ECO-HOMESInnovative ways to Air-Conditioning

Team Name - Dream Green Immaculate 2013,Event- Eco-Homes

B H Gardi College-Rajkot

Presented at:

What is ECO-HOME ?

Building in a way that is environmentally, socially,

economically, functionally and aesthetically

balanced to meet today’s need and to conserve

resources for future generation.

Features of ECO-HOME

Green/Recycled Building Materials. Energy- Efficient Design. Alternative Energy. Water and Waste Management. Indoor environmental quality enhancement. Cost and payback (Operational Savings).

Fly-Ash Bricks Attics

Orientation Pergolas.

Some Common Components

Why Focus on Air-Conditioning?

• Air Conditioning or Heating of building consumes highest 57 % of total energy.

• May vary from place to place and building to building.

• With the increasing of standard of living more and more conditioning systems are installed. Thus demand is increasing exponentially.

• If the initial design considers energy efficiency measures in these areas, substantial energy savings can be realized.

There are two ways of reducing the temperature:

• Direct Cooling, where the air is passed over a cold object such as the cooling coil of an air conditioner or pre-cooled stonework, its energy is actually absorbed by the object. So the cooling is done without adding any moisture.

• Evaporative Cooling, where the air makes intimate contact with a flowing stream of water, either in a wet pad or a spray. Here, while the temperature comes down, its total energy content remains the same, as the latent heat of water vapour is added. Thus while this air will cool a warm object such as a human body or some stonework, it will not reduce the air conditioning load.

Theory of Air Conditioning

Heat exchange takes place

Direct cooling Evaporative cooling

Some Ancient Practices:

In India, our massive heritage buildings remain cool and comfortable because they absorb solar heat during the day.

Our ancestors had used mass and moisture innovatively to provide thermally comfortable built environments throughout the long and hot Indian summers while using little or no energy.

Properly designed, the system works very well as can be felt during a visit to the Gol Gumbaz and the Taj Mahal that remain cool throughout the summers.

Gol Gumbaz, having 10-feet thick walls and measuring 100 feet square topped by a massive dome, depends on its enormous mass to absorb the solar load, while maintaining the 18,000 odd square feet of its interior quite cool.

Heritage Structures-Remains cool by the virtue of

their mass.

GOL GUMBAZ

TAJ MAHAL

HAWA - MAHAL• The Hawa Mahal of Jaipur typifies the

technique that is repeated in many other heritage buildings.

• Air is made to pass through fine grillwork carved in thick stone walls that are cooled by water passing through channels built into them during construction.

• Water and air passages are sealed from one another. Thus, the stones cool the air sensibly by contact and energy is actually removed from the air.

COOLING TOWER Incorporating Hawa Mahal in Modern

Time

• Cooling tower (Sheetal Minar) uses both evaporative cooling as well as direct cooling in sequence.

• First it cools the stones evaporatively at night and dries them using the dry and cool air at dawn.

• The cold stones then directly cool the hot outside air during the daytime. This reduces the cooling load of the fresh air using natural processes only.

Design

The tower is divided into three parts. 1. The top portion is a spray chamber with air inlets on all

four sides. A pipe header has nozzles that spray water evenly into the next section.

2. The second section is stuffed with stones or cement blocks arranged so that the air and water pass through easily.

3. The bottom portion contains the two air outlets, a fan, dampers and a pump that is submerged in the water.

Operation: At night, the cool dry air is drawn in at the top and is further cooled by evaporation. The air and water cool the stone mass. Saturated air is exhausted out; the water drops into the basin for recirculation.During the day, the pump is off, and about 100 tons of cool stones remove about 100 ton-hours of heat from 4000 cfm of hot air going to the AHU, thus saving huge energy by reducing the cooling load.

Godrej Green Business Center, Hyderabad

MODERN TECHNIQUE

Case study on Torrent Research Center

Ahmedabad

• http://www.ishrae.in/journals_20042005/2004apr/article03.html

Passive Downdraft Evaporative System

• http://www.ishrae.in/journals_20042005/2004apr/article03.htmlPassive Downdraft Evaporative System(PDES)

19400 meter-sq of area is cooled by this system

Mist water cooled by night sky and stored in insulation tank

Hoppers installed for moment of air Dealing with three different intakes 1] hot and dry air in summer 2] cool and dry air in winter 3] humid air in monsoon.

Source - http://www.mcdberl.com

Intake of air.Mixing mist with air.

Cool air moving down due to thermal difference

Cool air distributed by hopper windows

Cool air used and rising of warm air to ventilator

Air released

Features

• http://www.ishrae.in/journals_20042005/2004apr/article03.html• Each building comprises of 70-80 people.• Temperature maintained inside the building is 12-14 degrees less then external

peak.• Temperature fluctuation is less then 4 degrees in 24 hours.• By survey of people in building the comfortable levels are rated above average.

• Result for summers are less consistent when compared to air-conditioned building but yet they were consistent as per world standards.

• By PDEC at TRC, 26 degrees could be maintained in summer.

Analysis and Prospectus

Studies prove that this system’s are efficient and truly are modernized versions of our ancient technology, they can be incorporated with present buildings.

By this you can save

Earth For coming generations

Preferred Additional Measures

• Making Tower using recyclable or recycled materials like Fly-ash, Slag etc.

• Proper orientation of building and wind tower.

• Incorporating other alternatives along with cooling towers: Geo-Thermal pump,

• Using energy efficient air-conditioners.

• The 60 per cent of the roof of the building is covered by the roof garden as a good insulating property and to cut down the load on the air-conditioning system.

Conclusion

Our ancestors did not have the technologies of RCC, welding, air moving, pumping or thermodynamics except perhaps in rudiments. Of course, they did not have electricity. By infusing these into their technique of structure cooling, sufficient savings have been achieved to keep AC&R affordable and sustainable. May it be universally adopted.

References:

• http://www.ishrae.in/journals_20042005/2004apr/article03.html• http://

www.mcdberl.com/tech/Passive_Down_draft_evaporative_cooling.pdf• http://en.wikipedia.org/wiki/Hawa_Mahal• http://www.archidev.org/IMG/pdf/Post_Occupancy_Evaluation_of_TRC-_

Paper_by_Thomas_Baird.pdf• http://www.solaripedia.com/13/94/814/godrej_green_business_center_

wind_tower_(india).html

• http://www.elliot-glassman.com/index.php?/projects/phoenix-school/

Thank You GO GREEN ! DREAM

GREEN !

A penny saved is a penny earned, they said. So with joules of energy!