| Americans consume almost 4.8 billion gallons of water daily by flushing toilets and urinals. In a business office setting, toilet water usage alone can account for approximately one-third of all water used. A number of water efficiency options exist for toilets in most facilities constructed before 1994 that have not been renovated recently.The three major types of toilets include gravity flush, flush valve and pressurized tank type. Dual flush toilets also are gaining in market share. Pre-1977 gravity toilets will consume five to seven gallons per flush. Pre-1977 flush valve toilets use 4.5 to 5.0 gallons per flush. Gravity and flush valve style toilets manufactured between 1977 and the mid-1990s mostly use 3.5 gallons per flush. High efficiency toilets began appearing on the market in the mid 2000s. HETs use less than 1.3 gallons per flush. |
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Code Compliant 1.6 Gallons Per Flush Toilet
In the 1990s, toilet manufacturers introduced ultra-low-flush toilets that use 1.6 gallons per flush. Federal regulations require that all toilets manufactured after Jan. 1, 1994, consume no more than 1.6 gpf. Some of the original ULF models encountered performance problems, but more recent models have improved designs and performance. |
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High-Efficiency Toilets
The most efficient commercial toilet on the market is the high efficiency toilet. HETs use less than 1.28 gallons per flush. This performance is achieved by an improved flush and fixture design. Early user satisfaction studies show positive customer feedback. HETs combine high efficiency with advanced design for high performance. Manufacturers are striving to avoid the issues experienced with some of the first-generation 1.6 gpf models. Since 2003, most manufacturers have offered HET toilets. In 2007, the EPA WaterSense program began performance qualifying HETs and other water fixtures with the WaterSense label.
An HET replacement program offers the highest water savings potential. Facility owners should be aware of factors that will make the HET or ULF toilet replacement program successful HETs are available in the following configurations:
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Single-flush, tank-type gravity toilets
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Dual-flush, tank-type gravity toilets
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Dual-flush, tank-type flush valve toilets
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Tank-type pressure-assisted toilets
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Battery-powered, sensor-activated dualflush toilets |
Gravity Flush Toilets
Gravity flush toilets are the most common of all toilets. Gravity flush toilets most likely are found in medium- to light-use business applications. Water efficiency options for gravity flush toilets include improved maintenance, retrofit and replacement options.
Retrofit
Retrofit options of gravity flush systems are most effective on units that consume more than 3.5 gpf (pre-1980s models). For toilets that consume 3.5 gpf or less, some retrofit options may hamper toilet performance or increase maintenance cost. Most retrofit options are available for less than $20.
Displacement devices, including bags or bottles, can reduce water flow by approximately 0.75 gpf. They function by displacing flush water stored in the tank. The devices are inexpensive and easy to install, but do require regular maintenance. Bricks or other friable objects should never be used as displacement devices because granular contaminants can prevent proper closure of the flapper and damage flow valves. Toilet dams are flexible inserts placed in a toilet tank to keep 0.5 to 1 gallon out of each flush cycle. Dams will last five to six years. A plumber should be consulted before installing such devices. Early closure flapper valves replace the existing flush valve in the tank. These devices are adjustable to optimize performance and can save 0.5 to 2 gpf. Early closing flappers are inexpensive and usually can be installed in 10 to 15 minutes, barring other problems with the toilet’s mechanisms. Dual-flush adapters allow users to use a standard flush for solids removal or a modified smaller flush for liquid and paper. Dual-flush adapters have been more popular in Europe than the United States. Dual-flush adapters can save between 0.6 to 1.2 gpf. For this retrofit option, facility managers should provide user instructions about the proper use of these dual-flush systems.
Replacements
Replacing older commodes with HET or 1.6 gpf models will provide the most water savings. Most HET or 1.6-gpf replacements will offer a payback period of less than three years. Facilities may achieve quicker payback in these situations:
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Experience high water and/or sewer costs.
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Have a relatively high number of users per toilet.
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Currently use high water-consuming (5 to 7 gpf) toilets. |
Flush Valve Toilets
Flush valve, or flushometer, toilets use water line pressure to flush waste into the sanitary sewer system. They consist of a valve and a toilet bowl fixture. Most commercial/industrial facilities use flush valve toilets, especially in higher-use areas.
Retrofits: An economical water-saving opportunity exists to retrofit 1.6 gpf flush valve toilets with a dual flush valve. The valve is actuated upwards to flush liquid waste and downward to flush solids. These valves cost as little as $40 and offer a 20 percent water savings with a simple payback in three to four years in an office setting. For 3.5 gpf flush valve toilets, valve inserts are available that can reduce flush volumes by 0.5 to 1 gpf. Some of these devices consist of plastic orifices, perforated with holes in a wheel and spoke pattern. Others actually replace the existing valve mechanisms of a 5 gpf unit with a 3.5 gpf valve without changing the toilet bowl fixture. Do not retrofit ultra-low valves (1.6 gpf) without changing a fixture bowl.
Replacements: Replacing inefficient units with a HET or ultra low (1.6 gpf) flush valve mechanism and toilet bowl will result in the maximum water savings. It is important to note that both the low-flow valves and bowls should be replaced simultaneously. A 1.6 gpf valve must be used with an appropriately designed 1.6 gpf bowl, or the unit will not perform adequately. |
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Pressurized Tanks System Toilets
An effective commercially-designed toilet currently on the market is the pressurized tank toilet. These units perform very well at removing waste, but also are more costly. These toilets use water line pressure to compress air in a specially sealed tank in the toilet. When flushed, the compressed air greatly increases the flush water force. Noise was a complaint with early models, but present models are markedly quieter. |
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Composting Toilets
Where sewers or septic tanks are not available, composting and incinerating toilets are available. Before purchasing any of these toilets, make sure building inspection programs can approve such toilet systems. |
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Urinals
It is estimated that about 80 percent of America’s 12 million urinals are old and inefficient. The typical water consumption for older urinals is 2 to 3 gpf. Current federal standards require all urinals to use no more than 1 gpf. Urinals can have a flushometer value or water tanks for both washdown and trough urinals. |
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High-Efficiency Urinals
Newer models that can significantly reduce water consumption are now available. A high efficiency urinal is now defined as a urinal fixture with a flush volume of 0.5 gpf or less, including waterless units. Some manufacturers are offering urinals that use as little as one pint (0.125 gallon) per flush. Flush mechanisms for these urinals include standard manual flushometer units, handsfree hard-wired sensor-operated units, and hands-free-battery-powered sensor-operated units. |
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Waterless Urinals
Waterless urinals can save time and money and conserve significant amounts of water. The waterless urinal involves a vitreous china or stainless steel fixture and a replaceable oil-filled cartridge that traps odors. Progressive public facilities, businesses and new high-performance LEED buildings have been demonstrating this technology in North Carolina. Waterless systems are more economical to purchase and install than flush urinals because they have no flushing mechanism. Waterless urinals offer the savings of flush water and sewer charges, but these operational savings are balanced with the cost of cartridges for the drain which typically are replaced every 7,000 uses. Cleaning crews must have training on proper cleaning and cartridge replacement procedures for units to function as designed. Waterless urinals are not without controversy, and further research is needed to better understand long-range impact and wide application of their use. Retrofit applications which were not installed perfectly vertical have been problematic. Pilot trials are suggested. |
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Washout and Washdown Urinals
Some models can be retrofitted to use less water per flush by replacing a part in the flush valve or float levels in tanks. Make sure any retrofit will continue to allow adequate removal of liquid waste. Again, bowls and flush valves need to be compatible in design use to function properly. Installing new models that use 1.0 gpf can achieve the maximum water savings for urinals. |
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| Information Courtesy of: “Water Efficiency Manual for Commercial, Industrial and Institutional Facilities” researched by the N.C. Department of Environment and Natural Resources, Division of Pollution Prevention and Enviornmental Assistance, Division of Water Resources, Land-of-Sky Regional Council, Waste Reduction Partners |
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