Around California, municipal water districts have set use limits. For example, in Contra Costa, the East Bay Municipal Water District (EBMUD) declared a stage 4 critical drought and set a target of a 35-gallon daily water use per person. Accompanying such restrictions is usually a list recommending appliances that may be purchased to reduce water use. Unfortunately, the information available to purchasers is usually insufficient for informed decisions.
A How-To Guide
This article covers how to purchase and evaluate a single appliance for reducing water use, the ordinary shower head. I chose it for two reasons: First, a shower is a very personal activity. What I write below is intended to provide any person with rational choices to save water, while showering in a way that is both practical and comfortable. Second, information about shower head rating is simple, but not readily available and sometimes confusing.
The U.S. Energy Policy Act of 1992 requires that all faucet fixtures manufactured in the United States restrict maximum water flow to or below 2.5-gallons per minute (2.5-GPM). The recent EPA “Water Sense” lowers that requirement to at or below 2-GPM. “Low-flow” shower heads are supposed to operate at or below 1.6-GPM, depending on the water pressure. Unfortunately, labeling of products lags considerably behind the proposed regulation.
A Trip to the Hardware Store
If you go to Ace Hardware, Discount Builders, Home Depot or any specialty bath appliances outlet, you will find that many shower heads displayed provide NO information about how much water is used per minute of shower. Others show ratings in excess of 4-GPM, or a single rating of 2.5-GPM. Very few show ratings in a table pairing flow rate with water pressure. Usually the overall display lacks adequate information to enable you to make an informed decision. Rarely do any of the employees have explanations that are correct, or reflect simple middle-school physics.
Here is why simply turning down the water volume does not work. Water flow rate is a function of both water pressure and the total area through which the water flows. Turning down a conventional shower head with many large holes over a large area results in a “dribble” shower.
So, what does “low flow” require? First, limiting the total water flow rate without decreasing pressure, by means of a special restriction inside the shower head. Second, greatly reducing water droplet size through very tiny holes. This results in high droplet velocity. Third, focusing the droplet stream into a smaller area. These four physical constraints maintain the physical stimulus and rinsing ability of a comfortable shower, while greatly reducing the volume of water actually used.
Whedon Products Ultra-Saver shower head models USB2C, USB3C and USB4C have detailed flow-rate information on the back of the package. In these tables the PSIG is water pressure in pounds per square inch gauge pressure. In California, most municipal water pressure varies between 60-PSIG and, rarely, as high as 80-PSIG. All of these shower heads are sometimes called “needle spray shower heads.” These shower heads are made of chromed brass, with stainless-steel interior parts. Similar products are made by some other companies, but I did not test those products because Whedon provided the best information.
Typically, the nominal flow rate of the “Delux Ultra Saver,” rated at 1.5-GPM on the front and back of the package, is 1.5-GPM between a pressure of 40-PSIG and 80-PSIG. It comes with a push-button “flow-control” valve built into the shower head and costs about $16. Buying it without the control button only reduces the price about $3. A separate control valve, much easier to use because it can be turned costs about $4. I tested both kinds on my shower. The shower head is at the end of a chrome-flex hose and fits in place on the wall be means of a pin – so it can be used as a hand-held shower or a mounted shower. Now the clever thing about these needle spray shower heads is that the force of the spray and the shape of the “cone” of spray coming out of the shower DOES NOT VARY SIGNIFICANTLY WITH FLOW RATE…! You won’t get the “ultimate pounding” at the lowest flow rate, but it is a very satisfactory shower.
I tested both configurations by measuring the time to fill a quart measuring cup (a “quart” is 1/4th-gallon). At full flow, both configurations provided 1.6- GPM. The “built-in” control gave a weak shower at half setting and was difficult to adjust. At lower flow settings, the head with separate flow valve worked best, providing a comfortable “shower effect” when turned down to give 1-quart in 30-seconds.
So, now I simply set the control to deliver a measured two quarts of water in about a minute. There are four quarts in a gallon, so this is about 0.5-GPM. This gives me a nice, comfortable five-minute shower that uses 2.5-gallons of water per shower. With warm-up flow, that probably comes to three-gallons per day.
Which, writing of warm-up flow… I set my water tank temperature to deliver water at a temperature which I can endure on the skin of my hand. It is very energy wasteful to set the water temperature higher – and, also, dangerous. This means I use very little cold water in my shower. How smart is it to heat the water, then cool it down with cold water? This speeds warmup time; it also avoids temperature changes when I adjust the flow rate, because the hot water pressure is slightly lower than the cold water pressure.
This article first appeared in the March 02, 2016 issue of the Rossmoor News, author Wayne Lanier