reliable
Reduction of electrical energy consumption (the installation only operates when
necessary, operation during the post favourable rate periods)
Increased user comfort (customisation of operating periods, triggering accuracy)
Enhanced user safety by using the random operating mode proposed by the '+' versions
to simulate presence
They are adapted to all application types (bell, lighting, heating, ventilation, access
control...) irrespective of the sector of activity (residential, tertiary, public building,
agriculture, industry, etc.)
Active Front End (AFE)
The Active Front End is an option for frequency inverters to return energy to the line supply. It provides 4-
quadrant operation and thus is ideal for all applications with a generator operating mode. State-of-the-art
components, a new control concept, as well as a top-quality filter module all serve to reduce the total current
distortion factor THD(i) to a value of less than 4%.
THD(i) of less than 4%
Power factor of cos Phi 1 independent of the load and the energy direction
No converter transformer required
Line voltage drops of up to 40% without disturbing operation
Integrated radio frequency interference filter Wide frequency range
Adjustable regenerating power e.g. for operation with diesel generators
Line short-circuit power up to 100kA
Simple planning and installation
Line contactor already integrated
No external control voltage supply necessary
Integrated charging circuit providing a maximum fourfold power at the DC bus
Operation independent of the phase sequence
Optimised management of spare parts due to common components in the active infeed converter and the inverter
Energy regeneration to the line supply
Improved efficiency thanks to an innovative control system
No need for damping resistors (which cause heavy losses), thus making it is especially robust in heavily distorted supply
Reduction of transformer losses, wiring and switching devices
The Active Front End is connected upstream of the standard frequency inverter and consists of three components :
Active infeed converter
Line filter module (EMC filter, line contactor and charging circuit)
Line filter choke (3 parts)
Crane applications (hoists, long travel motion)
Downhill conveyors, winches, escalators
Complex drive systems
Test benches and high dynamic drives
Commercial lighting control
With Conventional electrical installations, you have to determine in advance how
and where your buildings switching system will be installed, before construction
But with KNX from Merten, you can keep options open. That’s because everything
in the system can be changed or extended at any time without the usual mess
and without laying new cables.
In addition, all building technology devices and installations are connected via a
single bus line.
The bus line is laid in parallel to the 230 vac power supply. When you activate a
sensor for eg a push button, an actuator will carry out all the switching
KNX is the only worldwide approved INTERNATIONAL STANDARD for home- and
building control. Its recent approval as an international standard (ISO/IEC 14543-
3) now confirms the global importance of the KNX standard.
In Building Automation System, there are many factors to be taken into account
like Flexibility, Comfort, Cost efficiency, safety and security. In terms of
comfort, take the following example: getting cosy in the evening no longer
means going from one switch or thermostat to the next. Instead, simply press a
single button to activate all the desired functions in one go., blinds are lowered,
atmosphere lighting is switched on and the room is heated to just the right
temperature. Scenes such as these can be created exactly as you want them and
you can do so via remote control, PDA, Touchscreen or PC.
Automatic Lighiting control:
Time dependent,automatic switching off of light sources during work breaks or on
Daylight dependent adaption of the lighting for optimum working conditions through light
control. With intelligent heating/cooling controls,energy costs can be reduced by up to
Automatiic lighting of corridors, staircase bu using motion sensors.
Individual heating/cooling control.
Presence dependent room heating/cooling.
Immediate closure of heating/cooling valve when window is opened.
cooling is supplied automatically at the exact time required and individually via
controllable room temperature control units.
Intelligent Blind Control:
Automatic control of the sun awnings via light sensors in accordance with the current
Automatic blind retraction via wind sensors during strong wind.
Automatic adjustment of the blind slats in accordance with the current sunlight intensity.
Flexible building management:
Flexible adaption of the building functions when rooms are used for different purposes eg
after reorganistion or a move.
Worldwide access to the entire building technology system via PDA, PC or Touch screen.
Monitoring of windows and doors or underground car parks by sensors that signal
Display of loads, performance curves and temperatures, immediate notification in the case
of critical temperature overshoots and automatic shutdown of devices at risk.
Display of fault signals and automatic forwarding of these signals to the responsible
electrician or the building manager.
Costly peak load avoided since loads can be switched on and off in a systematic fashion.
Begin with measurement (you don’t change what
you don’t know, you don’t know what you don’t
“Use the ‘only necessary’ energy and only when
‘necessary’ thanks to automation & control”-Motto
of active energy efficiency.
We can make permanent improvements to
processes, maintaining consistent performance
through monitoring and maintenance services.
Many measures are easy to install, with a low
implementation cost and a quick payback —
specifically when retrofitting existing building or
Active Energy Efficiency can be implemented in all
sectors (residential building, commercial building,
Active Energy Efficiency is vital in addition to
Passive Energy Efficiency measures in order to reach
the CO2 emissions reduction targets.
Robust Automation, Control, and Monitoring of
Energy Usage can deliver up to 30% Energy Savings