Get in the shower and select your desired water temperature on a small screen. Once you press start, water begins to flow just like in a normal shower, the difference is that instead of the water being wasted by letting it go down the drain, it's collected and pumped though several filters:
After passing through the filters the water is clear, clean and bacteria free and ready to be pumped back into the shower head. A small electrical resistor can be used to reheat the water to your set temperature. When you are done the water goes down the drain like normal or you can use the water for something else, like doing your laundry or flushing the toilet to save even more water.
The water needs to be collected for the pump which needs to be placed at the lowest point of the shower, ideally under the basin. If you have an Italian-style shower you can build a new basin instead of tearing the floor apart. We are also working on a way to hack your existing drain and using self-priming pumps so that you can plug the drain during loop mode and suck the water out of the small collection basin.
Multiple sensors and a micro-controller are used to allow for complete monitoring and control of the system so you can understand more about your own behavior and personalize the shower to fit your needs (e.g. tell you when to get out of the shower in case you’re in a hurry). You can set your ideal showering conditions like flow rate, water temperature, ambiance and to automatically wash the filters once you've left the shower so that the filters last longer before requiring manual maintenance. By measuring use and changes in flow rate it can inform you when to change filters.
Currently we are using a simple two-row, two-color LCD screen (below) but in the future the interface could look more like this and be programmed by your smart phone (it's just a draft so don't get caught up on the numbers - it's only an example).
Two different setups for the filter. One the left is the POC21 model (see the DIY instructions) made with copper pipes and without the automated control system and slightly smaller filters for a lower flow rate. On the right is the fully operational prototype shower built for 10 l/min and automated piping. Instead of copper pipe, drinking water hose was used. This was used for testing and fast iterations. The image on the left more closely resembles the final product but the placement and look of the filters can be modified by the user.