The inoculation treatments were control, indigenous mycorrhiza, G. mosseae, G. etunicatum, G. intraradices, G. caledonium, G.fasciculatum and a mix of these species. The seedlings were grown in a greenhouse for 32 days before being transferred to the main field plots. The experimental plots were randomized with three replicates. Each crop species was tested in a separate experiment. Seedling survival yield and nutrient uptake were measured. Fruits were collected several times and leaves and root samples were analyzed for nutrient content at flowering. Roots were stained and examined for the presence and degree of mycorrhizal infection according to Gioannetti and Mosse . This document provides best practice guidance and energy efficiency recommendations for the design, construction, and operation of high-performance office buildings in India. Through a discussion of learnings from exemplary projects and inputs from experts, it provides recommendations that can potentially help achieve enhanced working environments, economic construction/faster payback, reduced operating costs, and reduced greenhouse gas emissions. It also provides ambitious energy performance benchmarks, both as adopted targets during building modeling and during measurement and verification . These benchmarks have been derived from a set of representative best-in-class office buildings in India. The best practices strategies presented in this guide would ideally help in delivering high-performance in terms of a triad—of energy efficiency, cost efficiency,4x8ft rolling benches and occupant comfort and well-being. These best practices strategies and metrics should be normalized—that is, corrected to account for building characteristics, diversity of operations, weather, and materials and construction methods. Best practices should start by using early design principles at the whole building level.
Optimal energy efficiency can be achieved through an integrated design process , with stakeholder buy-in from the beginning at the conceptual design phase. Early in the project, the focus of the stakeholder group should be on maximizing energy efficiency of the building as a whole, and not just on the efficiency of an individual building component or system. Through multi-disciplinary interactions, the design team should explore synergies between systems such as mutually resonating strategies; or sweet spots between inharmonious strategies. Buildings are the most energy efficient when designers and operators ensure that systems throughout the building are both efficient themselves, and work efficiently together. Systems integration and operational monitoring at the whole building level can help push the envelope for building energy efficiency and performance to unprecedented levels. Whole-building systems integration throughout the building’s design, construction, and operation can assure high performance, both in terms of ensures the energy efficiency and comfort/service levels. A Life cycle Performance Assurance Framework emphasizes the critical integration between the buildings’ physical systems and the building information technologies. The building physical systems include envelope, HVAC, plugs, lighting and comfort technology systems. Whereas, building information technologies provide information on the design and functioning of the building physical systems. This can be done- first, by performing building energy simulation and modeling at the design phase one can estimate the building’s energy performance and code compliance; second, by integrating controls and sensors for communications, one can track real-time performance at the building phase, relative to the original design intent; and third, by conducting monitoring-based commissioning and bench marking during operations, one can ascertain building performance compared to peers and provide feedback loops. The next step should be asesssing best practices at the systems and components level along four intersecting building physical systems- Mechanical Systems for Heating, Ventilation and Air Conditioning , Plug Loads, Lighting and Envelope/Passive systems. The qualitative best practices described in this guide offer opportunities for building designers, owners, and operators to improve energy efficiency in commercial office buildings.
Although the practices are presented individually, they should not be thought of as an “a la carte” menu of options. Rather, building systems must be integrated to realize the maximum energy and cost benefits. Also, designers and engineers, and developers and tenants need to work together to capitalize on the synergies between systems. Last but not the least, this guide provides tangible quantitative best performance metrics, ready to be adopted by buildings in India. These metrics are concrete targets for stakeholder groups to work together and enable, by providing localized and customized solutions for each building, class, and occupants. Having targets early on in the design process also translates to more-efficient design lead times. The potential benefits of adopting these metrics include efficient operations, first-cost and life cycle cost efficiencies, and occupant comfort and well-being. The best practice strategies, if used thoughtfully provide an approach towards enabling office buildings that would deliver throughout their entire life cycle, a flexible optimization of energy consumption, productivity, safety, comfort and healthfulness. The adoption of the qualitative and quantitative goals, would provide an impetus to scale up and market transformation toward energy-efficient processes, resources, and products- in addition to generating positive outcomes on global warming and societal benefits.Buildings in India were traditionally built with high thermal mass and used natural ventilation as their principal ventilation and cooling strategy. However, contemporary office buildings are energy-intensive, increasingly being designed as aluminum and glass mid- to high- rise towers . Their construction uses resource-intensive materials, and their processes and operations require a high level of fossil fuel use. A large share of existing and upcoming Indian office space caters to high-density of occupancy and multiple shift operations. Whereas the average for U.S. government offices is 20 m2 /occupant and for US private sector offices is 30 m2 /occupant, Indian offices have a typical density of 5–10 m2 /occupant. Business Processing Office spaces have three-shift hot seats—a situation that while conserving space because of its multiple usage also leads to considerably higher EPI levels.
Moreover, with the increased demand for commercial office spaces from multinationals and IT hubs, and the current privileges being accorded to Special Economic Zones , the trend is toward larger buildings with international standards of conditioned spaces, dramatically increasing the energy footprint of Indian offices .Building energy consumption in India has seen an increase from 14% of total energy consumption in the 1970s to nearly 33% in 2004-2005. The gross built-up area added to commercial and residential spaces was about 40.8 million square meters in 2004-05,flood and drain table which is about 1% of annual average constructed floor area around the world and the trends show a sustained growth of 10% over the coming years, highlighting the pace at which the energy demand in the building sector is expected to rise in India. In 2004– 2005, the total commercial stock floor space was ~516 million m2 and the average EPI across the entire commercial building stock was ~61 kWh/m2 /year. Compare this to just five years later in 2010, when the total commercial stock floor space was ~660 million m2 and the average EPI across the entire commercial building stock almost tripled to 202 kWh/m2 /year . Energy use in the commercial sector is indeed exploding, not just due to the burgeoning of the Indian commercial sector- India is expected to triple its building stock by 2030 , but also through the increase in service-level requirements and intensity of energy use. Thus there are two intertwined effects: an increase in total building area and an increase in the EPI. According to India’s Bureau of Energy Efficiency , electricity consumption in the commercial sector is rising at double the rate of the average electricity growth rate of 5%–6% in the economy. To deliver a sustained rate of 8% to 9% through 2031-32 and to meet life time energy needs of all citizens, India would need to increase its primary energy supply by 3 to 4 times and electricity generation capacity about 6 times.According to UNEP, approximately 80%–90% of the energy a building uses during its entire life cycle is consumed for heating, cooling, lighting, and other appliances. The remaining 10%–20% is consumed during the construction, material manufacturing, and demolition phases. To manage and conserve the nation’s energy, it is imperative to aggressively manage building energy efficiency in each commercial building being designed and operated in India. By increasing energy efficiency in buildings and other sectors such as agriculture, transportation, and appliances, it is estimated that the total Indian power demand can be reduced by as much as 25% by 2030.
To this end, the best practices outlined below identify processes and strategies to boost the energy efficiency in buildings, while also focusing on cost efficiency and occupant comfort.Just as no two buildings are identical, no two owners will undertake the same energy management program. It is also improbable to include all the listed best practices into one building, since some of them will conflict with each other. The practices are presented individually; however, they should not be thought of as an “a la carte” menu of options. Rather, designers and engineers, developers, and tenants need to work together to capitalize on the synergies between systems . From the demand side, this means implementing a suite of measures that reduce internal loads as well as external heat gains . Once the demand load is reduced, improve systems efficiency. Finally, improve plant design. This is illustrated through the Best Practice strategies and Data Points in this guide. The supply side can then add value by provision of renewables, waste heat sources, and other measures that are beyond this guide’s scope .A whole-building system integration throughout the building’s design, construction, and operation can potentially assure high performance, both in terms of energy efficiency and comfort/service levels.This Lifecycle Performance Assurance Framework was conceptualized by Lawrence Berkeley National Laboratory, USA and the Center for Environmental Planning and Technology, India through U.S. and Indian stakeholder engagements during the U.S.-India Joint Center for Building Energy Research and Development proposal to the U.S. Department of Energy and Government of India, 2011. At each stage of the life cycle, it is critical to ensure integration between the buildings’ physical systems and the building information technologies. The building physical systems include Envelope, HVAC, Plugs, Lighting and Comfort technology systems . Whereas, building information technologies provide information on the design and functioning of the building physical systems. First, by performing building energy simulation and modeling at the design phase one can estimate the building’s energy performance and code compliance. This is especially relevant for certain energy conservation measures that may not be immediately attractive, but may become so through further analysis. Second, by building in controls and sensors for communications, one can track real-time performance at the building phase, relative to the original design intent. Third, by conducting monitoring-based commissioning and bench marking during operations, one can ascertain building performance, compare to peer buildings and provide feedback loops. Thus the use of building IT creates metrics at all three stages of the life cycle to help predict, commission, and measure the building performance and its systems and components. .To design and operate an energy-efficient building, focus on the energy performance based on modeled or monitored data, analyze what end uses are causing the largest consumption/waste, and apply a whole-building process to tackle the waste. For instance, peak demand in high-end commercial buildings is typically dominated by energy for air conditioning. However, for IT operations, the consumption pattern is different. In the latter, cooling and equipment plug loads are almost equally dominant loads. The equipment plug load is mostly comprised of uninterrupted power supply load from IT services and computers, and a smaller load is from raw power for elevators and miscellaneous equipment. Figure 8 shows typical energy consumption end-use pies — energy conservation measures need to specifically target these end uses. By doing so, one can tap into a huge potential for financial savings through strategic energy management. However, a utility bill does not provide enough information to mine this potential: metering and monitoring at an end-use level is necessary to understand and interpret the data at the necessary level of granularity. Energy represents 30% of operating expenses in a typical office building; this is the single largest and most manageable operating expense in offices. As a data point, in the United States, a 30% reduction in energy consumption can lower operating costs by $25,000 per year for every 5,000 square meters8 of office space. Another study of a national sample of US buildings has revealed that buildings with a “green rating” command on an average 3% higher rent and 16% higher selling price.