Water will be an essential and stressed resource in California, the West, and in any hot, dry climate far into the future. Politics and economic forces are at play regarding water and other natural resources. Besides advocating for local, state, national, and international safeguards on an affordable water supply, we can do something positive at home to save water and make a difference. We all depend on clean water to live, and when water resources are scarce somewhere, they affect us everywhere. Here are some serious and less-than-serious steps to being water-wise at home. Otherwise, things could get too serious.
On-Demand Hot Water Systems
My wife and I just moved into a remodel that you may have read about in recent editions of this newsletter. The job is mainly done, and we are getting used to our home's new surroundings and features, like a heat pump for cooling, a heat pump water heater, and an induction cooktop stove. All are amazing and promise to make us happy when the next PG&E bill comes.
But we have been waiting a long time for water to get hot in our bathrooms and kitchen and are worried about wasted water. When we started this process about a year ago, our HVAC company recommended we install an on-demand recirculation system. Since the water heater is not far from our water use areas—the house is about 1,700 square feet—we decided we would forgo that upgrade. Now, we are rethinking that.
There is a difference between a recirculating system that constantly recirculates water to the water heater to keep hot water in the distribution lines hot when you need to shower, for example, with a very short wait time. But the constant recirculation keeps the heat pump water heater running much more often, mainly due to the water constantly losing heat throughout the plumbing system. And you are using electricity constantly to run the recirculation pump, as well as more energy to enable the water heater to boost the water temperature more often.
An on-demand recirculation system only turns on when you tell it to. The recirculating pump is installed in the farthest water-use area from the water heater, often the primary bathroom. When you are ready to shower, turn on the recirculating pump, which pumps cooled water from the hot water plumbing back to the water heater until the water is hot at the point of use—very little water is wasted. You can operate the pump remotely from other bathrooms and kitchens. Some systems are set on a timer to ensure hot water is ready for showering in the morning or when you come home from work.
Water and Energy Saving Shampoo-ing
Did you know you could cut showering time by at least one minute by combining your shampooing and conditioning into one step? You might want to research at your local supermarket and look for a combination of shampoo and conditioner that works.
A study commissioned by the California Department of Water Resources examined water use in California single-family homes. The study determined showering was the third largest water user inside a house, after toilets, which are the most significant users, and washing machines, the second biggest.
There are about 39 million people in California. Each person uses about 18 gallons of water daily for a shower. Baths generally use as much or more water than showers. The average shower lasts about 9 minutes. The average flow rate is about 2 gallons per minute. If just 10% of us switched to a combination shampoo and conditioner, shaving at least a minute off of our shower time, it would save the state:
1/9 minutes x 18 gallons per day x 365 days x 3.9 million people = 2,847,000,000 gallons of water each year
Depending on the person's preference, anywhere from 50%–75% of the water in a shower comes from the water heater. Heating a gallon of water from 60F to 105F takes about 375 Btu, equivalent to 0.1 kWh. For $0.34 per kWh, heating a gallon of water costs about 3.4 cents. Suppose half the water used in a minute of showering is heated water, and one out of ten of us switched to a combination shampoo and conditioner. In that case, the amount of energy we could save and the cost of that energy is about:
2.847-billion gallons x 0.5 x 0.1 kWh = 142-million kWh of power saved each year
and
142-million kWh x $0.34 per kWh = $48-million saved each year
For an individual, switching to a two-in-one shampoo and conditioner could save more than 730 gallons of water a year and save about $12 in energy costs.
Additional Resources
Water saving ideas from EBMUD and Contra Costa Water District
Portions of this article were excerpted from a KQED Quest blog post.
Photo by DAVIDCOHEN on Unsplash
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