Ensure Happy Users With High-Efficiency Plumbing

User satisfaction and efficiency are not incompatible.

WaterSense-approved faucets use no less than 0.8 gal./min. (gpm) and no more than 1.5 gpm, which is a 30% reduction over standard 2.2 gpm models.

By Mark Malatesta and C.J. Lagan, LIXIL Americas, American Standard Brands

Restrooms provide the biggest opportunity to conserve water in commercial buildings. However, property owners and facility managers can be reluctant to adopt the latest high-efficiency fixtures, given the frequent complaints that commercial restrooms can generate:

• Toilets have to be flushed twice.
• Sensor faucets are hard to activate and always run cold.
• Urinals have an odor issue.
• Shower pressure is disappointing.

The challenge is that many buildings are still using low-flow technologies from the 1990s or early 2000s that fail to meet user expectations. These first-generation, water-saving fixtures often have internal components that were not reengineered to match the reduced flow rates. With a lifespan of at least 10 yr., these outdated fixtures continue to create user skepticism and frustration.

The good news is that today’s low-flow commercial fixtures have been designed and reengineered to deliver high-performance results, including a quality user experience, water savings, and reduced maintenance. It all starts with specifying restroom fixtures with the proper commercial design and operation.

Flush With Confidence

Toilets that clog easily, cannot remove solid waste with a single flush, and leave behind unpleasant stains are a major concern to commercial maintenance teams and building owners. If users need to flush multiple times, this lack of performance not only negates any water-saving benefits, but also adds frustration and embarrassment to the user experience.

Proper fixture specification will ensure toilets and urinals have been engineered with demanding commercial use in mind. Specifiers should source commercial toilets with these features:

• WaterSense Certification. WaterSense-certified toilets use no more than 1.28 gal. per flush (gpf), which is less than the federal standard of 1.6 gpf. The WaterSense label balances conservation with performance, as the EPA standard includes “a minimum flush volume of 1.0 gpf to ensure plumbing systems have adequate flow to function effectively.” This minimum-flush value addresses concerns about sufficient drain line carry to move waste through a building.

Flush valves with a self-cleaning refill orifice deliver reliable performance by preventing clogs that cause the valve to continuously run and waste water.

• Flush Valve. Flush valves with a self-cleaning refill orifice deliver reliable performance by preventing clogs that cause the valve to continuously run and waste water. The self-cleaning refill orifice is especially beneficial for areas with poor water quality such as debris, sand, scale, or minerals from hard water. It greatly reduces maintenance, which results in a lower cost of ownership over the lifetime of the product.

In order to work properly, the refill orifice must stay unblocked so that water can flow into the upper valve chamber to pressurize and close the valve. Models with an integral wiper spring clean the refill orifice with each flush, delivering trouble-free and consistent operation over time.

• Trapway Size. A wider trapway prevents clogs and reduces service calls. Additional glazing seals the trapway to create a smooth surface that streamlines the passage of waste.

• Bowl Wash. Leftover bowl residue compromises the user experience. A good bowl wash should swirl 360 deg. around the entire surface, pushing all materials down to the trapway.

• Siphon Jet. This performance feature enhances waste removal. Water is channeled directly from the tank or flushometer to the entrance of the trapway. This jet of water then propels waste out through the trapway, where the extra push of water helps establish a siphon to remove the waste. The design is an advantage over non-siphonic flush toilets, which rely solely on a wash-down design that pushes waste through the trapway.

• Water Surface Area. The more generous the water surface area is, the less dry surface there is for materials to cling to, resulting in less maintenance and fewer odors. A larger water surface area can also minimize splashing.

• Elongated Bowls. An oval shape is better suited to adult anatomy because it provides space where it is needed most. The additional room also ensures skin does not touch porcelain when the user is in a seated position or using a wiping motion.

Finally, specifiers can ensure the best performance and the most water savings by using hydraulically matched chinaware fixtures and flush valves that have been engineered to work together. This is done by optimizing the discharge from the flush valve to meet the hydraulic requirements of the fixture.

As specifiers work to design restrooms that offer the best-possible user experience, it’s important to consider external factors that can impact performance, such as low water pressure, inadequate drain line-carry pipe slope, or extended piping within a building that does not have sufficient supplemental water flow.

When guests stay at a hotel or shower at a spa, they expect to have an exceptional experience.


Low-flow urinals can use as little as one pint/flush. A model with a flushing rim will ensure that water washes down all sides of the urinal, rinsing away any residue that may lead to stains or odors, and resulting in fewer service calls for busy facility professionals.

Water-efficient urinals should also meet ANSI/ASME A112.19.6 for flush performance. This performance standard uses a series of tests to ensure: all sides of the fixture are washed down, the water exchange rate in the trap maintains a specific dilution ratio, and the urinal uses only 1 gal. or less/flush.

The WaterSense label verifies that water-efficient urinals have not sacrificed performance. While these models use no more than 0.5 gpf and must comply with existing standards, they are also required to be “independently certified to ensure that they flush effectively and have properly functioning drain traps.”


When guests stay at a hotel or shower at a spa, they expect to have an exceptional experience. Part of the allure of showers is to feel pampered. For those on a business trip, a rewarding shower can be an energizing start or the perfect end to a long day. Few things are more disappointing to a guest than to step under a showerhead and have a weak stream of water.

Low-flow showerheads use between 1.5 to 2 gal./min. (gpm). Water conservation should not require guests to sacrifice a rejuvenating shower experience. If a low-flow showerhead is not living up to guest expectations, it might be suffering from one of these problems:

• Pressure Compensation. This essential feature ensures a constant level of water pressure despite a lower flow volume. It’s important to note that a pressure balance valve is not standard on every showerhead model. This type of valve regulates flow by applying a fixed differential pressure, which creates a uniform water-force level using less water.

• Spray Force. Separate from water pressure, spray force can make a big difference to user satisfaction. This performance attribute is so important that a minimum level of water force is required for all WaterSense-certified showerheads.

• Spray Coverage. Coverage radius is also critical to a comfortable showering experience. Users may feel like a spray width is inadequate if it is too concentrated or too diffused. WaterSense measures coverage radius in order to verify that the width distribution of a spray pattern falls within a suitable range.

* Spray Patterns. Another way to deliver a rewarding shower experience is to use low-flow models with multiple spray options. Users appreciate choice and are less likely to complain about water-saving fixtures if they can customize their spray pattern. Look for showerheads that can deliver rain shower, massage, concentrated spray, and gentle stream settings.

As with toilets, the showering experience may be connected to factors unrelated to specific fixtures or fittings. Weak water pressure can stem from a number of design and maintenance issues. One common maintenance issue is mineral deposits from calcium or lime. If not periodically cleaned, these deposits can cut off adequate water flow from shower spray holes. Even if a hard water stain is not visible on the showerhead surface, internal screens and nozzles may need to be scrubbed or soaked to restore proper flow.

Bathroom Faucets

In the specification of a low-flow faucet, several features are necessary to deliver the performance level required in commercial restrooms:

• WaterSense Certification. WaterSense-approved faucets use no less than 0.8 gpm and no more than 1.5 gpm, which is a 30% reduction over standard 2.2 gpm models. To ensure water-conserving performance, “all faucets and accessories that obtain the WaterSense label have demonstrated both water efficiency and the ability to provide ample flow.”

• Aerators. The purpose of aerators is to achieve a lower flow rate while providing a firm stream of water for users. Three aerator styles are available: standard aerated (uses a small mesh screen to force air into the stream), spray (creates a pattern like a showerhead), and laminar (produces a solid stream).

• Ceramic-Disc Valve Cartridge. Most faucet valves use ceramic-disc cartridges, instead of rubber washers, to start and stop the flow of water. Ceramic discs are much tougher and better equipped to deal with extreme temperatures and can last for years without needing repairs or replacing. The cartridge protects valve life because the ceramic discs are resistant to sand, rust, and hard-water conditions.

• Sensor Protection. Some hands-free or motion-activated faucets are factory set for a maximum flow of 0.09 gal./activation. These metering faucets automatically shut off water at the end of the cycle to reduce consumption and should require little maintenance for the sensor itself. It is critical that these metering faucets include an in-line filter, which keeps the solenoid valve clean. By preventing drips and leaks, it ensures better reliability. Some models also contain a wiper spring that reduces clogs and run-ons.

• Battery Life. Frequent battery outages can undermine the efficacy of automatic low-flow faucets. A standard battery life is only 3 to 4 yr. Batteries that can operate for 5 to 10 yr. ensure continuous water savings with lower maintenance.

Last but not least, an issue that can affect the perceived quality of flow rates is hot-water supply. Users may experience a delay when using hot water and feel reluctant to wash their hands in cold water. In the absence of a closed-loop plumbing system, building owners may need to consider insulating pipes or installing a point-of-use, electric heat booster.

Water Shortages

Water conservation is a pressing concern for many commercial properties. In the U.S. alone, as many as 40 states will face water shortages by 2024. Because offices, hospitals, schools, and hotels are large consumers of water, it is important to switch to low-flow fixtures to leverage the greatest volume of savings.

The Energy Information Administration (EIA), Washington (eia.gov), used data from the most recent Commercial Buildings Energy Consumption Survey (CBECS) to estimate that, in the United States, there are approximately 46,000 commercial buildings greater than 200,000 sq. ft. that use 980 million gal. of water each day.

This level represents an estimated 2.3% of the total public water supply in the United States. On average, these buildings used 7.9 million gal./building, 20 gal./sq. ft., and 18,400 gal./worker in 2012. On a daily basis, they used an average of 22,000 gal./building, 55.6 gal./thousand square feet, and 50.1 gal./worker.

Rising utility costs are another reason to prioritize water savings. A report by the Office of Energy Efficiency and Renewable Energy, Washington (energy.gov), calculated an annual price escalation rate, using pricing from more than 60 water utilities and 40 wastewater plants. From 2008 to 2016, the average water rates increased by nearly 40%, and the average wastewater rates rose by 24%. This translates into a 4.1% annual price escalation rate for water and 3.3% increase for wastewater for building owners.

CALGreen Building Code

The 2016 California Green Building Standards Code, known as CALGreen, is the first statewide regulation of its kind. The comprehensive code “was developed to reduce GHG [greenhouse gas emissions] from buildings; promote environmentally responsible, cost-effective, healthier places to live and work; reduce energy and water consumption; and respond to the environmental directives of the administration.”

The intent of mandatory measures for water efficiency is to conserve potable water in new or renovated buildings. The code further reasons that reducing water consumption “also results in decreasing the amount of energy needed to transport, process, and treat water, thereby contributing to a reduction of greenhouse gas emissions.”

In projects larger than 50,000 sq. ft., including tenant spaces that consume more than 100 gal./day, the state code defines maximum allowable flow rates for the following plumbing fixtures and fittings:

• Water Closets. The effective flush volume of all water closets shall not exceed 1.28 gpf and be WaterSense certified.

• Urinals. The effective flush volume of wall-mounted urinals shall not exceed 0.125 gpf and floor-mounted urinals shall not exceed 0.5 gpf.

• Nonresidential Lavatory Faucets. Lavatory faucets shall have a maximum flow rate of no more than 0.5 gpm at 60 psi (pounds per square inch).

• Showerheads. A single or hand-held showerhead shall have a maximum flow rate of no more than 2.0 gpm at 80 psi and carry the WaterSense label.

Federal regulations stipulate a maximum flow rate for plumbing fixtures. By choosing a low-flow model, additional savings between 30% to 87% can be captured.

The Importance of MaP Scoring

Maximum Performance (MaP) is a voluntary testing standard that verifies how many grams of solid waste a toilet can completely remove in a single flush. This independent program evaluates the flushing power of models to 1.6 gpf (gal./flush). The test starts with one 50-gram (g) specimen formed into a cylinder at a fixed length and diameter along with four crumbled handfuls of toilet paper. Its purpose is to determine at what point the material will clog, plug, or fail to restore the trap seal after flushing.

Toilet model maximum performance (MaP) level is identified as the maximum media loading (in discrete increments expressed in grams) at which a toilet model successfully clears all test media from the fixture in at least four of five attempts when cased media is used; and in at least two of three attempts when uncased media is used.

The MaP score is assigned at the last mass interval that the toilet successfully extracted 350 g, 400 g, 500 g, 600 g, 800 g, or 1,000 g. (The latter is just more than 2 lb. of waste.) A separate MaP Premium Rating is awarded to all single-flush models that meet the 600 g-or-above level and have a rated flush volume of 1.1 gpf or lower.

Building owners should look for toilets MaP rated 600 g or higher for consistent performance.

Mark Malatesta is a senior product compliance engineer at LIXIL Americas, American Standard Brands, Piscataway, NJ (americanstandard-us.com), where he oversees product testing, product certifications, and financial management of the certification process for the plumbing fittings category.

C.J. Lagan is a senior manager, Testing and Compliance, Fixtures for LIXIL Americas, American Standard Brands, overseeing product compliance, new-product testing, and user-guide creation for the plumbing fixtures category.

Plumbing Efficiency Research Coalition

Lixil Water Technology

Information on American Standard Brands

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