Components of a Rainwater Harvesting System
A rainwater collection and storage system is comprised of many components. To produce good quality water all of the components need to be considered together.
Rainwater collection systems can be roughly separated into two types - those where the water runs by gravity to the cistern and those where the water runs by gravity to a surge/pump tank and is then pumped to the cistern.
A gravity flow to the cistern (shown at right) is ideal as it requires no power. Gravity flow to a surge tank and pumping to the cistern is a viable alternative where there is dependable hydro service or a back up battery/generator powered energy system.
The Roof
The key to choosing building materials for all parts of a rainwater harvesting system is to select materials that are non toxic and inert (non leaching.) This is particularly true of the roof that is subject to the oxidizing affects of sun and air borne pollutants. Avoid such contamination sources as lead flashings around sky lights or plumbing vents.
metal roof
torch on membrane
Water quality from different roof catchments is a function of the type of roof material, climate conditions, and surrounding environment. When choosing a roofing material - the smoother the better. The quantity of rainwater that can be collected is also a function of roof texture.
The most common type of roofing material used for rain catchment in British Columbia is galvanized metal that has been painted or enameled with a non-toxic material. Other materials include slate, terracotta tiles or concrete. Asphalt shingles are adequate but produce less water in summer and are harder to keep clean. Beware of the "modern" shingles that contain moss inhibitors if you plan to drink or bathe in the water.
Water collected from cedar roofs is acidic for plants and is impractical for indoor use.
metal roof with snow guard
metal roof with snow guard
asphalt roof
Gutters
Gutters should be made of inert materials. The most common gutters are continuous, baked aluminum gutters made and installed on site. Half-round vinyl is also excellent.
"Hidden gutters" are easy to clean.
When installing gutters make sure that there is a continuous slope towards the downspouts, and that there is no impediment to slow the flow of debris into the downspouts. Areas where the water can pool collect insects, organic materials and bacteria. Think of a gutter as a river - not a wetlands or swamp.
Gutter Guard
The decision to use gutter guard depends on the landscape and the number and type of shedding trees in the area. It keeps some debris out, but it also protects the debris that collects in the gutter, from the sanitizing and self cleaning of sun and wind.
In the Gulf Islands gutter guard is sometimes applied in the spring and fall to protect against arbutus berries, leaves and fir needlesl. The Rainwater Connection has done extensive research on different types of gutter guard and provides several choices.
Click for more information on Gutter Guards.
Downspouts
Anything from chains to traditional aluminum downspouts can be used to get the water down from the gutters
Sealed PVC piping is often used close to the ground, and where the water needs to be transported horizontally. This piping must be sized for good flows, storm events, and easy cleaning.
Click for more information on Downspouts.
Debris Traps
The Rainwater Connection believes that a series of debris traps and filters and necessary to clean the water as much as possible before it enters storage. For agricultural water a small leaf trap and cleanable pipe systems to catch the larger heavier debris may be all that is required.
Simple Catchement piping photo on
photo CD
For potable water systems a series of leaf and debris traps are used as the first step - leaf traps to capture the leaves, needles and berries, and pipe "pigtails" collect the heavier black debris.
The Rainwater Collection has developed several types of debris traps that work well in local conditions.
The Rainwater Connection also uses some of the German and Australian equipment.
Click for more information on Debris Traps.
Final Sediment Filtration
For potable water systems the water is usually passed through some form of fine mesh screen filter as a final cleaning before entering the storage tank or cistern. These filters would clog up too fast if used on their own, but as part of a system they can significantly improve water quality and reduce cistern cleaning.
Gravity mesh screen versions are used in gravity systems, and can remove suspended particles as small as 150 microns. Even finer filtration can be achieved in a pumped system.
First Flush Diverter
The first flush diverter routes the first flow of water from the catchment surface away from the storage tank. It is designed to fill with contaminated water from a rain event and empty itself over a 24 hour period so that it is ready for the next time it rains This system is used in most parts of the world to improve water quality for potable water systems.
flow past first flush diverter box with
valved dripper
first flush diverter pipe, buried in
ground
First flush diverters ("FFD'S") have been shown to remove up to 80% of the pollutants that collect on the roof or in the gutters and become dissolved or suspended in the water. For example, it removes much of the discolouration and acidity from contact with cedar, arbutus and fir needle debris.
The amount of water to reject depends on a variety of factors including:
Roof and gutter slope Roof material smoothness Rain intensity Preceding dry period Airborne pollutants (dust, smoke, auto exhaust) Tree debris
burried first flush diverter pipe
burried first flush diverter pipe at
completion
The rainwater Connection recommends rejecting at least the first 0.02 inch (0.5mm) of rain. This amounts to 10.4 imp gal per 1,000 sq ft of catchment area or 50 litres per 100m2. In extreme cases this is increased to as much as the first 0.04 or 1/25th inch.
The Rainwater Connection custom designs first flush diverters to suit individual circumstances. Most are simple flow past boxes or sloped pipes. Some of the Australian versions are also used.
Surge/Pump Tank
Where it is not possible or desirable for the roof water to run by gravity to the cistern it is directed to a surge/pump tank and is pumped to the cistern. The tank sizing depends on the roof size, the pump size and the desired storage capacity if/when the power fails.
It can be as small as 100 gallons and use a small oil free submersible pump or it can be over 500 -1000 gallons and the water can be pumped by a remote jet pump.
oil free submersible pump
Catchment System Example
A simple wall hung catchment system with downspouts to all-in-one debris pails, down into the first flush diverter pipe (before backfill), and when the FFD pipe is full, through the gravity filter and into the 150 gal surge/pump tank. Note the surge tank overflow.
Click for more
Water Storage
Water storage is the heart of a rainwater system in the Mediterranean climate of the Gulf islands and Vancouver Island.
Storage cisterns take many forms. As part of a design process it is important to assess your particular needs and the site opportunities to decide on the best option.
The most common storage tanks are the above ground molded polyethylene tanks ranging in size from 300 to 3,000 gallons. These are the least expensive alternative, but offer relatively little protection from UV sunlight that can affect the quality of stored water.
Ensure good access for cleaning and avoid direct sunlight if possible.
Some polyethylene tanks can be partially buried to prevent sunlight penetration, or hidden under decks. Examples show below:
For larger applications, the Rainwater Connection supplies and installs steel polypropylene-lined cisterns 4,000-30,000 gallons that are made of culvert steel, structurally engineered, and easily transportable to most sites. The liner has a water potable rating. (NSF 61). These tanks can be partially buried, tucked away in the woods, or situated under decks.
Other storage options include in-ground concrete cisterns (shown below), and ponds.
20,000 Gallon Cistern under Deck
20,000 Gallon Cistern under Deck
Don't forget to consider winterizing measures and specialized fittings for emergency water exits that a pumper fire truck could hook up to.
Water Disinfection
Treatment of rainwater is often simpler than treating water from wells or surface streams. Rainwater for indoor use requires a filtration and disinfection system to remove such things as parasites, bacteria, and virus from bird droppings, as well as insects, and wind blown materials that are carried onto the roof. Toxins leached from the roofing system can include heavy metals, petroleum products, algae, moulds, and yeast. (Note that many of these problems are also found in well water).
A rainwater disinfection system can be as simple as particle filters and a UV light.
For added protection and water treatment a BioSand filter can be used. This type of passive sand filter uses very little water for its maintenance backflushing process.
Disinfection and treatment products can be found at www.watertiger.net.
Good Design & Maintenance is the Best Guarantee of Quality Water
Planning ahead and careful design of a rainwater harvesting system will improve water quality and save money in the long run - especially for new construction. The Rainwater Connection works closely with their clients to ensure a sensitive design that balances the need to:
Collect as much water as possible Ensure good quality water Facilitate long term maintenance Fit the aesthetic requirements of the client
Rainwater harvesting systems require monthly and seasonal cleaning schedules to optimize water quality. The Rainwater Connection offers Owner's Manuals, 1st year monitoring of system, and annual maintenance contracts. Ease of operation and maintenance is designed into every system.
Panen Air Hujan, Yuk!
oleh: Anissa Q. Aini
Jangan sia-siakan air hujan yang turun ke Bumi. Air ini bisa dimanfaatkan untuk
berbagai keperluan.
Rain harvesting atau panen air hujan sebenarnya sudah ada sejak lama, tapi mungkin belum
banyak yang tahu. Apa, sih , panen air hujan itu? Sederhananya, panen air hujan adalah
menampung air hujan yang turun, untuk dimanfaatkan lagi. Misalnya, untuk menyiram tanaman,
mencuci kendaraan, mengepel lantai, atau menyiram toilet.
Tidak usah memikirkan cara yang rumit, kita pakai cara yang sederhana saja. Siapkan wadah
penampungan. Bisa membuat bak, seperti bak mandi atau drum plastik. Tempatkan di bawah
talang air, untuk menampung air hujan yang mengalir dari atap. Seberapa besar bak atau drum
yang harus ditempatkan? Sesuaikan saja dengan kebutuhan dan selera.
Untuk menyaring air hujan, tempatkan jaring kawat atau kain kasa, di permukaan bak atau drum.
Kemudian taburkan batu-batu koral di atas jaringnya. Batu koral berperan sebagai penyaring air
hujan, sebelum ditampung. Kalau Anda punya budget lebih, bisa membuat filter serupa filter air
kolam. Jadi air hujan bisa tersaring lebih baik. Dengan demikian, air hujan siap untuk digunakan.
Supaya mudah untuk mengambil air dari wadah penampungan, buat saluran dengan pipa, dari
wadah ke luar. Lengkapi juga dengan keran. Sebaiknya, manfaatkan air hujan yang sudah
ditampung untuk keperluan-keperluan non konsumsi. Tidak disarankan memanfaatkannya untuk
air minum, karena diperlukan penelitian lebih lanjut apakah air hujan aman dikonsumsi atau
tidak. Satu lagi, jangan lupa juga untuk menutup rapat dan menguras wadah penampungan secara
teratur. Supaya tidak jadi sarang nyamuk demam berdarah
Nah , mumpung sekarang musim hujan. Kita panen air hujan, yuk ! Buat mencuci kendaraan atau
mengepel lantai, kita gak perlu ambil air PAM atau air tanah. Jadi, kita bisa menghemat
pengeluaran untuk air.
AtAU (OUTPUT LEBIH BAIK) NAMUN BIAYA MAHAL
(ALAT) Filter Penyaringan & Penjernihan Air Bersih / Sumur Bor / Tanah untuk Rumah Tangga
(Alat) Filter Penyaringan & Penjernihan Air sangat diperlukan untuk memenuhi kebutuhan
air bersih Rumah Tangga, terutama untuk yang tinggal di kawasan perkotaan.
Dengan Melihat besarnya peran dan fungsi air bersih dalam kehidupan
sehari-hari terutama di daerah perkotaan, KAMILA fresh water filter telah berhasil
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ilmiah dan mampu menyerap kotoran lebih banyak serta menghilangkan bau, warna, kuman,
besi, mangan, dll.
Apakah air tanah (sumur bor) Anda kurang bersih dan memiliki kadar besi yang tinggi?
Atau Anda memiliki masalah dengan air tanah (sumur bor) yang berwarna kuning?
Dengan banyaknya permasalahan mengenai air bersih terutama di
pusat-pusat kota dan kawasan industri, limbah industri biasanya merupakan penyebab utama
penurunan kualitas air bersih sehingga air baku dirumah Anda tidak dapat langsung digunakan
untuk keperluan sehari-hari karena tidak memenuhi standar air bersih. Masalah yang sering
sekali muncul adalah air Anda nampak jernih ketika keluar dari kran, namun setelah beberapa
saat akan nampak berwarna kuning, bahkan dalam jangka waktu lama akan membentuk endapan
kuning dan menempel didasar bak penampungan air, apakah hal itu terjadi pula pada Anda? Jika
demikian berarti air Anda mengandung besi (Fe). Besi dalam air berupa ion Fe2+ kemudian besi
di bak penampungan air tersebut berinteraksi dengan udara bebas sehingga teroksidasi menjadi
ion Fe3+ dan berwarna kuning. Besar kecilnya kandungan besi dirumah Anda dapat dilihat dari
intensitas warna kuning yang terbentuk.
Tingginya kadar besi selain berbahaya untuk kesehatan juga warna kuning yang terbentuk
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masalah air rumah Anda, oleh sebab itu alat ini didukung dengan media sbb:
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FERROLITE / MANGANESE, berfungsi untuk menghilangkan kandungan besi (Fe) pada air
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warna kuning pada air.
KARBON AKTIF, sangat effektif menjernihkan dan menyerap bau, rasa serta racun pada air.
SILICA, berfungsi untuk menjernihkan air.
Media-media ini akan bekerja menyaring dan menjernihkan air rumah Anda sampai pada tahap
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Proses pemasangan Alat Penyaring Air ini sangat sederhana, bisa diletakkan pada penampungan
air ataupun pada pompa airnya, seperti gambar dibawah ini.
Untuk Anda yang memiliki masalah pada air rumah tangga, kantor, pabrik, apapun keluhannya
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COMPONENTS OF A RAINWATER HARVESTING
SYSTEM
A rainwater harvesting system comprises components of
various stages - transporting rainwater through pipes or
drains, filtration, and storage in tanks for reuse or recharge.
The common components of a rainwater harvesting system
involved in these stages are illustrated here.
1. Catchments: The catchment of a water harvesting
system is the surface which directly receives the rainfall and
provides water to the system. It can be a paved area like a
terrace or courtyard of a building, or an unpaved area like a
lawn or open ground. A roof made of reinforced cement concrete (RCC), galvanised iron or
corrugated sheets can also be used for water harvesting.
Source: A water harvesting manual
for urban areas
2. Coarse mesh at the roof to prevent the passage
of debris
3. Gutters:
Channels all around the edge of a sloping roof to
collect and transport rainwater to the storage tank.
Gutters can be semi-circular or rectangular and could
be made using:
Locally available material such as plain galvanised iron sheet (20 to 22 gauge), folded to required shapes.
Semi-circular gutters of PVC material can be
readily prepared by cutting those pipes into two equal semi-circular channels.
Bamboo or betel trunks cut vertically in half.
The size of the gutter should be according to the flow during the highest intensity rain. It is
advisable to make them 10 to 15 per cent oversize.
Gutters need to be supported so they do not sag or fall off when loaded with water. The way
in which gutters are fixed depends on the construction of the house; it is possible to fix iron or
timber brackets into the walls, but for houses having wider eaves, some method of attachment to
the rafters is necessary.
4. Conduits
Conduits are pipelines or drains that carry rainwater from the catchment or rooftop area to the
harvesting system. Conduits can be of any material like polyvinyl chloride (PVC) or galvanized iron
(GI), materials that are commonly available.
The following table gives an idea about the diameter of pipe required for draining out
rainwater based on rainfall intensity and roof area:
Sizing of rainwater pipe for roof drainage
Diameter
Of pipe
(mm)
Average rate of rainfall in mm/h
50 75 100 125 150 200
50 13.4 8.9 6.6 5.3 4.4 3.3
65 24.1 16.0 12.0 9.6 8.0 6.0
75 40.8 27.0 20.4 16.3 13.6 10.2
Source: A water harvesting manual for urban areas
100 85.4 57.0 42.7 34.2 28.5 21.3
125 - - 80.5 64.3 53.5 40.0
150 - - - - 83.6 62.7
mm/ h - millimeters per hour; m - meters
Source: National Building Code
5. First-flushing
A first flush device is a valve that ensures that runoff from the first spell of rain is flushed out and
does not enter the system. This needs to be done since the first spell of rain carries a relatively
larger amount of pollutants from the air and catchment surface.
Source: A water harvesting manual for urban areas
6. Filter
The filter is used to remove suspended pollutants from rainwater collected over roof. A filter unit is
a chamber filled with filtering media such as fibre, coarse sand and gravel layers to remove debris
and dirt from water before it enters the storage tank or recharge structure. Charcoal can be added
for additional filtration.
(i) Charcoal water filter
A simple charcoal filter can be made in a drum or an earthen
pot. The filter is made of gravel, sand and charcoal, all of
which are easily available.
(ii) Sand filters
Sand filters have commonly available sand as filter media.
Sand filters are easy and inexpensive to construct. These
filters can be employed for treatment of water to effectively
remove turbidity (suspended particles like silt and clay), colour
and microorganisms.
Source: A water harvesting manual
for urban areas
In a simple sand filter that can be constructed
domestically, the top layer comprises coarse sand followed by
a 5-10 mm layer of gravel followed by another 5-25 cm layer
of gravel and
boulders.
(ii. a) Dewas
filters
Most residents in
Dewas, Madhya
Pradesh, have wells in their houses. Formerly, all that
those wells would do was extract groundwater. But
then, the district administration of Dewas initiated a
groundwater recharge scheme. The rooftop water
was collected and allowed to pass through a filter
system called the Dewas fillter, designed by Mohan
Rao , district collecter of Dewas, and engineers of the rural engineering services. The water thus
filtered is put into the service tubewell.
The filter consists of a polyvinyl chloride (PVC) pipe 140 mm in diameter and 1.2m long.
There are three chambers. The first purification chamber has pebbles varying between 2-6 mm, the
second chamber has slightly larger pebbles, between 6 and 12 mm and the third chamber has the
largest - 12-20 mm pebbles. There is a mesh at the outflow side through which clean water flows
out after passing through the three chambers. The cost of this filter unit is Rs 600.
Filter for large rooftops
When rainwater is harvested in a large rooftop area,
the filtering system should accommodate the excess
flow. A system is designed with three concentric
circular chambers in which the outer chamber is filled
with sand, the middle one with coarse aggregate and
the inner-most layer with pebbles.
This way the area of filtration is increased for
sand, in relation to coarse aggregate and
pebbles. Rainwater reaches the centre core
and is collected in the sump where it is treated
with few tablets of chlorine and is made ready
for consumption. This system was designed by
R Jeyakumar
(Source: Jeyakumar; Rain water Harvest Manual P-21)
Varun:
S Vishwanath, a Bangalore water harvesting expert, has developed a rainwater filter "VARUN".
According to him, from a decently clean roof 'VARUN' can handle a 50 mm per hour intensity
rainfall from a 50 square metre roof area. This means the product is relatively standardised. For
new house builders we therefore can recommend the number of downpipes they have to optimise
Source: A water harvesting manual for urban
areas
on and the number of filters they will need.
'VARUN' is made from a 90 litre High Density Poly Ethylene
(HDPE) drum. The lid is turned over and holes are puched in it. This is
the first sieve which keeps out large leaves, twigs etc. Rainwater
coming out of the lid sieve then passes through three layers of sponge
and a 150 mm thick layer of coarse sand. Presence of sponge makes
the cleaning process very easy. Remove the first layer of sponge and
soak /clean it in a bucket of water (which you then don't waste but use
it for plants). The sand needs no cleaning at all. The basic cost of the
filter is about Rs 2250/-
ii. b. Horizontal roughing filter and slow sand
filter
The introducton of horizontal roughing filter and slow
sand filter (HRF/SSF) to treat surface water has
made safe drinking water available in coastal pockets
of Orissa. The major components of this filter are
described below.
1) Filter channel : One square metre in cross-
section and eight m in length, laid across the tank
embankment, the filter channel consists of three
uniform compartments, the first packed with broken
bricks, the second with coarse sand, followed by fine sand in the third compartment. The HRF
usually consists of filter material like gravel and coarse sand that successively decreases in size
from 25 mm to 4 mm. The bulk of solids in the incoming water is separated by this coarse filter
media or HRF. At every outlet and inlet point of the channel, fine graded mesh is implanted to
prevent entry of finer materials into the sump. The length of a channel varies according to the
nature of the site selected for the sump.
2) Sump: A storage provision to collect filtered water from the tank through the filter channel for
storage and collection.
While HRF acts as a physical filter and is applied to retain solid matter, SSF is primarily a
biological filter, used to kill microbes in the water. Both filter types are generally stable, making full
use of the natural purification process of harvested surface water and do not require any chemicals.
For more details:
Making Water Everybody's Business
iii. Rain PC
AcquaSure, a consortium of three specialist Netherlands-based
companies, has developed a system for the conversion of
rainwater to drinking water in the form of a Rainwater
Purification Centre (RainPC).
RainPC is developed by scaling down the multi-staged
water treatment method (MST), which involves screening,
flocculation sedimentation and filtration and incorporating
existing technologies like upward flow fine filtration, absorption
and ion exchange. Coming in a small compact 26 kg unit, the
RainPC offers an affordable solution by converting rainwater
into drinking water.
RainPC is made of ultra violet resistant poly-ethylene
housing and cover, stainless steel rods and bolts, a nickel-brass
valve and an adapter for maintaining constant volume. Xenotex-A and activated carbon catridges
along with ultra membrane filtration or micro-membrane filtration modules incorporated in the
RainPC has the capacity to deal with E-coli and the potential of meeting the Dutch as well as World
Health Organisations (WHO) water regulation standards. The components can also be transported
individually to be assembled at the site. Three product types are available based on their microbial
contaminant removal capacity. This technology is ideally suited for virtually any situation and is a
blessing particularly for those who have little or no access to regular safe drinking water.
The salient features of Rain PC are:
Simple straight-forward installation
Easy to operate and maintain
Needs no power and operates at low gravity pressure
(0.1 bar upward).
The system is capable of providing a constant flow of
about 40 liters of rainwater per hour, enough for a family of five for drinking, cooking and bathing purposes.
Maintains nearly constant volume irrespective of water
pressure.
The Xenotex-A and activated carbon cartridge processes up to 20,000 liters and can be regenerated up to 10 times.
Cost per 1000 litres is as low as US$ 2 to 3.
(The above information is as per the manufacturers' claims and not based on any study by
CSE.)
For further information Email: [email protected]
iv. Rainwater harvester
EA Water Pvt Ltd has launched a unique Rainwater Harvester, which filters runoff water from roads,
which generally contains oil and grease. This system has been installed in the Gymkhana club,
Sector-15, Faridabad, Haryana. Rajit Malohtra, project in charge, of this company explained that
the water harvesting system installed at the club has a sand filter, which filters silt from runoff
harvested from roof, lawns and parking area. The cost of the filter is around Rs 60,000.
For more details, contact
EA Water PVT Limited,
504 empire apartments,
Mehrauli-Gurgaon Road,
Sultanpur
New Delhi-110 030
Phone: 011-2680062
Website: www.eawater.com
Filters available in the German Market
According to Wessels (1994), concerns over the possible negative health effects of rainwater
utilisation led to some opposition. The Federal Office of Health, for example, intially objected to its
use for washing clothes, personal hygiene and even for toilet flushing, due to possible risks of
infection and allergic reactions. Long-term investigations by the health offices in Hamburg and
Bremen, however, have yielded positive results with respect to the use of water for washing
purposes and have confirmed that rainwater sources do not present a health risk.
(i) Filters developed by WISY
Private companies such as WISY, based in Kefenrod in Germany, are playing an important role in
promoting rainwater use by developing pumps and filter devices to improve water quality. WISY
has developed a simple filter system, which can be attached to a standard household downpipe.
Under conditions in Germany (assuming a mean annual rainfall of 650mm/year), this can divert
and filter 90 per cent of the runoff from a roof area of up to 200
square metre.
(fig a). A filter collector diverts 90 per cent of rainwater to
a storage tank through a 0.17 mm stainless steel mesh filter.
(fig b). A larger vortex
fine filter can cope with run-off
from roof areas of up to 500
square metre.
(fig c). A floating fine suction
filter for ensuring that the
water pumped from the tank is
extracted from the cleanest
part of the tank and is free of
particulates has also been developed.
For details contact:
WISY (Winkler system)
OT Hitzkirchen, Oberdorfstrasse 26,
D-63699, Kefendrod-Hitzkirchen
Germany; fax:+60-54-912129
(Source: John Gould and Erik Nissen-Petersen, 1999: Rainwater Catchment
Systems for Domestic Supply - Design, Construction and Implementation,
Intermediate Technology Group)
(ii) Filters developed by MALLBETON
Another company, MALLBETON, a manufacturer of concrete
tanks and filters, based in Germany, is marketing a tank design which manages any overflows
(a)
(b)
(c)
Contoh untuk jenis filter yg sesuai (contoh lain)
From: Budi Prasojo
Sent: Wednesday, September 14, 2011 9:52 AM
To: Ecep Komarudin ([email protected]); Emin Bunyamin
Subject: Desian Sederhana untuk Penampung air Hujan
Rain Harvest
rain harvest? yah menampung air hujan! (perhatikan bahwa tampungan pertama yg umumnya kotor
dibuat system sederhana untuk dibuang (mas wan Dhamar ini bisa untuk SS)..Cara menampung air
hujan yang lebih baik (menggunakan filter)
Rainkeeper Downspout Filter
Perfect for smaller systems with a maximum roof area of
115m2 (per downspout).
Leaves and debris are continuously and reliably filtered
out through a unique two stage cascade filter. Water flow
is not altered as rainwater enters the top of the filter and
exits the bottom with dirt and debris being discharged out
the front. Installed in the lower section of the downspout
for easy monitoring and discharge of debris. Filter unit is
easily removed for cleaning. Housing and inner parts are
made of high quality, recyclable, PE plastic with the filter
material made from 550mm stainless steel mesh.
Advantages of this product:
• Easy installation
• Secure reliable operation
• Simple to maintain
• Great performance at a great price
Rainkeeper Downspout Collection Filter
This clever product is a perfect match for rainbarrels or
smaller storage tanks.
Leaves and debris that cause sludge build up and poor
water quality are removed through a Stainless Steel
mesh, allowing the cleaned water to enter the rain barrel
or storage tank. Easy to install into existing rectangle or
round downspouts. Provides side discharge of filtered
rainwater. Dirt and debris continue through the
downspout. Made from tough, durable, and recyclable
PE plastic. Easy to maintain with removable filter
cartridge.
The benefits of using rainwater in the garden are:
• plants grow better in pure rainwater
• no unnatural hardness or chlorine in rainwater
• rain can be stored near the points of use
• saves money, helps conserve wetlands
For best results use only filtered rainwater as the water
will be cleaner to use with no odor or sludge build up in
the bottom of your tank, reducing the risk of bacteria
growth and eliminating clogged drain valves.
Available in Black, Brown, or Gray.
Rainkeeper Cistern Filter
Ideally suited for small to mid size systems where filter
installation inside the storage tank is desired. Incoming
water from a maximum roof area of 200m2 , is
continuously filtered through a two stage cleaning
system. The first stage removes larger debris such as
leaves and other organic matter, which protects the finer
second stage from clogging. After the finer particles are
removed in the second stage the clean water flows into
the storage tank through the calmed inlet. A small
amount of water carries the dirt into the overflow of the
tank. Two stage filter is easily removed for cleaning or
can be automatically cleaned with installation of a Back
Washing Device. Filter housing is made of high quality,
recyclable, PE plastic, with the two stage filter material
made from stainless steel. Height difference between the
filter inlet and outlet is just 117 mm. This filter works
well in combination with the RainKeeper Duo Siphon as
the overflow device.
1: Rainwater arrives at the first stage of filtration.
2: Leaves and larger dirt particles are washed away with a
small amount of water.
3: Pre-filtered rainwater containing finer dirt particles
then passes through the second(finer) filtration stage
where finer particles are washed away with a small
amount of water and the clean water flows to the
rainwater storage tank.
4: Filtered rainwater is led through a flow calming inlet
into the rainwater storage tank.
5: Dirt is quickly washed away due to the steep incline
and smooth surface structure of the fine filter.
Rainkeeper Volume Filter
The Self-Cleaning Filter: Innovation By Design
Rainwater filter for small to mid-size systems where
underground installation is desired. Unique dual cascade
filtration provides a high level of filtering efficiency,
independent of flow rate, for roof areas to 450 m2. Self
cleaning, low maintenance filter provides continuous
filtering of dirt particles to .55mm. Extension tube is
adjustable from 250mm to 750mm and includes a lid that
will support pedestrian loading. Filter housing is frost
resistant and made out of high quality, recyclable, PE
plastic, with the secondary mesh made from stainless
steel.
1: As rainwater arrives, the water level builds up until it
overtops the filter lip, providing equal distribution across
the full width of the filter cascade.
2: Larger debris is removed by the filter cascade and
washed downstream with a small amount of rainwater.
3: Pre-filtered water falls through the filter cascade and
flows over a secondary filter sieve (mesh size 0.55
mm)removing the finer particles. Due to the special
structure of the sieve mesh, any dirt is washed directly
downstream making the filter self cleaning, with minimal
maintenance required.
4: Cleaned water flows to the rainwater storage tank.
5: Dirty water flows downstream.
Rainkeeper Basket Filter
Rainwater filter for small to mid-size harvesting systems
where all dirt from roof areas up to 250m2 is retained in a
stainless steel basket. Can be installed within a rainwater
storage tank or in the ground before the tank using
the Telescopic Extension Set with lid.
Rainwater may enter the filter from either or both of the
inlets or one inlet may be used as an emergency overflow.
Rainkeeper Industrial Filter
Rainwater filter for large roof areas where underground
installation is desired. Unique dual cascade filtration
provides a high level of filtering efficiency, independent
of flow rate, for roof areas starting at 850 m2. Self
cleaning, low maintenance filter insert provides
continuous filtering of dirt particles to .55mm. Filter is
located in a concrete manhole or vault. Quality
constructed out of stainless steel for lasting
operation. Filter insert can be easily removed for
cleaning.
1: As rainwater arrives, the water level builds up until it
overtops the filter lip, providing equal distribution across
the full width of the filter cascade.
2: Larger debris is removed by the filter cascade and
washed downstream with a small amount of rainwater.
3: Pre-filtered water falls through the filter cascade and
flows over a secondary filter sieve (mesh size 0.55
mm)removing the finer particles. Due to the special
structure of the sieve mesh, any dirt is washed directly
downstream making the filter self cleaning, with minimal
maintenance required.
4: Cleaned water flows to the rainwater storage tank.
5: Dirty water flows downstream.
Rainkeeper Floating Inlet Filter
An air-filled ball suspends the floating inlet filter just
below the water surface where the cleanest water resides.
A high quality 1” dia flexible hose allows for connection
of the floating inlet to a pump or suction line. Filter is
made out of lead-free brass with a 1.2 mm stainless steel
screen and a built in check valve.
Rainwater Recycling
I have now perfected a method of using rainwater to flush two toilets in the house.
I had been inspired by the, now outdated, details at the Ecocentre which described a method of using rainwater for flushing the toilet. Unfortunately this project got off to a bad start. I got a system working which pumped our well water up into an additional holding tank in the loft, which in turn supplied two toilets in the house with well water. Unfortunately although the well water is fine for watering the garden, the amount of sediment caused a high level of domestic disapproval as the toilet flushing water was a distinctly wee-like colour! When compared to the clinical whiteness of our new bathroom suite, a fast return to mains water was insisted on.
A water filter was installed in the system, but this lasted only one week before the water was again unacceptable. Below are the details of my latest improved rainwater harvesting system.
The rainwater harvesting project has moved a stage further on as I have acquired a 1000 litre IBC tank and a 12 volt pump, shown above. The tank came from eBay at £30 and the pump, brand new, at a bit more. Check eBay auctions for a suitable water tank. You can find a suitable pressure pump too. Look for one with around 30 psi capability if you need to pump to an upstairs or loft tank.
The tank was supplied bare on a wooden pallet, so I have boxed it in with weatherboard, built to look like a little shed. The inlet filter was a Drainsmart, which removed the worst of the leaves and sediment before they entered the tank. There is a high level float switch in the loft tank controlling a relay to operate the pump when water is required, but another low level float switch to stop it if the garden tank is low.
The Drainsmart filter worked quite well, but needed cleaning manually after each rain shower. So I have replaced it with a 3P Technik Filter Collector which is fantastic as it is self-cleaning and requires only occasional inspection by means of an easy access port at the side. This unit is much cheaper than the German Wisy rainwater filter. I am pleased to say that I can now offer these filters at only £49.99 including UK delivery. Click the button above to buy. Read more information on the 3P Rainwater Filter Collector. Here is a large pdf of the 3P Filter Collector.
Calmed Inlet
Water leaving the filter enters the storage tank through
the 'calmed inlet'. The inlet prevents the disturbance and
re-suspension of fine sediments that gather on the bottom
of the tank. Another important function of the inlet is the
introduction of oxygen into the lower layers of the tank
which maintains a fresh supply of water while preventing
anaerobic conditions from forming.
Mono/Duo Overflow Siphons
Once a maximum level is reached in the tank, the
innovative overflow siphon, with its skimmer effect,
removes particles lighter than water (e.g. flower pollen,
oils, etc.) that float slowly to the water surface. Removing
this floating layer of surface pollutants through regular
overflow from the tank is important in order to maintain
high quality water and allowance of oxygen diffusion at
the water surface. The narrow slits in the overflow siphon
prevent rodents from entering the tank.
Mono and Duo models are pictured here. The Mono unit
is used when the filter is located somewhere outside the
tank and the Duo unit is normally used in combination
with the RainKeeper Cistern Filter as shown in the
diagram.
Standard Overflow Siphon
Once a maximum level is reached in the tank, the
innovative overflow siphon, with its skimmer effect,
removes particles lighter than water (e.g. flower pollen,
oils, etc.) that float slowly to the water surface. Removing
this floating layer of surface pollutants through regular
overflow from the tank is important in order to maintain
high quality water and allowance of oxygen diffusion at
the water surface. The narrow slits in the overflow siphon
prevent rodents from entering the tank.
This model is well-suited for PE tanks.
Flexible Suction Hose with
Floating Inlet Filter
An air-filled ball suspends the floating inlet filter just
below the water surface where the cleanest water resides.
A high quality 1-inch diameter flexible hose allows for
connection of the floating inlet to a pump or suction
line. Filter is made out of lead-free brass with a 1.2 mm
stainless steel screen and a built in check valve.
Flexible suction hose is specially formulated to resist
biological activity and is available in custom lengths.