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NZEB tour | UNNATI: An office building for GAINWELL-CAT

The presentation was conducted in one of UNNATI’s daylit conference rooms

A tour of UNNATI, an office building for GAINWELL-CAT in Greater Noida, was conducted on 14th September 2019.  The tour was led by members of its design team- including Anmol Ahuja from ABL architects, Mariyam Zakiah, the green building consultant from EDS and Vevaik Mahajan, the MEP consultant from UEDC- as well as UNNATI’s facility team.  The tour was conducted in two batches over the day, with 22 participants including professionals, academicians and students.

GAINWELL-CAT is an earth-moving equipment manufacturer and the 3750 sq. m office building -UNNATI- sits within their 5 acre campus, that also houses the manufacturing set-up, in an industrial district. With an EPI of 60 kW/sq.metres/year, the building exemplifies energy savings through climate-responsive design, which is one of the most important aspects of achieving the nearly-zero energy target. It also received the highest LEED certificationPlatinum- under the stringent v4 BD+C rating system.

Participants explore UNNATI’s courtyard


Even as they entered the campus, participants noticed its cooler microclimate compared to the typical stifling heat in the industrial surroundings. Peripheral trees, an eco-reserve and rooftop garden reduce heat island within the campus. Through the day, many such low-tech but high-impact sustainability features- key strategies for achieving the nearly-zero target- were introduced to the participants.

An initial presentation by the design team outlined the building features, including passive design strategies like courtyard planning, daylighting and optimized building envelope and complementing active systems like low-energy radiant cooling and the 100 KW rooftop solar PV system. After this brief, participants were given a detailed tour of the building along with demonstrations of various building systems.

To demonstrate the daylight penetration, all the electric lights were turned off, yet daylight from the courtyard and windows ensured that floor plates remained 90% lit. Participants also learned about the building’s unique facade that uses Truss-refinforced concrete (TRIC)- that not only provides insulation, but is also designed to serve as a light-shelf, shading device and even to hold HVAC ducts and other services.

Participants learn about the radiant cooling system installed in UNNATI

One of the highlights of the building is its hybrid HVAC system which is a combination of water-cooled air handling units and floor-embedded radiant cooling system. Participants learned to recognize the components of this system, including the circulation loop. They grasped the benefits of underfloor radiant cooling coupled with fresh air supply, which reduces the total volume of air to be cooled and thus saves energy.  They understood how the building operates to ensure that the systems perform optimally. For instance, doors and windows are tightly shut and humidity sensors have been deployed to reduce the chances of condensation. As per the adaptive thermal comfort model, the system is set at 25°C-26°C, ensuring adequate comfort conditions. Personal cross-flow fans at every desk provide users the opportunity to control air speeds.

Studying the BMS further helped participants appreciate how all the different building systems integrate to ensure high performance.

Here is what participants are saying about the tour-

The presentation held my attention! My biggest takeway was how passive design elements help in facilitation construction and operation of green buildings.

Vidipt Saroj Kalra
Student at OP Jindal Global University

Touring UNNATI was an amazing experience! It was insightful to learn how the design team took an integrated approach towards the external building envelope, HVAC design, MEP and even the interiors!

Nidhi Rai Jain
Research associate, Alliance for an Energy Efficient Economy (AEEE)

Thanks for organizing the tour. It is a great way to see live implementations of various aspects of sustainability that we read/talk about. I gained a new perspective on the importance of air flow for thermal comfort as well as use of radiant cooling systems in humid conditions

Barun Aggarwal
CEO, BreatheEasy Consultants Pvt. Ltd