A complete domestic gravity fed rainwater harvesting system with mains water top-up.
This system has everything you need to filter, store, and pump rainwater to the point(s) of use. All you need to supply is the rainwater collection and distribution pipework.
This 6,800-litre domestic gravity-fed system is generally suitable for medium to large projects, and these are typically installed into a 3 to 4 bedroom dwelling.
Rainwater storage tank
Our 6,800-litre underground storage tank is complete with a pedestrian rated telescopic neck (extendable by up to 300mm), pedestrian rated lid, push fit DN100 drainage connections, in-tank-filter, and calmed inlet.
Made from polyethylene plastic in the UK, it has a unique ribbed design for extra strength. Thanks to its low profile design, only a shallow dig depth is required. It most cases it can be installed without the need for concrete.
In-tank rainwater filter
The system is supplied with a choice of 3P Technik in-tank filters:
1) Compact filter suitable for roof areas up to 150M2
2) PF filter suitable for roof areas up to 200M2
3) VF1 filter suitable for roof areas up to 450M2 (twin neck tank required)
The filter is pre-installed into the neck of the tank, where is it joined to the also pre-fitted calming inlet.
This filter removes leaves, grit, and other debris from the incoming water up to approximately 1mm.
Finer particles form a “scum layer” and are washed away during overflow or filtered out by the secondary filtration.
The filter is easy to clean. There are no consumables- just lift, rinse, and replace for continued use.
Twin neck tank option
This tank has a twin neck/access opening option, which is supplied with 2 x telescopic necks and 2 x pedestrian rated lids.
Due to the size of the tank, we recommend this option for better tank and interior component inspection and maintenance.
However, the twin neck tank is a must if you opt for the VF1 filter. Due to the size of the VF1 filter, it will fill the access opening completely which leaves no room to inspect or maintain the interior of the tank or any internal equipment.
DAB submersible pump
This system is supplied with a highly reliable DAB Divertron 1000m submersible pump.
It delivers approximately 4 bar of pressure and up to 3,500 litres/hr of flow.
The pump starts and stops automatically by its integrated control system. It has dry run protection, a built-in non-return valve, and a screened filter as standard.
It is suspended from a pre-fitted hook in the neck of the storage tank by a stainless steel chain. It comes with a high-quality large handle, for easy lifting when if necessary.
This system also known as an indirect pressure system, uses a header tank that needs to be installed in a location higher than the point(s) of use. In most installations, this will be in the attic space of a building.
The gravity controls are pre-fitted inside the header tank along with pre-drilled inlets and outlets.
The header tank is delivered to site assembled, tested, and ready to install.
How does it work?
Water is pumped to the header tank from the storage tank via the submersible pump.
When demand is placed on the header tank, water is gravity fed to the point of use.
Our header tank has a mechanical delay action; this means that a WC or similar demand can be flushed 4-5 times before the pump starts and fills the header tank completely in one go.
Should the underground tank become low, the header tank will continue to be depleted until the level has reached the main water top-up level. At this point, mains water is introduced directly to the header tank.
As the pump is starting and stopping less frequently than with direct pressure systems, the power consumption along with wear and tear of the pump will be much less.