Key Engineering Takeaways
- Patented vertical vortex separation directs 90%+ of rainwater through a 0.28mm stainless steel mesh while washing debris into the storm drain.
- Complies with DIN 1989 German rainwater standards for non-potable and potable household utilization.
- Smoothing inlet gently diffuses incoming water, preventing agitation of beneficial anaerobic benthic layer at the tank floor.
- Floating suction extraction draws water 15 cm below the surface where dissolved oxygen is highest and purity is pristine.
Why Most Indian Rainwater Harvesting Systems Fail
Traditional rainwater harvesting in India frequently relies on simple horizontal wire mesh strainers or sand-and-gravel pits. During monsoon downpours, leaves, bird droppings, and atmospheric soot quickly blind horizontal screens. The water backs up, spills over roof gutters, and turns underground collection tanks into stagnant, foul-smelling cesspools.
The German 4-Stage Engineering Philosophy (DIN 1989)
Engineered by WISY AG in Kefenrod, Germany, the 4-stage rainwater management architecture addresses physics rather than fighting it:
- Stage 1: Vertical Vortex Fine Filtration (WFF 100 / WFF 300) — Rainwater enters vertically. Centrifugal force spins the water against a cylindrical 0.28 mm (280-micron) stainless steel mesh. Capillary attraction pulls clear water outward through the mesh into the storage tank, while twigs, moss, and dirt fall down the center into the sewer.
- Stage 2: Calmed Smoothing Inlet — Water entering the tank is piped to the bottom and discharged upward through a bell-shaped diffuser. This prevents turbulence from stirring up fine settled sediment.
- Stage 3: Overflow Siphon with Skimmer Effect — Pollen and lighter-than-water oils floating on the water surface are automatically skimmed and flushed away when the tank fills to capacity.
- Stage 4: Floating Suction Extractor — Rather than taking water from the bottom (where sediment settles) or from the surface (where oils float), the pump draws water from 10 to 15 cm below the water line using a floating air sphere.
| Specification | WISY WFF 100 | WISY WFF 300 |
|---|---|---|
| Roof Catchment Capacity | Up to 200 m² | Up to 3,000 m² |
| Filter Mesh Size | 0.28 mm Stainless Steel 316 | 0.38 mm Stainless Steel 316 |
| Water Recovery Efficiency | Over 90% in normal rainfall | Over 95% high-volume flow |
| Vehicular Load Capacity | Up to 30 tonnes (under driveway) | Up to 60 tonnes (industrial) |
Real-World Benefit for Bungalows in Gujarat
A typical 5,000 sq.ft. villa in Ahmedabad receives enough monsoon rain to harvest over 250,000 litres of sweet, soft water annually. Stored properly through a WISY 4-stage system, this water remains crystal clear for up to two years without chlorine or chemical dosing.
WISY Vortex Fine Filter WFF 300
Precision German vortex separator with 0.28mm stainless mesh and self-cleaning hydrodynamic wash.
Jal Tatva Water Engineering Cell
Authoritative technical publication based on real-world test data and official engineering specifications from WISY AG. Consult with our specialists for turnkey project design.
