MAY 2012: Construction and functioning of buildings has a profound effect on the environment. Buildings account for 40 per cent of our total energy requirements. These need to save energy, in order to reduce CO2 output and protect the environment.
In view of this, constructing green buildings is becoming a standard practice today. Compared to conventional buildings, a green building promotes healthier living spaces for the occupants while ensuring that utility wastage (water, energy and other natural resources) is minimal.
A smart green building can be described as the convergence of technology and real estate applications. Devices and solutions are transferred onto a converged IP network disrupting traditional design, transforming the physical space into a service offering.
Integrated energy management systems support sophisticated power management and energy conservation, leading to long-term environmental sustainability. Lighting automation solutions are delivered over the converged IP network. Centralised monitoring and control of elevators, heating, ventilation and cooling (HVAC), and facilities help ensure that the building meets or even exceed performance standards. An added benefit is that with the knowledge of energy usage patterns, building operators can respond to power cuts and proactively manage the carbon footprint to build a sustainable and more energy-efficient environment.
Converging multiple functions onto system devices means reducing the number of IT equipment needed, use of systems that consume less power, and more efficient use of all equipment. This, in turn, makes a significant difference in operating costs.
What goes inside
The most advanced green buildings deploy a host of IT and electronic elements including wired and wireless networks, network controllers, BACnet and local operating network routers, gateways, automation controllers, sensors and sensor network controllers, variable air volume controllers, servers, workstations and browsers. The variety and performance of these components depend on the level of complexity of the building automation systems.
Controls and automation, sensors and energy-efficient lighting are the most important components of a green building.
Control and automation solutions help save on illumination costs. These allow integration of a range of services within a space, such as lighting, security, heating, ventilation, air-conditioning, home theatre, audio, motorised curtains and blinds. This gives the user the option of restricting the use of a product to only when it is required.
Sensors can detect motion in a room or the level of available natural light, and adjust artificial lighting
levels suitably. These can also pick up infrared commands from remote controls for added flexibility.
LED lighting is highly energy-efficient. It is one of the most sustainable and longest lasting lighting sources available today. It facilitates reduction in CO2 emissions, in addition to saving energy and maintenance costs.
Taipei 101 building in Taiwan has achieved a 10 percent saving in electricity usage,water consumption and waste over the past two years. Its energy consumption is 30 per cent more efficient than an average building. All of this results in approximately $700,000 of savings in annual energy costs.
The building has a fully integrated energy management and control system installed.Intelligent connectivity enables the integration of power monitoring,generator management, chiller control, lighting control, zone pump variable-speed drive security management, fire alarm systems and car parkingmanagement. Time controls have been placed on extractor fans that previously ran continuously.Every thermostat and variable air volume box was placed after identifying a location for it.
The energy monitoring and control system by Siemens streamlines the operation and control of the HVAC equipment throughout the complex, optimising the entire energy usage. The efficiency of the cooling system has been increased by applying improved algorithms for the chiller plant and changing the sequence of operation.
(Source: Case study-Siemens helps TAIPEI 101 to become the tallest ‘green’ building in the world)
Most green buildings today work with independently controlled and managed lighting, HVAC and other loads. Some very advanced buildings provide loose integration at the data visualisation or dashboard level. This allows continuous monitoring of the different loads and corrective actions as and when desired. Some of these advanced systems allow interfacing with the utility grids, and present opportunities of demand response and dynamic energy pricing.
Intelligent IP-based networking
Using green networking solutions reduces not only networking costs but also general operating expenses such as office space and energy costs.
Cisco has designed an end-to-end solutions system to ensure effectiveness of green buildings. Its Smart+Connected utilities solutions use an intelligent IP-based network platform to address energy, water, and gas management and consumption, and thereby reduce carbon emissions, and increase efficacy. Building managers can plan and manage energy consumption based on real-time information and policy configurations.
The network building mediator provides the intelligence to interconnect and enable building systems such as HVAC, lighting, electrical, security, and renewables over the IP network to build smart and energy-efficient buildings of the future. NetApp has deployed this solution in conjunction with other systems and reduced energy consumption at its Sunnyvale location (USA) by 18 million kilowatt hours in 18 months. Apart from a reduced carbon footprint, the company has saved an estimated $2 million in energy costs.
The connected workplace solution provides a flexible working environment through the innovative use of unified communications, wireless network access and virtual private networks. Employees can work at a variety of locations while boosting workplace efficiency and reducing an organisation’s carbon footprint. Additionally, Cisco unified computing system solution unites computing, networking, storage access and virtualisation into a cohesive system. This approach decouples scale from complexity. The system reduces DC power consumption by 33 per cent, and single wiring connects to SAN or LAN. Also, there are zero-downtime operations and 40 per cent savings in infrastructure.
Cisco has recently launched EnergyWise—a technology that makes it possible for businesses to reduce carbon emissions, by managing energy consumption of devices on the network when they are not in use. Starting with IP-based devices such as VoIP phones and video cameras, Cisco will work with partners to extend this to computers and peripherals, and finally to improve energy utilisation–by systems such as lighting, heating, surveillance and access—throughout the building.
The connected real estate solution connects all real estate through interoperable building management solutions over an IP backbone. It thus enables the convergence of multiple proprietary networks that individually run elevators, lights, air-conditioning, security, power, water, voice, data and more. Building management systems are integrated with traditionally disparate control networks.
Monitoring and control
Building manager is a high-performance automation system for monitoring and managing a building’s devices and systems, including HVAC, lighting, hydraulics, water, electrical equipment and more.
Honeywell’s Building Manager utilises open system standards to seamlessly integrate control and information systems within an enterprise. It gives single-window control over building operations and all the relevant data to maximise building performance. In addition, Building Manager captures current and historical data for advanced analysis and reporting.
High-performance HVAC digital control systems help improve the facility’s indoor environment while cutting energy and equipment costs, and feature sequences of operations that leverage Honeywell’s applications expertise.
Building Manager has user-configurable pull-down menus and toolbars that allow intuitive navigation and fast access to critical information. By integrating Honeywell’s advanced human-machine interface (HMI) Web technology, the user has secure access to his building systems from anywhere. He can authorise who can view equipment status, check current temperatures, and control lighting and comfort setpoints for their areas.
Batteryless wireless sensors
Be it is a retrofit scenario or a new build, maintenance-free wireless sensors and switches play an important role to open up energy efficiency potentials in buildings.
EnOcean has developed a technology that combines micro-energy converters with ultra-low-power electronic circuitry and reliable wireless communications. The technology was developed based upon the understanding that, where sensors capture measured values, the state of energy constantly changes. Also, when a switch is pressed, the temperature alters or the luminance level varies. Since all these operations generate energy, it can transmit wireless signals.
Consequently, instead of batteries, EnOcean uses miniaturised energy converters to supply power: linear motion converters, solar cells or thermal converters. This technology is the basis for creating self-powered wireless sensor solutions, which help improve the management and usage of energy in buildings and industrial applications.
Vendors are using this self-powered wireless technology in a range of various products for buildings, from room thermostats to wireless window contacts to solar-powered presence-detection sensors. They can, for example, help increase the energy efficiency of the building, while simultaneously offering a high degree of flexibility, since no complex cabling is required for their installation. That not only reduces the cost of putting the systems in place but also improves usability for home-owners since the wireless switches can be installed wherever they are needed.
In comparison to conventional systems, the implementation costs for batteryless, wireless solutions are reduced by 10 per cent as no wires are necessary. These measures reduce costs in new constructions by 15 per cent and in retrofits by 70 per cent.
In green buildings, integrators of energy harvesting devices have the flexibility to place controls wherever they will achieve optimal efficiency—without meddling with the structure. For example, installing occupancy sensors that turn off lights in vacant rooms can save up to 40 per cent on energy and operating costs. The payoff period of energy harvesting wireless solutions in a building automation system is between two and three years.
More than 250 companies worldwide from the building sector have come together to form the EnOcean Alliance and establish automation solutions for sustainable building projects. Currently, there are more than 850 products available, which are all interoperable and based on the energy harvesting wireless technology. Green buildings solutions based on this technology are:
1. Batteryless, wireless switches to control lighting and shading
2. Batteryless outdoor light sensors, which automatically match lighting to daylight
3. Occupancy sensor, which adjusts temperature and turns lights off when a room is not in use
4. Room temperature sensor for minimal energy consumption
5. Climatic (humidity and CO2) sensors, which monitor indoor air quality
6. Position sensors—e.g., window handle and window contact—that cut out
heating and air-conditioning when windows are open
7. Central control on a touch panel or PC
8. Remote monitoring and control by a mobile phone or on the Internet
Energy-saving LED lighting
Lighting is one of the most attractive and easy ways to save on your electricity bills. It consumes 19 per cent of all electricity in the world. Replacing energy-inefficient lighting with green alternatives has an immediate impact on energy use, CO2 emissions and the environment.
For light sources, Philips is developing solidstate lighting solutions with increased efficiency and lower costs. In controls, it is developing a range of standalone solutions with dimming, occupancy and daylight sensing applicable to small- and medium-sized buildings. For large buildings, Philips is developing fully networked (wired and wireless) solutions that interface with standard building management systems and include advanced daylight harvesting using controllable motorised blinds and shades. It is also working on interface with the building HVAC systems with integrated control strategies that can optimise the overall energy consumption.
Philips’ Quadra LED and Quadra LED2 luminaires offer up to 45 per cent energy savings compared to the traditional, non-LED based office lighting equipment used in India. The company also offers LED-based lighting solutions for retail and hospitality sector.
Lighting automation systems use occupancy-based lighting control, electronic dimming ballast-based lighting control and programmable time scheduling.
A typical lighting control system consists of:
1. A central processor
2. Light and energy management software
3. Built-in timeclock for scheduling light control
4. Dimming modules for dimming electric light
5. Occupancy sensors for switching off light in vacant space
6. Daylight sensors for daylight harvesting
7. Automated shades for controlling daylight
8. Wall stations for manual control
9. IR or RF remote for personal control of light level
The integration of all these components can dim light to the right level for every activity, thus saving energy and extending lamp life. Timer control can turn light on/off and dim light level automatically during non-peak hours to prevent wastage. Sensor control can prevent wastage of lighting energy in vacant space. Daylight sensors can adjust electric light according to incoming daylight level. Automated shades block sun glare and solar heat gain, thus lowering energy consumption of air-conditioners and providing a comfortable environment. Wall stations or remote controls allow personal control of light level according to individual tasks.
Lutron offers total lighting control solutions for green buildings. The costdepends on the project size, number of circuits and complexity of the system. The payback period for a simple system can be as short as one and a half year to two years. For a complicated system, the payback period ranges from three to five years.
While solar energy run air-conditioners can provide respite from the scorching heat, these also bring along environmental benefits such as reducing greenhouse gas emissions.
As reported in Times of India, all 40 air-conditioners in the Gujarat Pollution Control Board (GPCB)’s new building run on solar energy. This is the first 100 per cent solar building in India wherein electricity generated from sunlight also powers as many as 600 fans and 1000 CFL tubelights besides the ACs. After investing Rs 10 million in the power system, the GPCB claims that the investment made will be recovered in five years. The investment is inclusive of a ten-year operation and maintenance contract for the building. The solar panels set up atop the building over 2000sq.m space generate 80kW energy.
Chillers and hybrids are the two solar AC variants. Solar-powered absorption chillers cool and heat water through condensation and evaporation. Air temperature drops as it passes across a saturated material. The motor and fan are solar energy powered.
The hybrid system combines direct current and photovoltaic technologies. It automatically switches between battery and solar power as needed. In hybrid mode, the system taps sunlight to charge the batteries. When not in hybrid mode, AC power charges the batteries while the system runs on a battery backup. GreenCore Air has designed such a solar-powered model.
Switch worth the effort
For building managers and owners, the challenge today is to design, build and operate buildings in the most efficient, economical and environmentally responsible way. Investing in green building technologies is the answer for this need.
Most green buildings in India cost a premium of 4-5 per cent, but yield ten times as much over the entire life of the building. The typical payback period for projects in India is estimated to be three to seven years, according to the World Green Building Council.