There is a huge amount of water wasted by letting a shower or faucet run while waiting for the water to get hot. Let’s see if we can figure out just how much water is being wasted, which will give us the number of gallons we can save by installing a hot water recirculation system.
The average American showers for 8.2 minutes at a flow rate of 2.1 gallons per minute.
In my [average sized] house, I had to wait about 3 minutes for the water to get to an appropriate temperature before stepping in. This means I wasted 6.3 gallons per day waiting for the shower.
My kid’s shower is in a different wing of the house, so assuming that 1/2 of the piping going to his shower is unique to mine, we’ll say that he wastes 1/2 of the amount that I do, or 3.2 gallons per day.
Using just these numbers, we arrive at (6.3+3.2)*365 = 3,400+ gallons per year of wasted water.
Being an engineer, I’m going to arbitrarily add 50% on to that number for the following reasons: We’re active, so we often take multiple showers per day, and, we haven’t factored in sink/faucet usage at all.
I feel very comfortable saying that if you have two people in your household, you will save at least:
That’s right! You can save:
5,500 Gallons per year