An Efficiency Benchmark for the Building Industry
Introduction
Buildings account for over one third of global energy consumption and are responsible for
an equally significant amount of carbon dioxide (CO2) emissions. In the Indian context,
with rapid urbanization and growing energy demand, it is essential to make sure that the
upcoming building stock is built in the most efficient way. The fact that 70% of the India
of 2030 is yet to be built provides a great opportunity for the building industry fraternity
to transform the way buildings are designed and to adopt a sustainable approach. Though
renewable energy sources like solar photovoltaic (PV) are getting cheaper by the day and
are witnessing tremendous growth, it is important to understand that the first step to being
sustainable is to bring down the demand (energy, water, materials, etc.) through resource
efficiency measures, and the second step is to meet the demand through renewables,
recycling, etc.
While the building industry embarks on the path of efficiency, it helps to have a
building efficiency benchmark to guide design and operations. The benchmark should
be unreasonable and challenging, but at the same time practically achievable. One such
benchmark is the Infosys EC-53 building, which was inducted into the ACREX Hall of
Fame in 2017.
Building Features
The Infosys EC-53 building, located in Electronics
City, Bengaluru is a combination of innovation
and excellence in building design and operation.
Sustainability measures were an integral part of the
design right from the concept stage, and included
the building envelope, innovative cooling system,
energy metering, automation and continuous
performance monitoring. The salient features of the
building are described below.
Pushing the Envelope
Building envelope is the most important aspect
of an efficient building design and can impact up to
50% of cooling demand. While most critics would
vote against insulation in a moderate climate like
Bengaluru, the EC-53 building has a fully insulated
high performance envelope. This includes insulated
walls (U value: 0.4 W/m2K), insulated roof (U value:
0.3 W/m2 K) and high performance glass and
shading for windows. What this has resulted in is an exceptionally low cooling requirement of about 160 TR1 at
peak for a building area of about 15000 m2 (160,000 ft2). High
performance spectrally selective glass (light transmission of 42%,
solar factor of 0.22 and U value of 1.05 W/m2 K) and shading on
windows has ensured that there is ample natural light inside the
building and at the same time occupants feel comfortable without
glare or heat radiation from the windows
Selecting the Right Systems and Efficient Equipment
The second most important step for achieving a high
performance building is to select the most efficient system for the
building. LED lighting is used throughout the building to ensure
low energy consumption and low maintenance due to the long
life of LED lamps. All rest rooms are equipped with motion sensors
that ensure lights are kept off when there is no occupancy The EC-53 building was the first in India to implement a
radiant panel based cooling system. The radiant panels (supplied
by Uponor) are in the form of ceiling tiles and have small pipes
within them through which cold water at 16°C is circulated to take
care of the sensible load in the building. One floor of the building
uses radiant panels developed by the Infosys team to achieve cost
effectiveness and higher cooling efficiency. Air handling units take
care of the latent load in the building and are equipped with two
cooling coils – one with 16°C chilled water and the other with 7°C chilled water.
1TR = 3.517 kW
Other important features of the HVAC system include:
• All equipment with variable speed drives (chillers, pumps,
cooling towers, AHUs).
• Magnetic bearing chillers for high efficiency and low
maintenance.
• Automatic tube cleaning system to ensure chiller efficiency.
• Dual source units (DX + chilled water) for critical areas like
server rooms.
With all these interventions in HVAC, the annual average
efficiency of the chiller plant (chiller, pumps and cooling tower)
was measured to be 0.42 kW/TR
Performance Monitoring
An efficient design does not always translate into efficient
operation if the right metering and performance measurement
is not carried out. The EC-53 building is equipped with a Building
Management System (BMS) with accurate sensors that enable
efficient operation of building systems including proper scheduling
and control of different equipment remotely. The role of the BMS
does not end here. Smart algorithms defined in the BMS make sure
the systems ramp up or down based on the building requirement.
The efficiency of various equipment like chillers and pumps is
continuously tracked with respect to their design curves, and any
deviation is highlighted to enable the operations personnel take
appropriate action. Any critical parameter going out of range
triggers an alarm and notification to the operations personnel
so that any equipment failure can be foreseen and preventive
action taken. Effective use of BMS for control as well as continuous
performance monitoring of the building is a distinguishing feature
of the EC-53 building and several other buildings of Infosys
Solar Energy
The EC-53 building has an installed capacity of 90 kWp solar
PV plant on the rooftop. A unique feature of the plant is that it
consists of 5 different solar technologies of equal capacity on the
same roof. This makes for a very accurate comparison between
different technologies for the same weather parameters including
temperature, humidity, dust, etc. The technologies installed are
monocrystalline, polycrystalline, HIT, CIS thin film and Cd-Te
thin film. The plant is able to meet about 10% of the energy
requirement of the building on an annual basis
Water Wise
Water is a precious resource, the value of which is inadequately
understood by the society today. Water scarcity is a serious problem
that is increasing every day. When a significant population of the
country does not have access to clean water, it is all the more
imperative to use the available water most judiciously and harvest
every drop of rainwater.
The Infosys EC-53 building has a very low water demand of
25 litre per person per day in all (15 litre fresh water and 10 litre
recycled water), owing to low flow fixtures, dual flush toilets,
waterless urinals, etc. Hundred percent of the wastewater is
recycled in the Sewage Treatment Plant (STP), and the recycled
water is used for flushing, irrigation and cooling tower makeup
requirements. Rooftop rainwater is harvested in a dedicated
tank and used for potable purposes. Last year, about 42% of the
fresh water requirement in monsoon months was met through
rainwater.
Benchmarking Parameters
• Energy Performance index (EPI): 84 kWh/m2 per annum
(includes all the energy consumed in the building) for 100%
daytime occupancy and 50% night time occupancy.
• Building peak electrical load: 2.85 W/ft2 (peak observed at
building incomer in a year).
• Light Power Density (LPD): 0.5W/ft2.
• Peak cooling capacity: 1000 ft2 per TR.
• Chiller plant efficiency: 0.42 kW/TR (annual average).
• Solar PV plant capacity: 90 kWp (meets about 10% of annual
energy requirement).
• Water requirement: 25 litre per person per day.
Conclusion
All the above strategies are replicable for other buildings as
well. The cost of the building is not higher than a regular building.
At Infosys, we have consistently observed that efficient buildings
are less expensive than regular buildings when there is a focus
right from the initial design stage. It only requires a small additional
effort at the design stages and setting the expectations right for
the entire design team. It requires
questioning every assumption
and frugal engineering. It requires
rejecting thumb rules and adopting
a data driven approach. Most
importantly, it requires will from
the entire design team including
the owner to achieve a sustainable
high performance building.
Introduction
Buildings account for over one third of global energy consumption and are responsible for
an equally significant amount of carbon dioxide (CO2) emissions. In the Indian context,
with rapid urbanization and growing energy demand, it is essential to make sure that the
upcoming building stock is built in the most efficient way. The fact that 70% of the India
of 2030 is yet to be built provides a great opportunity for the building industry fraternity
to transform the way buildings are designed and to adopt a sustainable approach. Though
renewable energy sources like solar photovoltaic (PV) are getting cheaper by the day and
are witnessing tremendous growth, it is important to understand that the first step to being
sustainable is to bring down the demand (energy, water, materials, etc.) through resource
efficiency measures, and the second step is to meet the demand through renewables,
recycling, etc.
While the building industry embarks on the path of efficiency, it helps to have a
building efficiency benchmark to guide design and operations. The benchmark should
be unreasonable and challenging, but at the same time practically achievable. One such
benchmark is the Infosys EC-53 building, which was inducted into the ACREX Hall of
Fame in 2017.
Building Features
The Infosys EC-53 building, located in Electronics
City, Bengaluru is a combination of innovation
and excellence in building design and operation.
Sustainability measures were an integral part of the
design right from the concept stage, and included
the building envelope, innovative cooling system,
energy metering, automation and continuous
performance monitoring. The salient features of the
building are described below.
Pushing the Envelope
Building envelope is the most important aspect
of an efficient building design and can impact up to
50% of cooling demand. While most critics would
vote against insulation in a moderate climate like
Bengaluru, the EC-53 building has a fully insulated
high performance envelope. This includes insulated
walls (U value: 0.4 W/m2K), insulated roof (U value:
0.3 W/m2 K) and high performance glass and
shading for windows. What this has resulted in is an exceptionally low cooling requirement of about 160 TR1 at
peak for a building area of about 15000 m2 (160,000 ft2). High
performance spectrally selective glass (light transmission of 42%,
solar factor of 0.22 and U value of 1.05 W/m2 K) and shading on
windows has ensured that there is ample natural light inside the
building and at the same time occupants feel comfortable without
glare or heat radiation from the windows
Selecting the Right Systems and Efficient Equipment
The second most important step for achieving a high
performance building is to select the most efficient system for the
building. LED lighting is used throughout the building to ensure
low energy consumption and low maintenance due to the long
life of LED lamps. All rest rooms are equipped with motion sensors
that ensure lights are kept off when there is no occupancy The EC-53 building was the first in India to implement a
radiant panel based cooling system. The radiant panels (supplied
by Uponor) are in the form of ceiling tiles and have small pipes
within them through which cold water at 16°C is circulated to take
care of the sensible load in the building. One floor of the building
uses radiant panels developed by the Infosys team to achieve cost
effectiveness and higher cooling efficiency. Air handling units take
care of the latent load in the building and are equipped with two
cooling coils – one with 16°C chilled water and the other with 7°C chilled water.
1TR = 3.517 kW
Other important features of the HVAC system include:
• All equipment with variable speed drives (chillers, pumps,
cooling towers, AHUs).
• Magnetic bearing chillers for high efficiency and low
maintenance.
• Automatic tube cleaning system to ensure chiller efficiency.
• Dual source units (DX + chilled water) for critical areas like
server rooms.
With all these interventions in HVAC, the annual average
efficiency of the chiller plant (chiller, pumps and cooling tower)
was measured to be 0.42 kW/TR
Performance Monitoring
An efficient design does not always translate into efficient
operation if the right metering and performance measurement
is not carried out. The EC-53 building is equipped with a Building
Management System (BMS) with accurate sensors that enable
efficient operation of building systems including proper scheduling
and control of different equipment remotely. The role of the BMS
does not end here. Smart algorithms defined in the BMS make sure
the systems ramp up or down based on the building requirement.
The efficiency of various equipment like chillers and pumps is
continuously tracked with respect to their design curves, and any
deviation is highlighted to enable the operations personnel take
appropriate action. Any critical parameter going out of range
triggers an alarm and notification to the operations personnel
so that any equipment failure can be foreseen and preventive
action taken. Effective use of BMS for control as well as continuous
performance monitoring of the building is a distinguishing feature
of the EC-53 building and several other buildings of Infosys
Solar Energy
The EC-53 building has an installed capacity of 90 kWp solar
PV plant on the rooftop. A unique feature of the plant is that it
consists of 5 different solar technologies of equal capacity on the
same roof. This makes for a very accurate comparison between
different technologies for the same weather parameters including
temperature, humidity, dust, etc. The technologies installed are
monocrystalline, polycrystalline, HIT, CIS thin film and Cd-Te
thin film. The plant is able to meet about 10% of the energy
requirement of the building on an annual basis
Water Wise
Water is a precious resource, the value of which is inadequately
understood by the society today. Water scarcity is a serious problem
that is increasing every day. When a significant population of the
country does not have access to clean water, it is all the more
imperative to use the available water most judiciously and harvest
every drop of rainwater.
The Infosys EC-53 building has a very low water demand of
25 litre per person per day in all (15 litre fresh water and 10 litre
recycled water), owing to low flow fixtures, dual flush toilets,
waterless urinals, etc. Hundred percent of the wastewater is
recycled in the Sewage Treatment Plant (STP), and the recycled
water is used for flushing, irrigation and cooling tower makeup
requirements. Rooftop rainwater is harvested in a dedicated
tank and used for potable purposes. Last year, about 42% of the
fresh water requirement in monsoon months was met through
rainwater.
Benchmarking Parameters
• Energy Performance index (EPI): 84 kWh/m2 per annum
(includes all the energy consumed in the building) for 100%
daytime occupancy and 50% night time occupancy.
• Building peak electrical load: 2.85 W/ft2 (peak observed at
building incomer in a year).
• Light Power Density (LPD): 0.5W/ft2.
• Peak cooling capacity: 1000 ft2 per TR.
• Chiller plant efficiency: 0.42 kW/TR (annual average).
• Solar PV plant capacity: 90 kWp (meets about 10% of annual
energy requirement).
• Water requirement: 25 litre per person per day.
Conclusion
All the above strategies are replicable for other buildings as
well. The cost of the building is not higher than a regular building.
At Infosys, we have consistently observed that efficient buildings
are less expensive than regular buildings when there is a focus
right from the initial design stage. It only requires a small additional
effort at the design stages and setting the expectations right for
the entire design team. It requires
questioning every assumption
and frugal engineering. It requires
rejecting thumb rules and adopting
a data driven approach. Most
importantly, it requires will from
the entire design team including
the owner to achieve a sustainable
high performance building.
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