H i g H P e r f o r m i n g B u i l d i n g s fa l l 20084 4 fa l l 2008 H i g H P e r f o r m i n g B u i l d i n g s 4 5

B u i l d i n g At A g l A n c e

B u i l d i n g t e A m

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

owner spectral services Consultants Pvt. ltd.

Architect ABrd Architects

fundamental and enhanced Commissioning Agent godrej & Boyce mfg. Co. ltd.

Construction manager Consortium Consultancy

energy Consultant environmental design solutions

leed facilitation Cii – godrej sohrabji green Business Centre

meP Consultant spectral services Consultants Pvt. ltd.

interior designer Payal Jain inc.

Civil Contractor Ahluwalia Contracts (india) ltd.

HVAC Contractor suvidha engineers india ltd.

electrical Contractor Ahluwalia Contracts (india) ltd.

Building management system Contractor imetrex Technologies ltd.

Public Health engineering Contractor d s gupta Construction Pvt. ltd.

c A s e s t u d y s p e c t r A l s e r v i c e s c o n s u l t A n t s c o r p o r A t e o f f i c e

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 s h r A e ;

Less HeatDaylight WithA n d A s h i s h r A k h e J A , m e m B e r A s h r A e

India is one of the

world’s top 10 energy

consumers, and

growth is expected around

6% annually over the next

few years. However, Indian

companies are working to

cut energy consumption. The

Spectral Services Consultants

Corporate Office in Noida,

India, achieves over 36%

energy savings mainly by pro-

viding daylight to occupants

throughout the day without

gaining heat from the sun.

H i g H P e r f o r m i n g B u i l d i n g s fa l l 2008 fa l l 2008 H i g H P e r f o r m i n g B u i l d i n g s4 4

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.

H i g H P e r f o r m i n g B u i l d i n g s fa l l 20084 6

Building envelopeTo accomplish the daylighting strategy, the building faces north-south, the optimal orientation for a building on the Indian subcontinent. Heavy glaz-ing 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, opti-mized 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 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 mon-soon season and 45of in the winter. in a year, 90% of days are bright and sunny.

n o i d A , i n d i A

The fresh air quantity is 30% higher than recommended by Standard 62.1-2004.

The payback period is expected to be less than four years.

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H i g H P e r f o r m i n g B u i l d i n g s fa l l 20084 8

Recessed windows with fins cut down on direct solar heat gain.

HPB.hotims.com/21087-15

solar reflectance index). The resulting U-value is 0.063 Btu/h·ft2·°F.

harnessing sunlightDespite the hot and humid climate, the 16,000 ft2, five-floor office build-ing 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 work-ing 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 through-out the day, the louvers reduce air- conditioning loads and glare on workstation computers. The louvers’ angle was computer simulated to study year-round performance.

night lightingIn the evening, an advanced light-ing management system automati-

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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 air-handling unit in the building is provided with an ultrasonic humidi-fier and electrical heater installed within the supply air duct. The

building’s management system runs the entire operation, maintaining

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 inter-nal lighting power density is 0.63 W/ft2, approximately half the IESNA recommended lighting power den-sity of 1 W/ft2 for offices.

indoor Air QualityA 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

A south-inclined skylight encompasses the entire atrium and harnesses daylight.

diverted to authorized disposal agencies. To reuse resources, furni-ture 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.

fire safetyEven 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.

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 econo-mizer cycle for free cooling of the indoors during fair weather.

reusing materialsDuring construction, 96.6% of the building waste was collected and

e n e r g y u s e

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 refrigera-tion. 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 refrig-eration. 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-han-dling units on all floors coupled to variable frequency drive, and internal air distribu-tion through variable air volume boxes.

The baseline yearly electrical energy demand for the building, per Ansi/AsHrAe/iesnA standard 90.1-2004, 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

Month

Modeled Energy Use

in kWh

Actual Energy Use

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 inde-pendent third-party commissioning agent.

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).

Below Permanently inclined louvers block direct sunlight and reduce air-conditioning loads.

d Ay l i g h t p e r f o r m A n c e

More than 75% of the building’s inte-rior is daylit.

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Building management systemThe services systems operations are coordinated through a Web-based advanced building manage-ment system. Only two operation staff members are employed to handle day to day tasks. The oper-ation parameters can be accessed from any of the 150 workstations in the building and provide feed-back 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.

paybackPrior to construction of the build-ing, analysis of the total construc-tion cost was carried out to deter-mine the anticipated additional impact due to incorporation of energy-efficient measures such as the high-efficiency chiller, energy conservation strategies for air-handling 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 pay-back period of less than four years. With rising energy costs and antici-pated greater energy savings than predicted, the payback period may be reduced to three years.

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.

Z e r o w At e r d i s c h A r g e

municipal water supply

6500 l per day

miscellaneous

340 l per day

sewage treatment plant

7174 l per day

landscaping

854 l per day

domestic use

6060 l per day

toilet flushing

1620 l per day

utilities

100 l per day

soft water to Air-conditioning

makeup cooling towers

4700 l per day

storage tank

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Office contributes to this growing sustainable trend. •

Although India is one of the world’s top 10 energy consumers, the coun-try is taking measures to increase energy efficiency. According to The Times of India, industry profes-sionals 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

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 commit-tee and chief operating officer for spectral services Consultants.

A B o u t t h e A u t h o r s

overcoming climate Careful building orientation, optimum window sizing, low-e 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 con-struction which spawned new ideas and ensured better coordination of the design elements. for example, ideas for exten-sive 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 com-mercial areas near one another, individuals often choose to stay in the building during their lunch break. When compared to previ-ous office situations, employee absentee-ism has dropped, and productivity has increased.

finding local sources obtaining sustain-able 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.

l e s s o n s l e A r n e d

The air-conditioning load is half that of a similar office building in the area.

The building takes advantage of more than 300 days of bright sunshine annually in Noida, India.

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