Buildings account for a large portion of energy consumption and greenhouse gas emissions worldwide. While vehicles have become more fuel efficient, buildings have not improved much in terms of energy efficiency. This document proposes several solutions to make IIT Delhi buildings more energy efficient, such as installing a building management system to automate lighting and cooling based on occupancy sensors, switching to more efficient LED bulbs, implementing daylighting design techniques, using a biomass gasifier for power, installing underground air tunnels for passive cooling, installing solar photovoltaic cells, and using energy efficient windows. These techniques could significantly reduce the campus' energy usage and costs while making the buildings more sustainable.

1. CSR310 Professional Practices
Assignment 1
Vikalp Kumar Singh(2010CS10264)
Sarvesh Sahota(2010CS10249)
Kangkan Boro(2010CS10221)
Somit Pangtey(2010CS10257)

2. Problem Definition:
Buildings are some of the biggest energy consumers in the world, accounting for one-quarter to one-
third of all energy use and a similar amount of greenhouse gas emissions. While cars have had to
meet increasingly strict fuel efficiency standards, buildings for the most part have gotten off easy.
Surprisingly little attention has been paid to ensuring energy efficiency in buildings, despite the
tremendous impact buildings have on costs and the environment.
That oversight is starting to be addressed. A combination of higher energy prices, skyrocketing
demand for electricity and deepening environmental concerns has pushed us to a tipping point with
regard to energy efficiency in buildings.
IITD also reflects the need of such buildings. Although many techniques have already been deployed
to cut off energy bills and make things “greener”, there is still a lot scope left. As the campus
buildings are expanding, being reconstructed, the idea of sustainable development comes into
picture. Although the greenest building is the building that doesn't get built, but that does not solve
the problem. So, there emerges a need of making our buildings more efficient using the technology
and techniques available.
Opportunities for Improvement and Proposed Solution:
Buildings like the Bharti Building, that are accessed 24/7, can be made energy efficient by the
Building Management System as proposed by Prof. Culler. An automated system which through the
use of a wide array of sensors spread across the building monitoring the presence of people, amount
of light entering through the windows and efficiency of the cooling units can be used to feed data to
automated system, this system can use this data to make energy efficient decisions regarding the
building. So the automated system would itself turn off/hibernate all computers when it sees that no
one is in the lab, and also shutting off the cooling system as well as the lights. If in summers a room
has reached the desired temperature and is not being used and is not scheduled to use for a while,
the system would automatically stop further cooling of the room, if it’s daytime and the light
entering through the windows is enough to brighten up the room, it will turn off the light bulbs and
use only the light entering through the windows and when it detects that this light is not enough it’ll
start turning on the bulbs. Unused corridors will light up only when someone is sensed using them
and turned off when no one is detected during the night. This automated system could be a part of
the larger automated system that monitors energy usage throughout the entire campus, and
redirect more energy to labs during the day and to hostels during nights, as hostels are usually
empty during the day and labs during the night.
Other than the automated system which makes smart decisions for the building, we can do better by
using devices that are themselves more energy efficient. A simple enough device to replace would
be the bulbs that we use. We can switch to more efficient lighting bulbs such as the LED bulbs. The
following table gives the comparison between the LED, CFL and incandescent bulbs

3. It’s pretty obvious that in the longer run LED bulbs provide a more efficient lighting solution.
Wiki defines Daylighting as the practice of placing windows or other openings and reflective surfaces
so that during the day natural light provides effective internal lighting. Particular attention is given to
daylighting while designing a building when the aim is to maximize visual comfort or to reduce
energy use. Energy savings can be achieved either from the reduced use of artificial (electric) lighting
or from passive solar heating or cooling. Artificial lighting energy use can be reduced by simply
installing fewer electric lights because daylight is present, or by dimming/switching electric lights
automatically in response to the presence of daylight, a process known as daylight harvesting. So
with new buildings coming up, we can design them in such a manner that we use natural light as
much as possible by using daylighting techniques.
Daylighting: Specially designed skylights, energy-efficient lights, and a sophisticated system of
monitoring and controlling the consumption of electricity illuminate the complex. The conference
rooms enjoy glare-free daylight through strategically placed skylights. A master control system
switches off the lights automatically whenever it senses that daylight alone is enough to maintain
the desired level of illumination. In the hostel rooms, strategically placed light points and specially
designed swivels make it possible to use the light at a study table as well as for bedside reading.
Biomass gasifier: Firewood, dried leaves and twigs, the stubble left in the fields, and such other
forms of biomass can fuel a 50-kilowatt gasifier, which will be the source of power for the buildings
during the day. The gasifier runs a generator, the diesel requirements of which have been cut down
to 30% after appropriate modifications; the rest of the fuel comes from the gasifier in the form of
‘producer gas’.
Subterranean air tunnels: Effective insulation, shade provided by trees, and a network of
underground earth air tunnels circulating cool subterranean air throughout the residential block

4. might ensure that the temperature in the complex remains more or less even all year round. The
system can be augmented by adding chillers for dehumidification and additional cooling during rainy
days.
Solar Lighting(Photovoltaic Cells): Use of solar energy is a very good alternative to conventional
sources of energy. Solar Photo-Voltaic (SPV) cells can be installed at the roofs of all the buildings of
the institute which can supply considerable amount of energy.
The daily average solar energy incident over India varies from 4 to 7 kWh/m2
with about 1500–2000
sunshine hours per year (depending upon location), which is far more than current total energy
consumption. [Source: Wikipedia]
Now let us take the lowest of these values to get a lower bound on the energy produced:
IIT has a land area of about 325 acres i.e. 1,315,000 sq. meters. Let us assume that IIT Delhi has
4kWh/m2
incident solar energy per day (the lower bound). Also, we assume that the solar cells have
an efficiency of only 10%. From that logic, even if we are able to install solar cells on 10,000 m2
of
area, we have a net energy production of 4000 KWh per day! This energy can easily be used for
lighting purposes in the campus, including lighting the lecture theatres. This value is just the lower
bound on the energy produced. We definitely can expect to get more than that. As far as cost issues
are concerned, the government can fund this project to conduct research on solar energy, which, if
successful (which we hope it would be), could potentially be used for the whole country.
Energy Efficient Windows: Windows are an important element in passive solar design, which uses
solar energy at the site to provide heating, cooling, and lighting for a house. Passive solar design
strategies vary by building location and regional climate, but the basic window guidelines remain the
same—select, orient, and size glass to maximize solar heat gain in winter and minimize it in summer.
In heating-dominated climates, major glazing areas should generally face south to collect solar heat
during the winter when the sun is low in the sky. In the summer, when the sun is high overhead,
shading devices prevent excessive heat gain.
To be effective, south-facing windows should have a solar heat gain coefficient (SHGC) of greater
than 0.6 to maximize solar heat gain during the winter, reduced conductive heat transfer, and a high
visible transmittance (VT) for good visible light transfer. Windows on east-, west-, and north-facing
walls should be minimized while still allowing for adequate daylight. It is difficult to control heat and
light through east- and west-facing windows when the sun is low in the sky, and these windows
should have a low SHGC and/or be shaded. North-facing windows collect little solar heat, so they are
used only for lighting. Low emissivity window glazing can help control solar heat gain and loss in
heating climates. [Source: http://energy.gov/energysaver/articles]
References:
1. http://eartheasy.com/live_led_bulbs_comparison.html
2. “Building Energy Efficiency: Why Green Buildings are key to Asia’s Future”, 2007, Wen H.,
Medalaine C., Ruth A. Shapiro, Mark L. Clifford, Hong Kong.
3. http://www.teriin.org/index.php?option=com_content&task=view&id=45

5. 4. http://www.uniblogger.com/en/Solar_Power_in_India
5. http://energy.gov/enerysaver/articles/energy-efficient-windows