Proof of concept experiment: Recycling Shower Plumbing, 1/23/09

The experiment started at 12:05 PM in the workshop laboratory with approximately 15 Gallons of water in the holding tank. The components where: a 25 gallon holding tank under the shower base, a pump/pressure tank combo, an aqua sun US200-3 (three filters and UV), a tankless water heater, a faucet/shower fixture and a shower base to collect the water.

 

I primed the pump and charged the system. The pump is designed to turn-on at 30 pounds of pressure and turn-off at 50 pounds of pressure. I started the water flowing through the shower faucet at 12:05PM. The flow rate was approximately 1 gallon per minute. The water temperature after about two minutes of running was 60 degrees.

 

The pump would restart about every minute and 50 seconds (I went through approximately 25 on/off cycles for the pump, and it ran fine). The experiment went well except for the excess splashing of the water, and I did not actually run any water through the shower head, because the shower base was not sufficient to capture all the water, and much was splashing out of the capture area. If I had run the shower, the splashing would have been worse. I collected a pint of water from the faucet 30 minutes into the experiment, and labeled it “baseline water sample”. I ran the system until 12:50PM when the holding tank didn’t have enough water to draw properly, and the pump air-locked. At the end of the experiment the water temperature had reached 102 degrees (I need to adjust the tankless heater to a hotter setting – next week). I was able to add 2 gallons to the holding tank then re-prime the pump and boot the system back up; but ceased further experimentation for the day.

 

In summary, the concept of recycling the water seems valid from a plumbing standpoint. Even the crude plumbing system that I constructed from off-the-shelf components seemed fairly efficient. I’m encouraged that as we design components to match the shower stall, components that are more customized and coordinated, the system will be elegant and provide a typical shower experience.

 

Next week, I plan to begin basic filtration experiments. I have about 5 gallons of shower water at the cabin, and plan on adding it to the water in the holding tank. I will then run the system for 30 minutes and take a water sample. I will then take the baseline water sample and the second sample to get tested for comparison. My hope is that the existing system will clean the water back to the baseline quality. I doubt that this will be that easy, however. Larry and Nathan (IUP Chemistry Professors) think that additional treatment of reverse osmosis may need to be added. We’ll see.