So . . . I finished taking out the trash, garbage, and recycling materials to the curb and, as is my wont, I took to the kitchen sink to wash my hands. Because I’m far more acutely aware of our water use due to the drought, I ended up washing them with cold water; I just didn’t want to let the water run long enough to get hot.
That got me wondering about how much water could be saved if we had instant water heating. I did a little research into tankless water heaters and quickly found out how little the technology seems to have progressed in the last 10 years or so. Most articles I came across suggested the break-even point for installing one that was reasonably efficient/effective would probably exceed your lifespan.
In the process, I came across figures for the number of gallons of water an average household runs down the drain while waiting for the hot water to push out the cold that’s in the pipes between the sink/tub/shower where it’s going to be used. The figure I came across is 26 – 29 gallons. I also looked at the US Census to see how many households there are in California. The number of housing units listed, as of 2013, is 13,790,495.
So, taking the number of households and multiplying by the more conservative number of 25 gallons per day down the drain, I determined the following. If we could find a way to heat water directly at the point of use, thereby not wasting that 25 gallons per day, the State of California would save 125,838,266,875 gallons of water per year. As it turns out, that’s a third of one percent of the water in Lake Tahoe. Drop in the bucket, or significant savings? Probably doesn’t matter, unless you’ve got an idea for how to provide on-demand, on-location hot water . . . cheap.