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PERC begins drainline carry research study

CHICAGO — In January the Plumbing Efficiency Research Coalition (PERC) is undertaking a research study on building drainline performance that will analyze the potential for blockages resulting from the use of reduced flow water closets in commercial buildings and evaluate the use of higher volume flush valve discharges at intermittent intervals as a way to effectively clear drainlines. The research will be done at an American Standard testing facility under the supervision of PERC.

According to Charles R. White, PERC member and vice president of technical and code services at Plumbing-Heating-Cooling Contractors — National Association, it is important this study is done because the industry will gain practical knowledge of efficient flow applications.

“This knowledge can be applied to every day installations to provide optimum operations,” said White. “Secondly, no one wants systems that are problematic or have a reputation as being trouble. Many jokes have been made in the past about reduced flow or low flow fixtures. While the industry does not want to be the target of nightly comics, the truth is water conservation is vital in some areas and becoming more and more important across the nation. The PERC study will allow high-efficiency fixtures to be applied reliably, saving water resources, and not be late night comedic fodder. Ultimately the study will lead to high performance systems that continue the long history of protecting the health and safety of the public.”

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“It seems that every plumber has an opinion on this issue already, but there is no definitive data one way or the other,” said Mary Ann Dickinson, PERC member and president and CEO of the Alliance for Water Efficiency. “That is why the Alliance for Water Efficiency as well as the other members of the Plumbing Efficiency Research Coalition are trying to assemble real data.”

According to PERC’s Test Plan Proposal to Investigate Drainline Transport in Buildings, many plumbing experts are concerned that there is a “tipping point” where a significant number of sanitary waste systems will be adversely affected by drainline transport problems, especially in larger commercial systems with long horizontal runs to the sewer. And to further raise concerns in North America, drainline transport problems in Europe and Australia have been reported.

“It has been said, ‘Those who do not study history are destined to repeat it,’” said White. “Australia has faced water shortage issues and addressed them with innovative solutions. Being alert to situations globally should allow the industry to be proactive in future applications of technology. If it is known that problems have arisen in certain instances, the industry should rightly try to model and test situations and solutions to determine the best approach to these problems.”

Australia is many years ahead of the USA in terms of market transition towards high-efficiency water conserving plumbing fixtures and appliances due to the extended drought they have experienced, said Pete DeMarco, PERC member and director of special programs at the IAPMO Group, therefore, it’s not surprising to see failures in building drains occurring there.

“What we need to understand is the degree to which reduced toilet discharges diminish the transport of solid waste in drains and how important those reductions are compared to other system variables such as slope and toilet design and what can be done to remedy problems if they do occur,” said DeMarco.“The PERC test plan will not only investigate the importance of those variables, but will also shed light on how those variables inter-relate. As the test plan discusses, it will also investigate if periodic surges of water into a building drain can be considered as a low cost remedy where problems arise.”

The research will allow PERC to issue design recommendations regarding the transport potential of single event, high volume clear water surges, allowing the use of high-efficiency fixtures in long drainline commercial installations and realizing overall water conserving efficiencies, according to the Test Plan Proposal, plus, the research will determine the significance of toilet design as it pertains to multi-flush, real-world drainline transport potential.

“We want to generally determine whether there is a risk of clogging or backups in long drainage runs, and under what circumstances,” said Shawn Martin, director of industry relations of the Intl. Code Council, Plumbing Mechanical and Fuel Gas Group. “If there are issues, we will be investigating design changes that can be made to mitigate the risks of clogging with low-flow water closets before adding other measures such as ‘clearing flushes.’ ”

Barbara C. Higgens, PERC member and executive director of Plumbing Manufacturers Intl., said that the key to achieving water efficiency goes beyond simply cutting back flow rates.

“Water efficiency means doing the same job as well or better with less water, while protecting public health and safety,” added Higgens. “The PERC research is intended to answer important questions about product performance and design considerations at lower flow rates. Once the research is complete, product/water efficiency questions will be able to be answered with facts and research data, not anecdotes. PMI advocates the importance of including manufacturers and other stakeholders in the development of new regulations/policies to ensure that the facts are on the table and to avoid unintended consequences to public health, safety and product performance.”

Research funding

To date $30,000 has been committed to the effort by various organizations, and that will allow PERC to move forward immediately, said Martin.

“Our hope is that additional funds will become available in time to avoid any delays down the road,” explained Martin. “The primary members are assessing whether they would be able to support the balance of the effort if that occurs. American Standard has, through their contributions, made available both the facilities and the materials necessary to modify their existing test fixtures to accommodate the test plan. This has reduced the cost and time required substantially and the PERC group is extremely grateful for their support.”

PERC hopes to begin reporting results in the latter part of 2012. The coalition has also identified other areas of drainline carry to be studied, pending the availability of funds to continue the work.

At this time, the study requires an additional $50,000 in funding. Any organization interested in contributing can contact Mary Ann Dickinson at [email protected].

Contributions received will be credited in the final study report. For more information concerning PERC and their related research, please contact any of the coalition members. Coalition member contacts are: Mary Ann Dickinson, [email protected], at Alliance for Water Efficiency; Jim Kendzel, [email protected], at American Society of Plumbing Engineers; Pete DeMarco, [email protected], at International Association of Plumbing & Mechanical Officials; Jay Peters, [email protected], at International Code Council; Gerry Kennedy, [email protected], at Plumbing-Heating-Cooling Contractors; and Barbara Higgens, [email protected], at Plumbing Manufacturers Intl.

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