Solar Shower and Greywater
In Summer 2017 we installed an outdoor shower, outdoor sink, and a two zone grey water system to distribute the drain water from these two plumbing fixtures to our vegetable gardens. The incoming water, which comes from our well, is heated by an inexpensive (about $75), homemade, solar collector, which raises the temperature of the incoming water from the temperature of the earth, which is about 60 degrees °F in the summer, to almost 120°F, much hotter than needed for showering. (For comparison, a typical hot tub’s water is kept about 105 °F.)
Like a normal shower, it is equipped with cold water and a mixing valve to adjust the temperature to a comfortable level.
Once the shower was installed it got enthusiastic use from multiple residents taking advantage of the chlorine free hot water, and the bright and sunny outdoor location. Due to the thermometers we installed we were able to note the temperature of the hot water reaching the shower. Highest so far recorded was 125 F. A water meter also allowed users to gauge how much water they used for the shower.
The solar collector is constructed of a coiled 1.25 inch polyethylene pipe totaling about almost 100 (96′) feet in length. It is is quite lightweight and is supported directly on a rooftop right above the shower. It quite effectively heats the cold water. This length of pipe contains about 7 gallons of heated water.
Our installation was perfectly timed to coincide with a professional grey water installation workshop sponsored by Depave and led by grey water guru Laura Allen. The greywater installation received a permit from the Oregon Department of Environmental Quality.