Collecting and storing rainwater
Thanks to the comments, diagrams and photos sent to us by one of our website readers, Mr. Teije Penninga, we now know all there is to know about building a rainwater collection installation. Thanks Teije!
Following one minor adjustment, the installation has a fully functioning and extremely practical design. The main collection point is 4 barrels, each with a capacity of 200 liters. The roof water is collected via the roof gutter, rain pipe and rain barrel dispenser. The latter, made from a rain pipe, is a middle-piece and used for the existing rainwater drainage pipe, which you can buy at most general hardware stores. The rain barrel dispenser, mounted above the highest point of the barrel, is connected with a horizontal pipe. When heavy rain fills up the barrels, the rainwater then runs normally, via the dispenser, through the normal rainwater drainage pipe.
The four storage barrels are connected to each other via a watertight pipe that runs between them 10cm from the bottom of each barrel (for this, Teije uses kitchen sink plugs). Eventually, dirt and other matter from the gutters sink to the bottom of the barrels. Wire netting in the gutter opening prevents dirt from passing through. The ultimate aim is to replace the four barrels with a 1,000-liter outdoor tank, which is buried in the ground and has an immersion pump hung inside it. Teije advises that you place a drainage trough under the barrels placed inside the house, to protect against overflow.
The most important 'consumer' of rainwater, the flush toilet, is placed, the same as storage barrels, on the ground floor of the house. The toilet receives its water via a storage tank, which is placed in the attic to ensure that the water arrives in the toilet tank with a good amount of pressure (via a floater faucet).
The attic barrel (also having a 200 liter capacity) is automatically filled by a 12-volt immersion pump that is installed in one of the four main barrels and is switched on and off by a floater water level-changer in the attic vat, which in turn is switched on and off by a 12-volt relay connector.
When the pump is activated, the relay connector powers the pump with a 12-volt battery, which is supplemented by a 14.5 volt, 460-mA solar panel, via a control unit. Teije sells these pumps (order number: 53 80 94-01, cap. 22l./min., height 14 meter, ED 50% = may turn 30 minutes per hour), the solar panel (order #. 11 02 72-01, price f.119.95), the accompanying battery units (order # 11 33 44-01, price f. 39,95), the relay connector, etc., are available form mail-order company Conrad (www.conrad.nl). For a battery, remember that a 12-volt battery salvaged from a car junkyard is often still good. Floater changers can also be purchased from Conrad. The toilet reserve tank also has a mains water connection with a faucet and it's own floater in case (for instance, during freezing conditions) there is no rainwater.
Filling up the toilet tank via the barrel in the attic takes 3.5 minutes, compared to 1.5 minutes via the mains water supply. The saving of water used from the toilet is around 30 liters per day, per person!
(email address Teije: t.penninga@hccnet.nl).