ECOFRIENDLY HOME SOURABHA
Bangalore's First
Eco-friendly house to depend only on Rainwater Harvesting since 1994 - "Sourabha"
Rainwater Harvesting can be
defined as the process of collecting and storing rainwater in a scientific
and controlled manner for future use.
Rainwater Harvesting
Water is one of the most common substances on our earth. But urban areas
face a shortage of water and require an alternative source to bridge the
gap between demand and supply. Rainwater would be an immediate resource to
augment the existing water supply systems by "Catching water wherever it
falls"
.
Sourabha is located in
southwestern part of Bangalore (Vijayanagar). Plot area is 2400 Sq. ft.
(40 ft. x 60 ft.). House constructed during 1995. This house is entirely
dependent on rainwater for all its need since 1994 (including
construction).
Rainwater falling inside the
plot is being channeled to three applications.
1. Roof top rainwater
harvesting
2. Roof top rainwater
channeled to recharge ground water
3. Percolation in garden
area to recharge ground water.
Majority of the rainwater
falling on the roof (85%) is channeled to the northern side of the house
and is allowed flow in to a tank of 4500 lts. capacity built on the ground
floor roof. PopUp filter along with a stabilization tank specially
designed will filter the roof water before storing. This water is used
during the rainy season. The over flow of this tank is allowed to rundown
through rainwater pipe on the wall to an under ground sump-1 of 25,000 lt
capacity built under the portico at the entrance of the house. In the
event of these two tanks getting full, the rainwater is diverted to
percolate into the ground through a system of percolation tanks /
infiltration gallery (4 recycled plastic drums interconnected and buried
underground with their bottom cut open) to recharge ground water.
The remaining portion of the
roof water (15%) is allowed to rundown through rainwater pipe on the wall
and a PopUp filter installed at the ground level filters suspended and
floating material. Relatively cleaner water after filtration flows to an
underground sump-2 of 10,000 lt Capacity built inside the car park
(garage). Sump-1 and sump-2 together with 35,000 lt capacity are
interconnected and the stored rainwater water is used during the non rainy
days when the roof top tank water is not available.
Rainwater falling in the
open area or the garden area around the house is allowed to percolate then
and there in to the ground to recharge ground water.
In this manner not a drop of
rainwater falling in the plot is allowed to flow out.
Bangalore receives around
1000 mm of rainfall in a year. Which translates in to around 2,23,000 lts
per year cumulatively in a plot of 60 ft. x 40 ft. Bangalore has an
advantage of having nearly 70 rainy days spread throughout the year.
There is no Corporation or
BWSSB water connection to this house. Clean and safe water is available 24
hours 365 days a year and the quality of water is also periodically tested
and found to be good.
"Sourabha" house has inbuilt
simple mechanisms to effectively harness all the rainwater falling in the
plot and channel the same for different purposes. Even before constructing
the house, rainwater harvesting was the answer for the water requirement.
The house was constructed by using the harvested rainwater. Since 1995 the
entire house needs including potable water is met out of rainwater. As a
family of four we need around 15,000 lts of water per month.
We require around 400 lt per
day for all our needs except for toilet flushing. The need of toilet
flushing is met by recirculation of used water from washing machine. Used
water from washing machine is stored in an underground tank and is pumped
up to a tank on the roof for toilet flushing automatically.
During days with more than
100 days of continues no rainy days which is very rare in Bangalore, water
drawn from a shallow tube well, which gets recharged from rainwater, meets
the requirement. Ground water table in and around the plot before the
rainwater harvesting was as deep as 200 ft. (Sourabha is located on the
top most position of a ridge). With in one year of ground water recharge,
water is available at around 40 ft. In Sourabha the amount of water used
is far less than the amount of rainwater harvested and ground water
recharged. Consequent to this, a social cause to recharge the
ever-dwindling ground water is also attempted.
There is no recurring cost
involved except for the electricity used for pumping up water. The
electricity consumption in Sourabha is around 80kWh (units) per month,
which includes water pumping also. Low electricity consumption in the
house is due to several energy conservation methods and renewable energy
techniques adopted in the house.
"SOURABHA"
1.
Building/project name
|
:
|
A. R.
Shivakumar's residence
|
2.
Site address
|
:
|
No.44,
Sourabha, 3rd Main, Basaveshwara Layout,
Vijayanagar, Bangalore - 560 040. |
3.
Building Type
|
:
|
Residential
|
4.
Architect
|
:
|
Sudha
and Jayashree
|
5.
Energy Efficiency planning
|
:
|
A. R.
Shivakumar
|
6.
Year of completion
|
:
|
November
1995
|
7.
Owner
|
:
|
A. R.
Shivakumar
|
8.
Building description.
Site area 40 feet x 60 feet, facing south, land slope varying from
0 at road side to +7 feet at the northern tip. Total built up area
2200 sq. ft. three bedrooms, four toilets, kitchen, living room,
dining hall, drawing room, garage for two four wheelers and sit-out.
Garden area including terrace garden of 900-sq. ft. and three trees.
Four water bodies with fishes and aquatic plants (lotus, etc.)
|
9.
Energy saving on solar passive features.
Rattrap design for most of the exterior walls, Most of the living
area not directly exposed to southern and western sun. Large windows
opening towards east, north and south. South and west facing windows
with sun-control glass. Roof claded with clay tiles or painted bright
white. Living room with roof height of 18 feet and provides ventilation
and sky lighting in the roof.
|
10.
Installed renewable energy systems and waste management techniques
|
11. Incremental costs
(year 1995): |
(Rs.)
|
|
a)
|
Integrated
solar water heater 200 lpd at 60oC with rice husk insulation |
7505.00
|
|
b)
|
Integrated
solar cooker
|
480.00
|
|
c)
|
Rain
water harvesting with direct storage of 10000 lts. (popup filter,
underground sump)
|
16250.00
|
|
d)
|
Groundwater recharge
(shallow bore well, charged by soak pits of re-used oil barrels and
open garden) |
2600.00
|
|
e)
|
Vermicompost
to treat all domestic solid waste
|
165.00
|
|
f)
|
Solar
lighting, 11 watt cfls, 4 No. for 4 hours per day with 35 watt peak
2 PV panels
|
18000.00
|
|
g)
|
Compact
fluorescent lamps,3w-8, 7w-2, 9w-3, 11w-8, 13w-2, and 15w-2
|
7400.00
|
|
h)
|
Fluorescent
tube light with electronic ballast, 40w-4 and 20w-4
|
3200.00
|
|
i)
|
HDPE
pipes and high efficiency water pump
|
14750.00
|
|
j)
|
Drip
and sprinkler irrigation
|
320.00
|
|
k)
|
Refrigerator
modified to open on the right side to save energy
|
250.00
|
12.
Performance results since November 1995 till day
|
|
a)
|
Average
electricity consumption of around 80kWh per month
|
|
b)
|
No
water connection or supply from city corporation supply or private
supply, living entirely on rainwater
|
|
c)
|
One
bedroom is cooler by 3oC to 4oC compared with other buildings during
summer
|
|
d)
|
Not
used corporation dust bin to dispose domestic waste (degradable
for vermicompost, metals and plastics for recycling)
|
|
e) |
Not purchased either
organic or in-organic manure for hundreds of plants, used only vermicompost
manure |
|
f) |
Domestic LPG consumption
of one cylinder (14 kg) for around 90 days |
|
g) |
No chemical pesticides
used, only neem based pesticides, which is generated from the neem
tree grown inside the plot. |
List
of few techniques used in the construction of the house for cost
reduction, energy conservation and environmental protection
|
|
*
|
Use
of the natural land topography to avoid excessive excavation or
filling
|
|
*
|
Design
of the foundation with split-levels
|
|
*
|
Use
of rat-trap design in wall construction (good thermal insulation,
saves bricks, cement and time)
|
|
*
|
Exposed
brick or stonewalls to avoid plastering and painting
|
|
*
|
Provide
rain water pipes to facilitate ground water recharging and direct
water harvesting for use during non rainy days
|
|
*
|
House
plan with all the water usage points like bath rooms, toilets, kitchen
and utility to come as close as possible to a open duct which carry
all the pipes
|
|
*
|
Provision
of windows to get as much sun light and cross ventilation as possible
|
|
*
|
Provide
glass windows in the roof for more light
|
|
*
|
Design
of at least one bedroom to have natural air conditioning (rat-trap
design walls, no wall to get direct sunlight, windows to face green
garden and in the direction of wind flow, roof to be paved with
clay tiles or painted white)
|
|
*
|
Solar
water heater and solar cooker built as an integral part of the house
|
|
*
|
Solar
lighting using PV panels
|
|
*
|
Use
of energy saving devises like, CFLs, HDPE pipe, high efficiency
motor and pump, light colors for interiors, sun control film on
glasses of south and west facing windows, drip/sprinkle irrigation
for plants, light sensitive switches for security, electronic regulators
for fans, toilet flush with adjustable discharge, refrigerator with
right side opening door, use of task lighting methods
|
|
*
|
Vermicompost
for handling organic waste
|
|
*
|
Provision
to plant as many plants and trees as possible (including terrace)
|
|