When designing the rainwater harvesting and filtration system, the EWB-PU AHI team had to keep several constraints in mind:
- The design had to cost less than $200 per system.
- The materials must be able to be purchased locally at Arial Home sites.
- The design must be to be scalable and mass-produced.
- The models must be easily repairable with minimal skill and local materials.
- The rainwater catchment and filtration system must produce 1 gallon per person per day during the summer and half that in the winter: for the average eight-person family, that equates to 8 gallons a day during the summer and four gallons a day during the winter.
After extensive research on both pump-driven and gravity-driven rainwater harvesting systems, the EWB-PU AHI team decided to construct a gravity-driven system with a ball-and-seat first flush diverter. With the help of Mike Vocaturo, manager of the fluids and thermodynamics lab in the Department of Mechanical Engineering (Princeton University), the EWB-PU AHI team designed a platform for a 55-gallon cistern to store the water collected from the roof of the Arial Home that ran down from the gutters.
A schematic of the cistern platform. Note that there will be crossbars on all four sides of the platform.
From the cistern, the water will be fed down through PEX tubing to a filtration system developed by Professor Wole Soboyejo in the Department of Mechanical Engineering (Princeton University). These filters are embedded with silver ions that treat the water, killing over 99% of pathogens.
The EWB-PU AHI team is currently constructing its first prototype. As the design is refined, we will begin creating Google SketchUp models and post them on this page. Please stay tuned!
Brenton and Andreas drilling together the cistern platform top.
