earth air ventilation system
DESCRIPTION
Air Conditions are very energy intensive to run, so the buildings at TERI University, India are cooled through a new air ventilation system.TRANSCRIPT
15 July 2010
TERI University – Green and
Sustainable
Setu Goyal, Sandeep Goel
Students, M.Tech. (Renewable Energy)
TERI University is a premier University in India, focussing largely on post-graduation
education and covering a multitude of inter-disciplinary courses based on energy and
environment. We feel highly honoured to be a part of such an institution that provides its
students and faculty with world-class facilities ushering in innovativeness and multi-
disciplinary research. True to its mission, the University houses a variety of sustainable
measures at its New Delhi campus, which not only make it a ‘green’ building, but also bring
in a sense of responsibility and concern for the environment, within each and every individual
who call themselves to be a part of this wonderful institution of knowledge and learning.
Introduction:
One of the many successful sustainable measures employed at our campus is the Earth Air
Tunnel Ventilation System. It is utilized to meet the thermal requirements of the building, by
making use of the heat sink property of earth. The air that passes onto the buried pipes gets
cooled in summers and heated in winters, maintaining a comfortable ambience inside the
premise thorough out the year. Complimentary conventional measures of heating and cooling
are only considered based on the severity of the climate, resulting in a saving of almost 50%
of electrical power consumption in the building.
The system takes in air from the inlet above ground at the end of a long tunnel system
reaching almost 4 meters beneath the ground, with the help of an Air Handling Unit. The air is
then de-humidified and passed into the load area, thorough the conventional system of ducts
and diffusers, while the exhausts with the help of a wind operated exhaust turbine are sent out
through a chimney.
Concept:
The technology is based on the premise that earth acts as a great agent of heat sink, to the
extent that annual heat losses from earth are only 10 % of the total annual collected energy.
Also, it is an established fact, that for any given place, the diurnal variations in surface
temperature are ineffective at depths more than 0.5 meter beneath the ground and similarly the
seasonal variations fail to play a role at depths of about 4 meters beneath the ground levels.
As a consequence of the above, the air temperature at depths of 4 meters remains almost
equivalent to the annual average surface temperature of that particular place. This air if blown
to cater to the Heating Ventilation and Cooling (HVAC) requirements of a building, can
greatly minimize its energy consumptions, resulting in savings and a more sustainable and
environment friendly solution.
Although this technology has to be essentially incorporated within the building structure,
during its construction phase, another approach could be to couple the building with ground
using underground and partially underground structures. The latter approach is however less
efficient, however it is still more efficient than the conventional setup.
Advantages:
Most significant benefits are in terms of the saved energy requirements and emissions. With
the conventional centralized coal generated electric power, having minimal efficiencies (just
about 33%) and huge transmission and distribution losses and carbon emissions, the actual
energy demand and carbon footprint of buildings can sky-rocket if such energy efficient and
clean measures are not implied. At the same time, it also results in an improved indoor air
quality, by reduction in both fungal and bacterial load of the air and also by utilizing 100%
fresh air, instead of partly re-circulated as in the case of conventional HVAC systems.
Other Sustainable measures in place:
Earth and Space conditioning
Apart from the above mentioned feature, two more measures are in place, to minimize the
energy requirements towards building’s heating and cooling needs. One is the Variable
Refrigerant Volume System, in place to cater to areas with partial load conditions and varying
occupancies. Other is the Thermal Mass Storage which involves the storing of thermal energy
when it is available and utilization when required.
Water
Various measures have been taken by the University to contribute its bit towards saving this
precious natural resource, right from the selection of toilet fixtures in terms of dual flush
toilets and sensor taps, to extensive rain-water harvesting to recharge and improve the quality
of ground water. An effluent treatment plant too has been setup to treat the waste generated
from students’ hostel and canteen area. The waste water is utilized to water the gardens and
for landscaping purposes.
Sun
The building has been predominantly given a North-South orientation to avoid the glaring day
light. It has been provided with minimum windows on its East-West and South facades while
the South-West openings have been provided with shading devices. The university also
utilizes the solar energy to cater to its warm water requirements, by the use of solar water
heaters.
Sky
Various energy saving measures are in place, which have resulted in the reduction of lighting
load from 2 W/sqft to 1W/sqft. These include fixtures with continuous dimming electronic
ballast where daylight is available and occupancy sensors in areas of non-uniform
illumination. Use of double glazing windows, insulation in roof slabs and insulated stone-clad
walls have further resulted in great energy savings.
Student Initiatives
Aahvaan’10
The University also encourages the students to actively involve in extra-curricular activities.
Aahvan’10 is our annual inter-college, national level cultural event, which houses numerous
events and competitions promoting the spirit of participation and cultural unanimity among
the students. This year’s event is being promoted as a ‘green’ and carbon neutral event, an
initiative, taken care of entirely by the students of the university.
Cups
In their bid to contribute to the environment, the students and teachers at the university have
vowed not to use plastic bags/paper cups within the building premise. Most of the individuals
carry ceramic mugs and jute bags to serve their purposes.
Various workshops/seminars/movie projections
Students are persistently involved in organizing environment-oriented workshops, seminars
and movie screenings in order to inculcate and foster among the fellow mates, a sense of
responsibility towards the planet.
Student initiatives in progress
Campus sustainability
The university has its own Campus Sustainability Club (CSC) formed by a bunch of
enthusiastic individuals, persistently seeking way to reduce the University carbon footprint.
One of the ongoing projects of CSC is to formulate a solar PV based power generation system
for the University. In this regard, the University footprint has already been measured, the past
years electricity bills reviewed and the block-wise load requirements assessed. It is in the final
stages for the technical and economic feasibility assessment for the implementation of such an
idea.
Reva car charging station
Yet another feather in CSC’s cap. The university owns a 4-seater electric car, for which a
solar charging station has been proposed. A proposal is being prepared for a demonstration
level model to be approved by the Ministry of New and Renewable Energy in India. If
implemented, the station would be first of its kind in the country.
Paper recycling
The university generates nearly 200 kg of paper waste each month. This is currently being
sold to a local vendor. A proposal is in the offing from the CSC volunteers, to research on the
economic viability of buying a self-reliant paper recycling machine for the University. This
plan on implementation would save another hundred tonnes of CO2 emissions per annum.
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REVA Electric
Cars
Automatic Louvers for
shading
Rain water
harvesting Ground water reclamation
Inlets to Earth Air Tunnel
Earth Air
tunnel
Solar Hot water
Effluent treatment plant
Building layout