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Showers account for 18 percent of residential indoor water use.[1] When you consider that the United States uses nearly 1.2 trillion gallons of water a year just for showering,[2] it is easy to see why low-flow showerheads can have a big impact on water consumption and efforts to conserve water at home. (To put this figure in perspective, 1.2 trillion gallons is enough water to supply the water needs of New York and New Jersey for an entire year!)[2]By simply switching to a low-flow showerhead, everyone can participate in water and energy conservation.

The advantages of low-flow showerheads have been recognized by government and environmental organizations alike. Today more groups are pushing for low-flow showerheads and other water conservation techniques. For example, the WaterSense program, launched by the EPA in 2006, reduces water consumption at the residential level.[3] WaterSense has made it easier for households to choose high-performance low-flow showerheads and other water-efficient products that are guaranteed to meet or beat the expectations of water-hungry consumers.[4]

## Relevant US federal programs

Congress passed the Energy Policy Act (EPAct) in 1992, which established production standards for water efficiency, effectively outlawing all plumbing fixtures in the U.S. which did not meet the prescribed benchmarks.[5] Before the EPAct, normal showerheads sprayed water between 5 and 8 GPM. The EPAct set the national standard at 2.5 GPM, hoping to halving shower water consumption.[1] The limitations on showerhead spray, particularly, were met with public disapproval. Many Americans complained that decreased shower head flow would not allow adequate pressure to wash out shampoo or relieve stress. This social stigma surrounding low-flow showerheads led manufacturers to find creative ways to circumvent the new national regulations. Some manufacturers even went so far as to put directions on removing the flow restrictor piece from their shower heads on the packaging.[1] Thus, while federal law requires that all showerheads have a GPM rating of 2.5 or under, many Americans continue to consume more than the legal limit by removing the small washers in their showerheads that restrict flow or even installing more than one shower head in their showers.

The U.S. Environmental Protection Agency (EPA) launched its WaterSense Program in 2006 to encourage consumer awareness for water-efficient products. In partnership with independent third-party organizations, WaterSense tests and certifies home products that meet its water efficiency criteria. Some of these criteria include: products are 20% more efficient than other products in the same category, realize water savings on a national level, and work as well or better than comparable, less-efficient alternatives. In addition, WaterSense has performance criteria to ensure that showerheads are efficient and work well. Starting in 2010, WaterSense labels appear on low-flow showerheads and bathroom sink faucets, toilets, and urinals.[2] It is important to note, however, that WaterSense considers low-flow showerheads to have a GPM of 2.0 or less. For more information on the EPA's WaterSense Program

## Impacts

Water is the quintessential liquid that supplies all living beings with the hydration necessary to survive. Unfortunately, in our modernized homes, it is easy to forget that the water flowing from the tap originated in riparian ecosystems or underground aquifers that are being severely impacted by our casual overuse of water. Indeed, in the United States alone, we consume approximately 340 billion gallons of water from streams, reservoirs, and wells every day.[6] While a great majority of that water goes to crop irrigation, the easiest way we can make a difference in water consumption rates is within our homes.

[7]If everyone in the US switched to 1.6 GPM showerheads, we could fill more than 1 million Olympic swimming pools with the amount of water saved in one year.

Showers account for 18% of indoor water use in American homes.[6] The average American showers every day for about eight minutes, consuming 20 gallons of water.[1] Since 1992, federal regulations have required that manufacturers produce shower heads with maximum gallons per minute (GPM) ratings of 2.5 GPM. By switching to a WaterSense approved showerhead, an eight-minute shower would consume 16 gallons of water, a 20% reduction from the standard.[1] If an individual showered every day, using a 2.0 GPM shower head would lead to 1,460 gallons of annual water savings. However, going one step further and changing to a low-flow showerhead with a 1.6 GPM rating would save 7.2 gallons a day and 2,628 gallons a year compared to a standard 2.5 GPM showerhead. Multiply that by the number of residents in your home, and the savings in water consumption and cost add up! Then, consider the savings on a national level: Let's assume there are about 300 million people in the US. 2,628 gallons x 300 million people= 788 billion gallons of water saved in a year! That much water could fill more than one million Olympic-sized swimming pools.

## Technology

### Showerhead Flow Restrictors (Disk Inserts)

Flow restrictors are small (about the size of a U.S nickel or quarter) plastic or metal discs used within showerheads to limit the amount of water passing through the unit. (See photo)

Flow restrictors are typically seen in older fixtures.[8]

Flow Restrictor Disks[9]

Flow restrictors are an inexpensive tool used mostly to convert older high-flow showerheads to conform to the laws requiring lower flow rates. The problem with flow restrictors comes from how the shower heads operate under these choked conditions; these models were not originally designed to function properly with these lower flows. The result is typically a meager and inadequate shower. It has been noted by those who study low-flow showerheads that disc inserts have a poor acceptance rate by bathers and are typically not used by experienced conservation managers.[8] The solution for most consumers, as noted above, is to remove the flow restrictor, which defeats all efforts to conserve water and permits illegal flow rates in the U.S.

Flow Restrictor[10]

Showerhead flow restrictors are not advised; flow restrictors often lead to the dreaded weak and insufficient shower. Flow restrictors coupled with poor engineering are the major reason low-flow showerheads once had a reputation for providing a poor shower.

When purchasing a low-flow showerhead, avoid units that achieve flow rate through a flow restrictor; high-quality models generally do not contain a removable restrictor disc and rely instead on technological advancements in showerhead aeration other innovations.

### Aeration

Aeration (also called aerification) is the process by which air is circulated through, mixed with, or dissolved in a liquid or substance;[11] in a shower-head, aeration works by combining air into the water stream.

Due to its higher oxygen content, aerated water is lighter and also less dense than non-aerated water. Aerating water increases the volume of the water, making the droplets of water smaller and thus able to cover more area; essentially, with aerated water, less water can be used to wet the same surface. According to Dr. Jie Wu, a leading developer behind showerhead technology, aeration makes the water more like wet pockets of air, "Through aeration, we make the water droplets in the stream hollow and the bubbles expand the volume of the shower stream."[12]For the bather the aerated water gives the same sensation and satisfaction as non-aerated water. Aeration is the most popular and efficient method of reducing water consumption in showerheads; aeration alone can reduce water consumption by up to 30 percent.[13]

Showerheads aerate the water through two techniques.

Venturi Tube[14]

The first is turbulence within the showerhead which effectively mixes the water with air. The second is an ingenious implementation of the Venturi tube. The Venturi tube creates a vacuum within the showerhead; the vacuum sucks air into the unit infusing the oxygen with the water stream. For more information on the science behind the Venturi tube, click here

A criticism of aeration has come from the fact that aerated water loses heat faster than non-aerated water. Alan Meier noted this effect in a column for Home Energy Magazine On-Line, "Aeration is often used in the low-flow showerheads to give them extra body, but it results in rapidly declining temperature between the time the water leaves the showerhead and hits the body."[15] The disapproval arises from the fact that more hot water is used; Meier claims, "Without knowing it, many users raise the temperature of the water 1 deg. F to 10 deg. F to maintain the same 'impact temperature.'"[15] The Pennsylvania State University, however, has come out against this criticism, stating in an article titled "Household Water Conservation," slightly hotter water does not negate the substantial savings achieved by low-flow showerheads.[16]

### Pressure Compensating Flow Regulator

A pressure compensating flow regulator essentially functions by expanding and retracting a particular O-ring against a precision profile. In this way, the flow opening automatically changes depending on the distribution pressure.[17] This flow regulator allows the showerhead to adjust to the specific water pressure of the place where it is installed.

The pressure compensating flow regulator is a feature on low-flow showerheads, allowing the showerhead to maintain the same flow rate over various water pressures. Many low-flow manufacturers believe that failure to incorporate such a mechanism will result in a disappointing showing experience for many users.[15]

The best shower head designs deliver nearly identical flow rates within the typical 40-80 PSI pressure range. For example, the Evolve Roadrunner 1.59 GPM shower head has less than a 6% flow variance within this pressure range.[18]

### On-Off Switches and "SmartStart"

"SmartStart" stand-alone device[19]

Another innovation used in many low-flow showerheads is a simple 'on-off switch located on the showerhead itself. These switches allow users to pause the water flow while washing their hair or lathering. While this innovation does not lower the rate of water exits the showerhead, it still can conserve water.

SmartStart, on the other hand, is an innovation that allows the user to run the water only long enough to warm up before they get in the shower. So if you are the type of person who turns on the shower before you get in to allow the water to warm up, this could help you save water. The technology knows when the water reaches bathing temperature and shuts off automatically. When you are ready for your shower, there is a simple lever to resume the water flow.[20] For more info on SmartSmart click here

## Products

Today there are many excellent low-flow showerheads on the market. Quality low-flow showerheads start around $25. Check out WaterSense's product search page for the most up-to-date information regarding highly efficient and high-performing showerheads. ### What to look for in a low-flow shower head • Clearly-marked maximum GPM flow rate • WaterSense certification logo • WaterSense products are tested for the following criteria • Water efficiency • Spray coverage • Spray force • No removable flow restrictor • Features such as • Aeration • A pressure compensating flow regulator • On-Off Switches and "SmartStart." WaterSense Stamp ### Highly rated 1.6 GPM or less low-flow shower heads on the market Alsons Water Amplifying Shower Head (658) • WaterSense approved • 1.5 GPM maximum flow rate • Comfort spray setting Average Cost:$26

Alsons Water Amplifying[21]

• WaterSense approved
• 1.6 GPM maximum flow rate
• Lifetime faucet and finish warranty

Average Cost: $60 Evolve RoadRunner • 1.5 GPM maximum flow rate • Pressure compensating technology • Full face spray pattern Average Cost:$40

Bricor EcoFIT

• 1.25 GPM @ 50psi
• 50% solid brass and 50% chromed ABS material with a Neoprene spray plate
• Patented aeration

Average Cost: $25 Bricor EcoFIT[23] Oxygenics 630-XLF • 1.5 GPM Maximum flow rates • Patented aeration • Pressure compensating technology Average Cost:$25'

Oxygenics 630-XLF[24]

## DIY Resources

### How to determine the flow rate of your current shower head

Inspired by Paul Scheckel's "The Home Energy Diet"[25]

1. Turn on the shower how you usually would when you take a shower
2. Using a one-gallon jug and a watch with a second-hand, time how long it takes to fill the jug under the flow of your shower head.
3. Do the math to calculate your flow rate; if it takes 60 seconds, that's one gallon per minute!

GPM = 60 (number of seconds in a minute) / how many seconds it took to fill a one-gallon container

Flow Rate Calculation Table in Gallons per Minite
Number of seconds to fill Using a Quart jug Using a Gallon Jug
3 5.00 20.0
4 3.75 15.0
5 3.00 12.0
6 2.50 10.0
7 2.14 8.60
8 1.88 7.50
9 1.67 6.70
10 1.50 6.00
12 1.25 5.00
15 1.00 4.00
20 0.75 3.00
30 0.50 2.00
40 0.38 1.50
50 0.30 1.20
60 0.25 1.00

## Conclusion

As the population continues to grow and impending global climate change brings new environmental challenges, water demand will also increase in the future. Indeed, research indicates water demand is currently exceeding supply, making conservation efforts crucial if we hope to maintain a good water source. Rolston St. Hilaire (2009) of New Mexico State University asserts, "The lack of water has the potential to jeopardize our food supply, disrupt fragile ecosystems, alter alliances among constituents, and threaten our way of life."[26] Thus, to avoid the possibly catastrophic consequences of squandering our much-needed water supply, the public must assume an active role in conservation. Helen Ingram (2009) of the University of California-Irvine reports that following extensive studies on local, regional, and global water use, a team of scientists concluded that, "A crucial part of the path to water conservation involves paying close attention to the dimensions and scales that define how people interact with and understand water."[27]

## References

1. Ball, Jeffrey. "Under Pressure: Bathers Duck Weak Shower Heads; Water Shortages Spur Restrictions and Low-Flow Designs but Some Aren't Willing to Sacrifice and Skirt the Rules." The Wall Street Journal, Eastern Ed. Vol. 254 Issue 115 pA18.
3. https://www.epa.gov/watersense
4. https://www.epa.gov/watersense/watersense-partners
5. Benazzi, Robert. "Water Conservation Protocols." Buildings 103 no. 10 Oct. 2009.
6. Johnson, David, and Kim Master. Green Remodeling: Changing the World One Room at a Time. New Society Publishers. Gabriola Island, Canada. 2004.
7. http://www.flickr.com/photos/jonathanziapour/2613204502/
8. http://web.archive.org/web/20100713160918/http://www.clallam.net/environment/assets/applets/W18d1_Appendix2-D-WaterConservationMeasures.pdf
9. http://frugalmechanic.com/auto-parts/weiand/cooling-system-water-pump
10. http://www.eco-builder.co.uk/category/water-saving-devices/
11. http://wordnetweb.princeton.edu/perl/webwn?s=aerate
13. http://www.physorg.com/news82299918.html
14. http://www.peteducation.com/article.cfm?c=16+2148&aid=2825