Performance Gains Make Efficiency Choices Easier

It’s not a question of should a facility have high-efficiency Flushometers but of which types are right based on building age, drain conditions and other factors.

By Rick Nortier

Professionals are showing greater willingness to use high-efficiency Flushometers as long as they can be assured that these systems meet third-party standards for high performance — and their high expectations. The technologies behind today’s Flushometers have come a long way over the past few decades, and the high-efficiency commercial systems rival what’s happening on the residential side of the market in terms of increasing performance while decreasing water usage.

Yet, there are many factors to consider beyond just technology before deciding which system is right for a particular facility. The options are many, and the EPA WaterSense® program is a good place to start when deciding which factors will pertain to the facility.

For a High-Efficiency Toilet (HET) to meet the requirements of ASME A.112.19.2, it must flush at a maximum of 1.28 gpf. HETs must also successfully remove at least 350 grams of waste, according to MaP test score guidelines, to adhere to the EPA’s WaterSense specifications for HETs. Flushing at 1.28 gpf or less, HETs use at least 20% less water than the conventional 1.6 gpf water closet and can offer substantial water reductions, especially when replacing older water closets using 3.5 gpf or more. Dual-flush Flushometers, which have an aggregate flush volume below the 1.28 gpf threshold when accounting for an average 2:1 usage ratio of two reduced water-consumption flushes at 1.1 gpf for every one standard 1.6 gpf flush, are HETs.

A High-Efficiency Urinal (HEU) must have a maximum flush volume that is equal to or less than 0.5 gpf, which is at least 50% less than the 1.0 gpf maximum for standard urinals. Although performance tests such as MaP are not currently conducted on HEUs, the WaterSense specification states that HEUs have to “…ensure both sustainable, efficient water use and a high level of user satisfaction with flushing performance.”

The best case scenario is achieved when the Flushometer and fixture are optimized to work together in order to guarantee the intended flush volume is maintained while fully evacuating the fixture. Flushometers and vitreous china fixtures are available both separately and as engineered combinations from many manufacturers, and professionals need to choose which approach best suits their needs. It’s not all about cost; performance is really the key issue, and professionals need to do their homework.
The research and testing division of the International Association of Plumbing and Mechanical Officials Professionals (IAPMO), for instance, tests and certifies plumbing products to ensure they are in compliance with plumbing codes and standards. The IAPMO Web site, among others, lists plumbing fixtures and fittings that have passed its testing (see the product listings at www.iapmo.org). Such listings give insight into mix-and-match or packaged combination decisions.

New construction has the advantage of starting with the latest flushing technologies, as well as system design practices. HETs and HEUs are natural choices for both performance and water savings.
Plumbing retrofit and renovation project choices differ for existing buildings, however. Facility owners who want to reduce water consumption by moving to HETs, yet still have the older 3.5 gpf water closets, would be well advised to change out their fixtures and fittings. In that case, the decision comes down to: Would a 1.28 gpf or a 1.6/1.1 gpf dual-flush system work best? When making plumbing upgrades, consider both the age of the building and the condition of the drains.

When a facility switches from 3.5 gpf to 1.6 gpf water closets, it still experiences similar peak flow rate demand on its system. For slightly shorter durations, a system may need to supply a higher flow rate to initiate siphonic action in the bowl. Just because the flush volume is reduced, it does not mean that the peak flow rate is reduced. To the contrary, it is even more important to have a strong water supply, because the same amount of energy is needed to move waste adequately with less water.
On the downstream, consider the drains: For an older building that was designed for 3.5 gpf water closets and has been in operation for many years, it may be advisable to video the drains. A diagnostic camera inspection can offer a clear understanding of drain conditions before determining what would work best. Possible obstructions, the distance to the stack and even the pitch can be evaluated, ensuring no “surprises” after the upgrade. Evacuating the fixture does not mean much if the waste cannot be efficiently moved through the drain system.

Electronic options

Facilities can either install a complete, new sensor-operated Flushometer or convert an existing manual Flushometer to sensor operation with a retrofit sensor kit. The decision between installing a new sensor-operated Flushometer or converting an existing manual Flushometer to electronic operation depends on the project at hand. For new construction, or old restrooms with aesthetically challenged fittings (such as chrome worn away from years of abuse or harsh cleaning), it is best to specify all new electronic Flushometers. The latest generation of these products has superior optics that better identify the user, resulting in fewer false activations.

Advancements in electronics have allowed manufacturers to improve their sensing and logic algorithms to offer users more benefits, including options such as deferred flushing, which flushes urinals at preset timed intervals instead of after every user. This setting saves water and allows for faster turnaround when there are lines of men waiting for urinals, which is useful in stadiums, theaters and other facilities that expect heavy traffic for brief periods of time. Another feature, sentinel flush, refreshes the fixture and trap seal by automatically flushing after a preset period of non-use.

Many existing manual Flushometers can be upgraded to electronic operation using retrofit kits. Retrofits are typically battery-powered units, which make them ideal for restrooms where main AC wiring is inaccessible or cost-prohibitive. Solar-powered Flushometers, which draw energy from any natural or artificial light source to power the sensor, offer the benefit of battery-powered installation with the additional advantage of significantly extending battery life through the solar panel.

For restrooms that have accessible main AC connections, especially those in high-traffic facilities that would quickly surpass the energy lifetime of battery-powered flushing units, low voltage transformer-powered retrofit models are a good option. Transformers for complete sensor Flushometers or retrofits include plug-in and foot- or box-mount styles, which can operate multiple fittings. Some transformers can power as many as 10 water closet or urinal Flushometers. Installers should allow a minimum of 15 VA of current rating per solenoid; manufacturers can advise on proper transformer sizing based on the number of fittings.

Dual-Flush: Less Water, More Savings

Dual-flush Flushometers are rising in popularity, partly because they easily meet HET performance standards as proven by independent testing. The public is increasingly interested in doing its part for the environment, and building owners largely support that — as long as it’s economically feasible.
Dual-flush functionality for water closets is a win-win: Restroom users can choose a reduced or regular flush, depending on solid or liquid waste, and the reduction in water consumption results in lower water and wastewater utility bills. Dual-flush functionality typically saves about a half-gallon of water in its reduced flush cycle, and can be manually or electronically activated.

Once it has been decided that dual-flush functionality is right for the restrooms, the fixture choice then becomes manual or electronic. In smaller buildings, it may be more advantageous to install manual dual-flush Flushometers in restrooms because they have a regular set of users. These users are more familiar with (and conscientious about) the facility, which means they are more likely to learn how to manually operate a dual-flush Flushometer to its full potential. In a large commercial building with a transient population, however, it is more difficult to train users on proper fixture usage. For these restrooms, electronic dual-flush Flushometers, which automatically initiate the appropriate flush cycle depending on the amount of time the user remains in the sensor range, are ideal.

Dual-flush functionality can be purchased as separate retrofit conversion kits or as part of complete Flushometer systems. A manual retrofit kit consists of a dual-flush handle that replaces a regular flush handle. An electronic kit includes an electronic assembly body that installs in place of the existing valve body.

Professionals should also determine the suitability of using dual-flush Flushometers with certain water closets. Bowls must be able to handle greater minimum/maximum extremes with dual flush, and not all vitreous china models are meant to do the job.

Taking advantage of water-efficient plumbing systems is one of the best ways to substantially reduce water usage in all kinds of commercial facilities. Consider which options are appropriate for certain projects, and give today’s high-efficiency plumbing solutions a fair chance.

Rick Nortier is the OPTIMA® product manager for Sloan Valve Company.