c ase
Stu dy Spectral
Serv i c es
C o n s u lta n ts
C o r p o r ate
O f f ice
The following article was published in High Performing Buildings, Fall 2008. ©Copyright 2008 American Society of Heating, Refrigerating and
Air-Conditioning Engineers, Inc. It is presented for educational purposes only. This article may not be copied and/or distributed electronically
or in paper form without permission of ASHRAE.
Daylight With Less Heat
I
B y P r e m C . J a i n , P h . D . , F e l l o w / L i f e M e m b e r A SHR A E ;
a n d A s h i s h Ra k h e ja , M e m b e r A SHR A E
ndia is one of the
B u i l d i n g At a G l a n c e
Building Name Spectral Services
Consultants Pvt. Ltd. Corporate Office
Location Noida, India
Size 16,000 ft2
Started 2006
Completed 2007
Use Corporate office for 150 staff members
Cost $1.1 million
Distinctions LEED-NC Platinum
world’s top 10 energy
Building Team
consumers, and
Owner Spectral Services Consultants Pvt. Ltd.
growth is expected around
Architect ABRD Architects
6% annually over the next
Fundamental and Enhanced
Commissioning Agent Godrej & Boyce Mfg. Co. Ltd.
few years. However, Indian
Construction Manager Consortium Consultancy
Energy Consultant Environmental Design Solutions
companies are working to
LEED Facilitation CII – Godrej Sohrabji Green Business Centre
cut energy consumption. The
MEP Consultant Spectral Services Consultants Pvt. Ltd.
Spectral Services Consultants
Interior Designer Payal Jain Inc.
Civil Contractor Ahluwalia Contracts (India) Ltd.
Corporate Office in Noida,
HVAC Contractor Suvidha Engineers India Ltd.
India, achieves over 36%
Electrical Contractor Ahluwalia Contracts (India) Ltd.
Building Management System
Contractor iMetrex Technologies Ltd.
energy savings mainly by pro-
Public Health Engineering Contractor D S Gupta Construction Pvt. Ltd.
viding daylight to occupants
throughout the day without
gaining heat from the sun.
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B u i l d i n g s F a l l 2 0 0 8
F a l l 2 0 0 8 H i g h
Performing
Buildings
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The payback period is expected to be
less than four years.
Building Envelope
To accomplish the daylighting strategy,
the building faces north-south, the
optimal orientation for a building on
the Indian subcontinent. Heavy glazing on the north and south façades
brings natural light into the space. In
addition, recessed windows with fins
for shade cut down on direct solar
heat gain on the west façade, which
receives the most direct sunlight.
The wall to window ratio, optimized at 22.5%, maintains a balance
between heat ingress and daylight
harnessing. Windows are hermetically
sealed low-e double glass with a 0.33
shading coefficient and 60% visible
light transmissivity. External walls are
made of 8 in. thick autoclaved aerated
concrete blocks, backed by 25 mm
closed cell rubber insulation. This
results in a U-value of 0.077 Btu/
h·ft2·°F. Roof surfaces are provided
with 3 in. thick extruded polystyrene,
covered partly with glazed white tiles
and high solar reflectance paint (78
Noida, India
The fresh air quantity is 30% higher than recommended by Standard 62.1-2004.
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B u i l d i n g s F a l l 2 0 0 8
Noida is located towards the north of
India and close to Delhi. The climate in
the area has an average temperature of
110oF in the summer, 95oF during monsoon season and 45oF in the winter. In a
year, 90% of days are bright and sunny.
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solar reflectance index). The resulting
U-value is 0.063 Btu/h·ft2·°F.
Harnessing Sunlight
Despite the hot and humid climate,
the 16,000 ft2, five-floor office building provides daylight at a 250 – 350
lux level throughout the day without
gaining heat from the sun. More
than 75% of the building’s interior
is daylit, and 90% of occupants
enjoy outside views. The building
site and most parts of northern India
receive more than 300 days of bright
sunshine annually. On most working days, the sun provides sufficient
light so that electric lighting is
switched off during operation hours.
A large atrium extends over all
floors of the building. A south-
inclined (15 degrees to horizontal)
skylight encompasses the entire
atrium. Because the sun moves
southward for the majority of the day,
the skylight, also called the light
catcher, plays an important role in
daylight harnessing. To minimize
heat from direct sunlight, the light
catcher has permanently inclined
louvers of dull aluminum metal.
By blocking direct sunlight throughout the day, the louvers reduce airconditioning loads and glare on
workstation computers. The louvers’
angle was computer simulated to
study year-round performance.
Night Lighting
In the evening, an advanced lighting management system automati-
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Recessed windows with fins cut down
on direct solar heat gain.
Da y l i g h t P e r f o r m a n c e
diverted to authorized disposal
agencies. To reuse resources, furniture from Spectral’s old offices was
remodeled and used in the building.
A small amount of Forest Steward
Council certified wood was used for
the executive floor furniture. Lastly,
2.5% of the building material, like
bamboo flooring, is from rapidly
renewable resources, and 7.7% is
reused or salvaged material.
A model was used to estimate daylight
performance. The illumination for the
space was calculated using the clear
sky conditions at noon on the equinox
(March 21).
indoor temperature and relative
humidity between 23°C and 25°C
and 40% to 60% respectively. In
addition, all air-handling units can
execute a complete air-side economizer cycle for free cooling of the
indoors during fair weather.
A south-inclined skylight encompasses the entire atrium and harnesses daylight.
Fire Safety
Even though the constructed area of
the building is small, it provides a
fire-safe environment to occupants.
An intelligent, addressable fire alarm
system and water-based fire fighting
system ensure a high level of fire
safety, exceeding the norms of India’s
national building code.
Reusing Materials
cally switches on internal lighting.
The system ensures a constant lux
level using dimmable ballasts on
each lighting fixture. Occupancy
sensors control lighting in regularly
unoccupied areas like toilets and
meeting rooms. The average internal lighting power density is 0.63
W/ft2, approximately half the IESNA
recommended lighting power density of 1 W/ft2 for offices.
Indoor Air Quality
A high level of indoor air quality is
maintained by monitoring indoor CO2
levels and controlling the fresh air
quantity injected into the space by
modulating fresh air dampers. The
fresh air quantity is 30% higher than
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recommended by ANSI/ASHRAE
Standard 62.1-2004, Ventilation
for Acceptable Indoor Air Quality.
Recovering energy from the bathroom
and atrium exhausts precools the
fresh air. Electrostatic precipitators
with MERV 13 efficiency combined
with prefilters with MERV 6 efficiency
on all air-handling units ensure a
dust-free indoor environment.
The air-conditioning system,
besides providing a dust-free
environment to occupants, closely
controls indoor temperature and
relative humidity levels. Each airhandling unit in the building is
provided with an ultrasonic humidifier and electrical heater installed
within the supply air duct. The
B u i l d i n g s F a l l 2 0 0 8
During construction, 96.6% of the
building waste was collected and
Below Permanently inclined louvers
block direct sunlight and reduce
air-conditioning loads.
More than 75% of the building’s interior is daylit.
building’s management system runs
the entire operation, maintaining
F a l l 2 0 0 8 H i g h
Energy Use
With energy-efficient features, such as
north-south building orientation, insulated
envelope, low-e double glass and reduced
lighting needs, the peak air-conditioning
load for the building is 50 tons of refrigeration. This is approximately half the load
of a similar office in New Delhi, India. The
average year-round load for the Spectral
Office hovers around 35 – 40 tons of refrigeration. The installed air-conditioning plant
consists of 72 tons of refrigeration, high
COP water-cooled screw chilling machine
with twin compressors, variable speed
chilled water pumping system, cooling
tower with variable frequency drive, air-handling units on all floors coupled to variable
frequency drive, and internal air distribution through variable air volume boxes.
The baseline yearly electrical
energy demand for the building, per
ANSI/ASHRAE/IESNA Standard 90.12004, Energy Standard for Buildings
Except Low-Rise Residential Buildings, is
394,196 kWh (25 kWh/ft2 per year) and
the predicted actual annual energy demand
for the building is 242,086 kWh (15 kWh/
ft2 per year). The building achieves 38.6%
electrical energy savings over the Standard
90.1 base building. Actual performance is
even better, as seen in the energy table.
The average monthly energy bill is $2,500.
This is less than half of the bill at Spectral’s
previous offices, which were well-designed
conventional buildings.
Performance Data
Modeled
Actual
Energy Use Energy Use
Month
in kWh
in kWh
September 2007
22,510
17,492
October 2007
20,252
14,243
November 2007
17,460
10,399
December 2007
17,392
8,386
January 2008
17,544
4,490
February 2008
15,345
15,501
March 2008
18,509
16,724
April 2008
19,715
21,332
May 2008
22,751
20,473
Table readings were obtained from the building
management system and compiled by an independent third-party commissioning agent.
Performing Buildings
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Building Management System
Z e r o Wa t e r D i s c h a r g e
The Spectral Office is a zero water discharge
building with 100% rainwater harvesting
where rainwater is discharged through wells
into underlying aquifers. An in-house 10,000 L
sewage treatment plant has been installed
for waste and soil. Because there are no
municipal sewage mains in the area, the
plant is essential and helps in recovering the
treated water for gardening, air-conditioning
cooling towers makeup and flushing.
Municipal water intake is 6500 L per day.
The sum of gray and black water generated
in the building is 5554 L per day, which is
sent to the plant. The treated water from
the plant is apportioned 4700 L per day for
cooling tower makeup, 1620 L per day for
flushing and 854 L per day for gardening.
The solids will be pumped out of the plant
annually and used as manure.
Municipal
Water Supply
6500 L per day
Storage Tank
The services systems operations
are coordinated through a Webbased advanced building management system. Only two operation
staff members are employed to
handle day to day tasks. The operation parameters can be accessed
from any of the 150 workstations
in the building and provide feedback to occupants. The feedback
has been useful in upgrading the
HVAC system for winter heating.
At ambient temperatures below
24°C (75°F), the building operated
in free-cooling mode with a 100%
open fresh air and exhaust air
damper at all air-handling units.
These have been corrected for the
winter heating mode operation
by energizing the heating coils at
ambient temperatures below 20°C.
Payback
Domestic Use
Miscellaneous
Utilities
6060 L per day
340 L per day
100 L per day
Sewage
Treatment Plant
7174 L per day
Toilet Flushing
Landscaping
1620 L per day
854 L per day
Soft Water to
Air-Conditioning
Makeup
Cooling Towers
4700 L per day
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Prior to construction of the building, analysis of the total construction cost was carried out to determine the anticipated additional
impact due to incorporation of
energy-efficient measures such as
the high-efficiency chiller, energy
conservation strategies for airhandling units, lighting controls,
low-e double glass, wall insulation
and the sewage treatment plant. The
cost of the green building was $1.1
million, approximately 8% above a
similar conventional building. The
energy simulation predicted a payback period of less than four years.
With rising energy costs and anticipated greater energy savings than
predicted, the payback period may
be reduced to three years.
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Lessons Learned
Overcoming Climate Careful building
orientation, optimum window sizing, lowe double glass and envelope insulation
demonstrate that, even in the hot and dry
climate of northern India, careful design
can minimize heat ingress.
Design Discipline It is surprisingly easy
to save large amounts of energy and
water by imposing discipline on the whole
design and build team and by holding
regular design coordination meetings with
a clear mandate on achieving targets.
The design team met regularly to discuss
the challenges posed in sustainable construction which spawned new ideas and
ensured better coordination of the design
elements. For example, ideas for extensive use of waste, such as broken china
mosaic tiles on the roof and construction
debris as the sub-base for the flooring,
originated from these meetings.
Occupant Feedback Employees enjoy the
building’s indoor air quality and daylight.
Although the building is closely connected
to the community with residential and commercial areas near one another, individuals
often choose to stay in the building during
their lunch break. When compared to previous office situations, employee absenteeism has dropped, and productivity has
increased.
The building takes advantage of more than 300 days of bright sunshine annually
in Noida, India.
Although India is one of the world’s
top 10 energy consumers, the country is taking measures to increase
energy efficiency. According to The
Times of India, industry professionals expect the number of green
building projects in India to increase
from the current 164 to more than
2,000 by 2012. As a role model for
future developments, the Spectral
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Office contributes to this growing
sustainable trend. •
The air-conditioning load is half that
of a similar office building in the area.
B u i l d i n g s F a l l 2 0 0 8
Finding Local Sources Obtaining sustainable building materials from local sources
was problematic. The building team had to
hunt for vendors for bamboo flooring, low
VOC paints, low flow fixtures and material
made of recycled components.
About the Authors
Prem C. Jain, Ph.D., is chair of the Indian
Green Building Council and chair and
managing director of Spectral Services
Consultants in Noida, India.
Ashish Rakheja is cochair of the Indian
Green Building Council’s technical committee and chief operating officer for Spectral
Services Consultants.
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