Energy efficiency is a multifaceted topic. Here, we discuss the nuances of making a building energy efficient.
In present times, energy efficiency has gained momentum in the wake of increasing threat of global warming and accelerated depletion of natural resources due to rapid globalization. This has led the industries to take cognisance of potential benefits of practising energy efficiency in its business activities.
In the building sector, buildings are the largest energy consumers in the world. They account for around 30 per cent of global carbon emissions, and over one-third of ultimate energy use. So, energy efficiency plays an important role from the initial stage of planning to the final stage of product delivery. An energy efficient building is one that delivers the same level of comfort and operational conditions as a conventional building but by consuming less energy. Making energy-efficient buildings is need of the hour for taking a sustainable step in the direction of green future.
Building efficiency must be considered as convalescing the performance of a complex system designed to provide occupants with a comfortable, safe, and attractive living and working environment. This requires superior architecture and engineering designs, quality construction practices, and intelligent operation of the structures. Increasingly operations will include integration with sophisticated electric utility grids.
The major areas of energy consumption in buildings are heating, ventilation, and air conditioning; lighting, major appliances (water heating, refrigerators and freezers, dryers); and a noteworthy fraction remaining in sundry areas including electronics. In each case there are opportunities both for improving the performance of system components and improving the way they are controlled as a part of integrated building systems.
Expressing thoughts on energy efficient buildings, Dr Niranjan Hiranandani, Founder & CMD, Hiranandani Group says, “Making buildings more energy efficient is needed to be done at two levels. First, at the planning stage – ensuring that the under construction stage does not pollute the environment as also works on lower levels of power and water usage. Secondly, once completed, efficient usage is a simple equation – increase number of human resources while ensuring lower levels of electricity and water consumption as also proper treatment of garbage and sewage. Being energy efficient has to be a way of life, and not just a check-list of things to be done.”
Making buildings more energy-efficient
With the increasing focus on attaining energy efficiency in constructing new buildings as well as existing retrofits, the Indian building sector has been constantly investing in R&D on sustainable and energy-efficient building techniques as well as material which have minimal environmental impacts along with durability for endurance of the structure. In India, energy efficient buildings are popularly called as “Green Building/Net-Zero Building”.
Adopting sustainable design
Today, building designing adds to serious environmental problems because of excessive consumption of energy and other natural resources. The close association between energy use in buildings and environmental damage occurs because energy intensive solutions sought to construct a building & meet its demands for heating, cooling, ventilation & lighting cause rigorous depletion of important environmental resources. Nonetheless, buildings can be designed to meet occupant’s need for thermal and visual comfort at reduced levels energy & resources consumption. Energy resource efficiency in new constructions can be achieved by adopting an integrated approach to building design. Ar. Charanjit S Shah, Creative Group asserts that, “the various energy stimulation in respect of creating efficient and functional air-conditioned or non air-conditioned spaces based on most efficient wall and ceiling thermally insulated materials can be tested and stimulated with various tools of scientific understanding in creating energy efficient buildings of tomorrow. Today is the time when we need to understand and look beyond imagination in creating net zero energy buildings to avoid carbon emissions and to sensitise ourselves in using minimal thermal power energy produced through coal or diesel, choosing to use energy produced by other methods such as hydraulic or solar or wind energy.”
Ar. Naresh V Narasimhan, Architect-Principal, Venkataramanan Associates states that, “Design of buildings should consider the equation of energy consumption versus energy supply. These are a few strategies that can be incorporated in any design to make it more sustainable like incorporating energy-efficient materials and designs that are responsive to the site conditions, climate and function. Using fenestrations and shading elements to maximize daylight and minimize heat gains and using Insulation materials with good thermal mass properties to reduce energy used for heating and cooling. Also, using building management systems (BMS) and similar systems to measure analyse and reduce energy consumption.
Implementing technological advancements
In recent years, building energy management has become has gained popularity. The techniques used in automatic control have evolved from static schedules specified manually into real-time sensing through wireless sensor network. The demand for a dedicated platform for building energy management systems has materialized presently. Numerous proposed platforms focused on the high-level architecture and are based on existing standards and technologies. Leena Ragade Gupta, Studio Archohm adds that, “There is an unimaginable diversity and range of mechanisms for making buildings energy efficient are now known; which ones are employed, really depends on the context and the mindset of the stakeholders, among whom the designer is like a foreperson in a grand jury. At studio archohm, we believe in the simplest and most easily doable mechanisms. Then we augment them with techno-savvy and sophisticated ones on a ‘need’ basis. In the Indian tropical climate, the deep and clear understanding of the characteristics of heat/light/glare of all cardinal directions create appropriate responses wherein a building shades itself wins us half the battle. Additionally, our insight into how air movement happens enables a responsive placement of voids, cut-outs and openings in the walls to draw in cool air and throw out hot air. Vernacular architecture has provided ample clues in this arena and it is for us to pick cleverly and manipulate these elements. We also use simulated models and softwares to sort these. There is a need for actively promoting and practicing the use of local material is a significant, albeit less tangible means of reducing energy consumption. Buildings also need constant monitoring and maintenance like automobiles do, so its efficiency is also kept efficient.”
Obtaining green rating & certifications
Developers, Architects and construction professionals are now actively brain-storming on ways to build energy efficient structures cost-effectively with help of green building certification and rating agencies such as GBCI, IGBC, LEED and such for “going the green way” construction process. “New buildings should start by optimising the building design and envelope in order to reduce energy demand. Buildings on average have a life span of 50-60 years. Incorporation of passive design and high performance envelope are measures with benefits spanning the entire life cycle of the building. Next, the electro-mechanical systems (like artificial lighting, HVAC systems etc.) in the building should be optimized to reduce energy consumption while ensuring healthy living and working conditions for building occupants. Energy efficiency can be improve by conducting an energy audit of their artificial lighting, HVAC systems and other electro-mechanical systems with the help of an energy auditor,” says Apoorv Vij, Sr. Manager, GBCI.
Mala Singh, CMD, PEC Greening India says that, the comprehensive implications of global-warming and the resultant environmental degradation are too chilling to ignore. To ensure consistent human survival and advancement, we must conserve Earth’s natural resources to the best of our abilities. “An efficient building is one which conserves energy, reduces unnecessary energy consumption, greenhouse gas emissions and demand for non-renewable resources. They provide significant savings over conventional buildings.”
As a result, energy efficiency is an all-encompassing, practical, need of the hour. Apply local climate-sensitive passive design techniques; such as building form, orientation, surface color, sun shading, building envelope insulation, air tightness, ventilation, etc. All measures to be taken to ensure an efficient building envelope are outlined in the Indian Green Building Council (IGBC) norms, she further adds.
Embracing HVAC technology
J M Bhambure, Executive Vice President – R&D and Technology, Blue Star Limited says that, “We need to have a multi-pronged approach, comprising of use of energy efficient equipment, buildings designed for lower heat load, regulations & codes and addressing the behavioural pattern of the users. While a lot of work has been done on efficiencies of the equipment through mandatory regulations and certifications, steps have also been taken to initiate certification at a building level through green building movement, which addresses reducing the heat load as well as use of efficient equipment.”
Research is also needed on the use of air coolers in hot and dry climate, with change management initiatives air conditioners are not the only cooling means. In moderate and cold climate conditions, where internal heat load is high, measures can be taken, using recirculation of water and dissipating the heat. Steps can also be taken to incentivise, by using differential power tariff for thermal storage systems, which have an advantage of lower energy consumption due to lower ambient temperatures at night. An integrated and systems approach has to be taken by the architects, system designers and policy makers.
“Thought process for energy efficiency starts right from planning stage, extends to design stage and execution, then functioning. Right from site selection to passive architectural design to optimized building services design – all holistically is crucial to reduce energy demand. Incorporating the right energy conservation measures, latest HVAC technologies such as radiant cooling, chilled beams etc will result in reduction in energy consumption”, states M. Selvarasu, Director, Lead Consultancy and Engineering Services.
Being energy efficient has to be a way of life, and not just a check-list of things to be done.
Dr Niranjan Hiranandani, Founder & CMD, Hiranandani Group
Energy resource efficiency in new constructions can be achieved by adopting an integrated approach to building design.
Ar. Charanjit S Shah, Creative Group
Design of buildings should consider the equation of energy consumption versus energy supply.
Ar. Naresh V Narasimhan, Architect-Principal, Venkataramanan Associates
There is a need for actively promoting and practicing the use of local material, which is a significant albeit less tangible means of reducing energy consumption.
Leena Ragade Gupta, Studio Archohm
Incorporation of passive design and high performance envelope are measures with benefits spanning the entire life cycle of the building.
Apoorv Vij, Sr. Manager, GBCI
Research is also needed on the use of air coolers in hot and dry climate, with change management initiatives as air conditioners are not the only cooling means.
J M Bhambure, Executive Vice President – R&D and Technology, Blue Star Limited
Energy efficiency is an all-encompassing, practical, need of the hour.
Mala Singh, CMD, PEC Greening India
Incorporating the right energy conservation measures, latest HVAC technologies will result in reduction in energy consumption.
Selvarasu, Director, Lead Consultancy and Engineering Services.