Innovations in green airport construction
Prayagraj Airport’s new terminal in Uttar Pradesh has been built based on the green airport construction under the GRIHA-IV rating for its use of solar power, intelligent energy systems and water management. A building management system (BMS) has been implemented for control of HVAC equipment for efficient operation and energy saving. Further, plants and shrubs have been planted as part of the landscape area, besides plantation inside the terminal building. Moreover, seven recharge pits have been developed for rainwater harvesting. The project also features 50 kW capacity solar panels on the rooftop, low power consumption LED lights, VFD chiller, secondary pumps and automatic light control through occupancy sensors in public areas, such as rest rooms—all to save energy. All the AHUs have been provided with VFD facility. Also, a 50-kld sewage treatment plant has been installed and 100 per cent treated water is used for irrigation and flushing.
Pankaj Tare, General Manager-Projects, Airports & Station Modernisation, Tata Projects, elaborates on the innovations that helped the new terminal go green:
- Exterior wall construction (U-value taken from DBR): AAC block with plaster. Overall U-value of exterior wall is 0.78 W per sq m°K° (0.137 Btu per hour-sq ft F).
- On-site/off-site renewable energy system installation to offset a part of the annual energy consumption of internal artificial lighting and HVAC systems.
- Monitoring CO2, temperature and RH in air-conditioned spaces.
- Two-speed, Pony motor, VFD-controlled cooling tower fan control.
- Fulfilling mandatory requirements of ECBC; all fans BEE-star rated.
- Roof construction with insulation (U-value taken from DBR). Overall U-value of roof is 0.26 W per sq m°K (0.046 Btu per hr-sqft F)
- Window to gross wall ratio: 36 per cent (without fritted glass)
- 100 per cent of outdoor lighting (lamps + lamp housing) meets luminous efficacy requirements (at least 75 lumens per W).
- Lighting for all exterior applications controlled by photo sensor or astronomical time switch.
- Transformer efficiency calculation at 50 per cent and 100 per cent load with losses meet ECBC requirements.
- Power cabling sized to ensure power distribution losses don’t exceed 1 per cent of total power usage.
- Provision of photo sensor interlocked with artificial lighting within perimeter spaces capable for 50 per cent reduction in power output for day-lighted spaces greater than 250 sq ft.
- Artificial lighting meets minimum uniformity ratio of 0.4.
- Occupancy sensors for all public and non-public areas.
- Provision of energy meter for utility grid and advanced energy meters: smart/advance energy metering for HVAC plant, UPS, lighting.
- Suction piping for split system has minimum R-2 insulation; also, all insulation is CFC and HCFC-free.
- To offset 0.5 per cent of annual energy consumption of internal artificial lighting and HVAC,solar panels of capacity 50 kva (45 kw considering 0.9 as DC to AC conversion) have been installed on the roof, with total annual production of about 63,289 kwh
- Use of materials in building insulation, HVAC, refrigeration and firefighting with low ozone depleting potential.
- Fire-suppression systems and fire extinguishers free of halon.
- Indoor noise levels within acceptable limits (NBC 2005) and key noise sources (DG sets, chiller plants) have sufficient acoustic insulation.
- Use of chiller plant fulfilling the ECBC code.
- Fresh air inputs and treatment meeting the CPCB National Ambient Air Quality Standard for fresh air as well as ASHRAE standards. PM10, ozone and CO2.
- Use of low-VOC paints and other compounds in interiors.
- Electrical car charging points for at least 5 per cent of parking spaces.
- E-waste recycling.
- STP installed.
- Installation of digital water meters for municipal water, borewell, treated water from STP (at outlet), rainwater reuse.
- Water fixture flow rates: Water closet- 4/2 LPF; urinals- 1.5 LPF; lavatory faucets- 4 LPF; kitchen sink - 6 LPF; showers- 6 LPF.
- Recharge of surplus rainwater into aquifer (through appropriate filtration).
Water-saving landscape techniques including selection of native and drought-tolerant species along with drip irrigation system and time-based controller for landscaping.