—W H I T E PA P E R

Energy efficiency of smart buildings
Towards zero consumption andbeyond

ENERGY EFFICIENCY OF SMART BUILDINGS

2TO W A R D S Z E R O C O N S U M P T I O N A N D B E YO N D—
Ready forthe sustainability challenges ahead—
Making buildings smart
with smart solutions by ABB

The rate of urbanization is growing rapidly – 55% of the world's population lives
in urban areas nowadays, and the proportion is set to increase to 68% by 2050.1
This means that infrastructure will continue receiving massive development, andthe number of buildings will continue to increase substantially worldwide.

Building energy use is never uniform –the water consumption and need for air
conditioning depend on the occupancy,
the time of day and the weather. Modernbuildings must be flexible and adapt tochanges promptly.

Other
5%

Transport
28%
Otherindustry
31%

Constructionindustry
6%

Governments all over the world are legislating to reduce
the energy consumption and CO2 emissions from buildings,
and professional organisations are also establishing therelevant certification programs. For example, the U.S. Green
Building Council has developed the Leadership in Energy
and Environmental Design (LEED) certification scheme.
LEED certified buildings resulted in $1.2 billion in energy
savings between 2015 and 2018.⁵ In the European Union,
new regulations demand that all new buildings should havean energy consumption level close to zero. The Energy
Performance of Buildings Directive (2018/844/EU) aims
to decarbonize national building stocks by 2050.
When we aim to minimize energy consumption while still
optimizing the living conditions in buildings, we needto rethink the whole system from the ground up. Every
possible way to save energy must be considered, andthe most energy efficient technologies and techniquesmust be applied.

Buildings
30%
Other10%—Global energy consumption by sector, according to the IEA.²

Building automation and control solutions
Much of the savings in smart buildings come from theadjustability and controllability of the systems. Sensors allover the building continuously measure indoor and outdoor
ambient conditions and help the building management
system (BMS) controllers adjust the HVAC accordingly.
Movement detectors facilitate optimization of different
areas when they are not in use. Water circulation can be
optimized depending on the need as well, and tap water
pumps can be stopped during silent hours.
Real time information from occupancy sensors can tell when
an elevator is needed and how many stops it makes sense
to have before it reaches its destination. This can prevent
unnecessary stops when the elevator is already full or limit
elevator occupancy to avoid the spread of disease in special
situations like during a pandemic.

—ABB’s AC500 PLC open control platform
enables energy efficient management of
a whole building via connections to othersmart network solutions and protocols.

ABB’s set of building automation and control solutions
ensure advanced, energy-efficient and safe operation ofbuildings through powerful local or remote monitoring
across all levels, for the best occupant comfort and safety.

Elevators
3%

Space heating
25%

Office equipment
3%

Buildings are responsible for over 30% of global
energy consumption.² To improve our living conditions, we have engineered solutions to control thetemperature, humidity, and fresh air flow in buildings. Not surprisingly, heating, ventilation, and airconditioning (HVAC) consume on average about 50%of the energy used in buildings.³ At the same time,in large commercial buildings the equipment used
to move people, like escalators and elevators, canaccount for 2-5% of the building’s energy use.⁴
Therefore, improving the energy efficiency ofthese systems is essential.

The indoor temperature must follow changes in the outdoor
weather conditions. Seasonal variation in some areas may
be over 50°C, and the daily variation can be over 20°C. Dayor night, sunny or overcast – it all affects a building’s indoor
environment.

—
A typical power demand
profile for an officespace on weekdays.

Computing6%
Water heating
7%

Lighting
10%

Cooking
7%
Cooling9%Power demand

Because of the exponential growth of the global population,and especially the rising population density in urban areas,
the energy and water consumption of both new and existingbuildings should be optimized to increase energy efficiency
and reduce greenhouse gas (GHG) emissions.

3

Refrigeration
10%
Ventilation
10%

00:00

—
A breakdown of the average energy consumption in commercial buildings.⁶2:00

4:00

6:00

8:00

10:00

12:00 14:00
Time

16:00

18:00

20:00 22:00

24:00

ENERGY EFFICIENCY OF SMART BUILDINGS

Variable speed drives
Systems to control different processes inside buildings haveexisted for decades. However, the energy efficiency of thesesystems has not been sufficient. The development of variable speed drive (VSD) technology has enabled us to solve
many of the energy loss problems in buildings.
Because building systems like HVAC run at partial loads formost of the time, variable speed drives can save energy byan average of 20 to 60% compared to traditional damper
or valve control methods. Such massive energy savings are
possible because drives are able to adjust the motor speedof fans, pumps and compressors directly to meet the current building needs. Variable speed control delivers the full
benefit of running HVAC applications at partial load, allowing accurate control of ambient CO₂ levels, temperature,and humidity for the best occupant comfort, health andsafety, while optimizing the energy use.

TO W A R D S Z E R O C O N S U M P T I O N A N D B E YO N DDamper adjusting
VSD adjusting speedPower lossSpeed n1Pressure4Q2

Q1Flow—The graph shows how power consumption changes with decreasing theflow rate from Q1 to Q2 with a damper and a VSD. The damper doesn’t
decrease the speed of the application but rather creates the resistanceto decrease the flow, so the energy gets wasted (power loss square inthe graph). The VSD decreases the application speed as well (from n1to n2) making it consume less energy, so no energy gets wasted.

Outputpower 100

Input
power 14591%—The ACS880 regenerative
drive family brings specificbenefits to elevator operation.

Drives help to save a considerable amount of energy throughmotor speed control. However, they can also generate
electromagnetic noise due to the constant switchingof elements in their design. This noise is called harmonic
distortion and it negatively affects power systemefficiency, increasing the total current and generating
higher losses as a result. Therefore, variable speed
technology for building systems must be selected carefully.

—
Conventional ventilation system
System efficiency = 69%

Standard Motorefficiency

AFE technology offers specific benefits to elevator systemefficiency because it enables the braking energy to be
recovered when an elevator descends and slows, insteadof losing it as heat through braking resistors or mechanicalbrakes. Drives with a regenerative unit built-in can run
elevator motors as generators during braking and feed
the energy back to the network or an accumulator for lateruse, for example, to lift people when the elevator ascends
or in other building processes like HVAC.

—ABB’s ACH580-31 ultra-low
harmonic drives for HVAC
based on active front end
drive technology.

Speed n2

Usefulpower

To achieve the greatest energy savings, it is crucial toensure that drives are well integrated into the BMS for
smarter and more efficient building management. Supportfor all common building automation protocols, including
BACnet, as well as the wireless control capabilities in ABB
drives, enables complete and seamless integration.

Belt Drive
efficiency

98%

Fan
efficiency

78%

Damperefficiency

ABB’s active front end (AFE) drives limit current harmonics
to 3%. In contrast, the current from a conventional 6-pulse
drive technology with passive harmonic mitigation components has a harmonic content of about 40%. As a result,a system using a 6-pulse drive has 16% more current losses
than a system with no harmonics.

99%
2

—
Energy-efficient ventilation system
System efficiency = 83%—
Total line current Irms and relative
Joule losses as a function of
the THDi harmonic content.

1,8

1,64

1,6Input
power 121

Outputpower 100

1,41,36

1,2Variable Speed Drive
efficiency

98%

5Energy-efficient Motorefficiency

96%

More-efficient Fan
efficiency

88%

1,16

10%

20%

40%

60%

THDi, %Irms

Joule losses

80%

100%

120%

6ENERGY EFFICIENCY OF SMART BUILDINGSTO W A R D S Z E R O C O N S U M P T I O N A N D B E YO N D

7—ABB EC TitaniumTM integrated motor
drives combine the highest available
SynRM efficiency with a compact design.

—IE5 synchronous reluctance motors(SynRM) reduce energy losses by up
to 40% compared to IE3 induction
motors.

equipment like air handling units, while also ensuring higher
efficiency over the load profile compared to the more established commutated (EC) motor technology currently used in
the market.
Since HVAC applications run for most of the time underpartial load, SynRM motors offer excellent energy saving
potential.

EC TitaniumTM speed-load efficiency

100%

Synchronous reluctance technology combines the performance of permanent magnet motors with the simplicity
and service-friendliness of induction motors. The rotor ina synchronous reluctance motor has no magnets or windings and suffers virtually no power losses. It also requires
less material for manufacturing than a traditional motor– a great bonus for sustainability.

100%Load

Because buildings operate for most of the time at partial
loads, it’s important to consider a motor’s partial load
performance instead of just the nominal performance.
A SynRM IE5 motor at partial load offers even greater
advantages over other motor technologies.

Efficiency

More efficient motor technologies
Variable speed drives help save a lot of energy, but witha small investment savings can be increased further. The
optimal companion to a variable speed drive is a high efficiency motor like ABB’s IE5 synchronous reluctance motor(SynRM). Compared to an IE3 energy efficiency class induction motor, it offers up to 40% reduced energy losses,delivering ultra-premium energy efficiency – a new levelof efficiency defined by the International ElectrotechnicalCommission. This makes SynRMs the new first choice tomeet the growing global demand for improved energyefficiency.

Following the market need for rational building space
usage and increased HVAC equipment compactness, ABB
has developed a motor with integrated speed controls.
The EC TitaniumTM motor is highly efficient and has themotor drive built-in. It combines synchronous reluctanceand permanent magnet technologies for a sustainable,
wirelessly connected solution to improve the customer's
bottom line. EC TitaniumTM helps to save valuable space in0%

450

540

720

900

1080

1260

1440

Speed (RPM)

EC TitaniumTM—
ABB’s SynRM IE5 motors can achieve the highest
energy savings in buildings, even at partial loads.

StandardEC motor

Fan curve

1530

18000%—ABB EC TitaniumTM vsa conventional EC motor:
speed-load efficiency ofa 2.2 kW, 1800 rpm motor.

ENERGY EFFICIENCY OF SMART BUILDINGS

8Digital services
The world is going digital and the buildings segment isno exception. Applied to buildings, digital technology canincrease overall transparency and help optimize building
system performance for better occupant comfort andreduced energy use.
The ABB AbilityTM Digital Powertrain concept connects
drives, motors, pumps, and bearings through the ABB
AbilityTM cloud service, taking efficiency to new heights.
Condition monitoring services for powertrains deliver
real-time reports to facility managers on energy
consumption and the performance of equipment usedin the HVAC, water supply and other building systems.
This data provides deeper insight into building operations
and it can be used to identify which parts of a system
consume most of the energy so they can be optimized first.

TO W A R D S Z E R O C O N S U M P T I O N A N D B E YO N D

The digital powertrain concept helps make buildings moreenergy efficient and also more sustainable through smarter
maintenance. With continuous condition monitoring, there
is no need to run constant manual checkups – all the data
about building maintenance is collected in a cloud service
and is easily available, relieving the pressure on service
teams and reducing the number of service-related trips toa minimum. Spare parts can also be brought to the site byservice engineers on the first visit, saving traveling timeand eliminating related emissions.
With predictive maintenance it is possible to avoid failures
by foreseeing the status of equipment and proactively
keep components performing, rather than repairing orreplacing them with incident-based reactive maintenance.
It is one more step towards improving a building’s sustainability and reducing its carbon footprint.

Remote Assistance—Return on investment
and other benefits
Modern energy saving systems are often good investments.
For building operators and owners, a basic smart management system can generate annual savings of 25%, witha payback period of less than two years.⁷
A good example is a recent case with ABB HVAC drives andIE3 energy efficient motors used in the renovation of theHVAC and hot water supply systems of the InterContinental
hotel in Madrid. Thirteen ABB variable speed drives andsixteen IE3 motors were integrated into the BMS, which
resulted in energy savings of around 40%, helping the hotel
to meet its sustainability goals. Over a year these savings
totaled 445 000 kWh, cutting the hotel’s annual energy billby $37 000, which delivered on the projected return on
investment in exactly two years.

An energy-efficient building with smart management systems can be a tempting dealmaker on many levels for manydifferent target groups. In the commercial world, investors,developers, buyers and tenants are increasingly aware of
how an energy efficient building can boost the positive
reputation of their company. It has also been reported thatpeople who work and live in “green” buildings are happier,healthier, and more productive.7

Backup Management
Initial cost of an
IE3 motor anddrive package

Bearing

Alarm Management

Gateway

ABB AbilityTM
cloud

Offline DataCollection(1)		 United Nations, Department of Economic and Social Affairs, 2018.
(2)		 IEA, Energy Technology Perspectives, 2017.

Asset Health(3)		 US Energy Information Administration, Commercial Buildings Energy
Consumption Survey: Energy Usage Summary, 2016.
(4)		 American Council for an Energy-Efficient Economy,		 Advancing Elevator Energy Efficiency, 2015.

Pump(5)		 HSBC. Smart Buildings Cut Emissions. March 2020.

Condition-based
Maintenance—The ABB’s condition monitoring
services for powertrains – increased
efficiency and prolonged lifetime.

Savings gained fromusing an IE3 motorand drive package

Together with renewable energy sources like wind and solar
power, and energy regeneration technologies, it is possible
for buildings to generate surplus energy, which will create
extra revenue for the owners when the surplus energy is soldback to the grid.

DriveMotor9(6)		 Commercial Buildings Energy Consumption Survey, EIA 2016.
(7)		 U.S. Green Building Council, 2018.

2 yearperiod10

ENERGY EFFICIENCY OF SMART BUILDINGS© Copyright 2021 ABB. All rights reserved.
Specifications subject to change without notice.

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