Enigmaker

It's not a system for measuring levels in neighbouring rooms, a water clock, a head mounted rainwater detector or a mobile personal enema kit.

This enigmatic tweet was all that subscribers could see to describe the invention until now. I felt the need to let the dust settle on the failure of #project1 while brows were mopped, and scores were settled and #project2 needed clarity before I could get back to tying up those loose ends. Thanks for your patience.

This project could have made a lot more progress on the prototyping front. I think you'll understand my reticence and regret for committing to this partslist. This design is very worthy, but who really wants to get their hands dirty with this stuff....

Bypiss

The bypiss is compatible with an ordinary pedestal toilet with siphoning flush. Both sides of the funnel of flexible plastic are normally held tight against each other at the front of the bowl to limit odours. However, when deployed, the funnel opens wide enough to capture the liquid waste and channel it through the flexible plastic tube, bypassing the S pipe and delivering it directly into the sewer pipe beyond, avoiding the need to flush. The procedure for solid waste is exactly as normal, except that the flushing action forces the funnel open slightly and permits it to be cleaned by the rushing water.

Background

The water-based toilet has been wildly successful perhaps because of its core design principle - to push the problem elsewhere. However, they are environmentally questionable and heavily dependent on expensive public infrastructure. The impact of the design on water conservation has even forced the US government to introduce stringent efficiency measures to force the industry to select efficient designs, against the tide of public opinion.

Dry or composting toilets offer an alternative design which takes avantage of natural breakdown processes to turn waste products into a safe nutritious fertilizer, yet remains unpopular in everyday households.

This all strikes me as a fairly straightforward case of a tragedy of the commons, in which everyone individually would rather take the easy option, and therefore has to suffer the pollution and impact on the water table from everyone collectively.

If it's yellow

Unfortunately the average homeowner simply inherits the design choices of the mainstream and would not consider reengineering their throne. The more pious among us conjure the rhyme if it's yellow let it mellow, if it's brown, flush it down. I have got into trouble applying this principle in the wrong households, and it's understandable that people have a problem with it. Although urine is strictly sterile when it leaves the body, when left dilute in the bowl it can begin to smell as urea breaks down into ammonia.

The Bypiss is intended to address this need in households who care about the cost or environmental impact of their water usage, but don't wish to replace all their plumbing or 'let it mellow'. The surface area of moist urine left open to the air is very small, restricted to the diameter of the tube, and is sealed within a closed funnel. This means that people can afford to avoid flushing for the most frequent visit to the toilet and save a huge amount of water.

Testing and development

As you gathered from the postings this week, development has been sparse to nothing. Having originally developed this idea in clean, well kept homes over previous months I now find myself on the road with the only testing environment being public conveniences. I also encountered a series of design questions which I was unable to address to my satisfaction.

• How to
  • open the funnel without direct contact
  • close the funnel forcefully enough, but without generating an aerosol spray
  • construct the system, especially the seals, without creating recesses which can't be cleaned

Moving on

I'm confident that the principle is sound, but I don't have the skills to design and test this kind of product. I'll be hiding out in software and electronics projects for another couple of weeks until I can get some confidence back.