To build a net-zero energy building in the Indian climate and halve the carbon emission values by following the building code and achieve a high LEED rating is a gigantic task. It’s all possible with the excellent use of insulating materials like polyurethane, harnessing the daylights and also by designing the building considering the ways to maximise the utilisation of natural resources. Council’s lead partner, Covestro has managed to achieve all these in just one project.
The Covestro EcoCommercial Building (ECB) in Greater Noida achieved LEED-NC Platinum with highest ratings in the world during the certification (64 out of 69). The building’s energy needs are fulfilled by the photovoltaic panels on the roof, which produces more energy than consumed by the building over a full year. The excess energy is fed to the adjacent building in the same campus. This is made possible, not only by creating large amount of renewable energy, but also by reducing the energy consumption of the building by improving the efficiency of the building by insulating materials like polyurethane.
Since the project integrates the best-in-class solutions for energy efficiency, sustainability, innovative technologies, among other solutions, it allows construction of buildings to be able to operate within lower consumption of natural resources, adapting to weather conditions in any place worldwide, and providing renewable energy sources, treatment and reuse of rainwater. The ECB, which became the first net-zero energy building in India, was conceived as a prototype, being able to host visitors, training courses and sustainable construction events.
- Efficient building envelope design: The purpose of the thermal envelope is to prevent heat transfer from the interior of a building to its exterior in winter and vice versa in summer. Owing to the cold winter and extremely hot summer of the site, ECB was enveloped from wall, roof and foundation, including the floor area.
- Climatically-responsive facade concepts: This concept includes a roof that extends beyond all four sides of the building, protecting it from direct sun and reducing heat gain
- Toughened glass windows: Efficient glazing balancing low thermal conductivity and shading coefficient; argon filled toughened glass windows with internal shades to avoid the need for cleaning.
- Thermal mass and insulation materials: A combination of polyurethane foam, mineral wool, air gap and coba bricks were utilised as insulating materials.
- Lighting and daylighting controls: Since ECB is a day-use building, daylighting is maximised in all occupied spaces. Simulation software was used to evaluate the impact of various shading devices to minimise glare indoors. The main objective of simulation was to ensure that the use of blinds/curtains on windows not compromise occupants’ visual comfort. Integrated motorised blinds are achieving these goals, and no problems have been reported regarding their operation. An energy-efficient lighting system with daylighting controls provides additional light when daylighting is not sufficient. Occupancy sensors in normally unoccupied areas like storage areas, toilets and mechanical rooms minimise lighting use. Lighting controls ensure minimum internal heat gain and reduced air-conditioning load in those spaces.
- HVAC system equipment selection: The HVAC system of a building consumes around 40 per cent of the total energy consumed by the building. Hence, the best way to reduce the energy requirement is to target on the HVAC by improving the building insulation by Polyurethane to reduce the heat loss and also by choosing the HVAC equipment, which utilises the energy in the most efficient way.
- Solar PV: ECB in Greater Noida uses 57kW crystalline silicon grid-connected solar system installed on the roof for generating emission-free, on-site energy generation. The solar panels are aligned in the direction of the sun to harvest the maximum efficiency.