730102Propelair 2ClosedLegacy RDA Grant for R&DInnovate UKOver recent years there has been a strong drive by governments to reduce the volume of water used in flushing toilets. Propelair is a radical new approach in that it utilises a large volume of air at a small positive pressure, with just 1.5 litres of water to create the flush. This is not a compressed air system and has the major advantage that it complies with current building regulations and can connect to standard drains (unlike vacuum and compressed air systems). It is directly compatible with existing plumbing systems and simply replaces conventional WCs. A very successful six month trial with two early prototype units at Greenwich Council has saved over 40 tonnes of water and is still ongoing. There are two major elements to this project: the design of each component for function and lowest cost of assembly, and the design of the complex tooling required to achieve this. The latter will be the most technologically challenging. Separately the elements of the proposed development project are: 1. Complete development of the integrated air flush very low water lavatory following on from the recently successful GRaD research project. To conclude with testing to EN997 at theWRc. 2. Design and develop the air pump’s new modulardesign into an assembly of two halves suitable for injection moulding, and especially the design of associated complex injection mould tooling. 3. Design, develop and trial tooling for the cistern container assembly to be compliant with Fluid category 5. Again the mould tooling design will be complex, not least as space is restricted. 4. Develop and trial WC lid components and endurance test them to 200,000 operating cycles. Earlier Polyurethane parts have been found to fracture and fail regularly. 5. Redesign the ceramic WC pans as the current approach has a high failure rate because of drying problems. Also the air and water entry ports need to be designed and incorporated into the ceramic pan, replacing existing high cost plastic parts. 6. Design, fabricate and test a Helmholtz resonator to reduce vibration generated by the air pump. This proposed Development Project follows on from an earlier successful GRaD Research Project supported by the London Development Agency (LDA), also involving STEP and Enterprise Bureau University programmes. Prototype WCs derived from this project have been tested at the Water Research Centre (WRc) and showed performance in excess of EN997, with significant reductions in water and energy use together with high levels of user acceptance.