By Mark Lawinger, Senior Product Line Manager for Flushometers and Fixtures, Sloan
You have probably heard about “the five Ps:” Proper planning prevents poor performance. This concept is particularly important when embarking on a commercial retrofit project to reduce water consumption.
Whether it is to gain LEED points, meet regulatory requirements, save on utility costs, or contribute to a larger green initiative, there are multiple benefits to upgrading outdated plumbing fittings and fixtures. Thanks to advancements in commercial plumbing technology today’s commercial restrooms use only a fraction of the water compared with systems from decades past.
It can be tempting to simply specify new high-efficiency equipment, calculate the gallons saved per fixture, count the fixtures, and multiply to get the expected water savings. In a perfect world, that is all that would be needed to get started. But a lack of planning can cause problems. The best way to avoid unexpected results is to thoroughly investigate the existing plumbing system before specifying any components or making calculations.
Unlike new construction, with a retrofit project, the contractor does not have every detail of the plumbing system meticulously documented in the mechanical plans. Retrofit projects mean installing new equipment with different specifications into existing—and often unknown—conditions, both upstream and downstream from the fittings and fixtures. It is important to talk to the people who know the system, such as building owners, facility managers, and maintenance personnel—anyone who knows the history of the building’s plumbing.
Step 1: Conduct the Assessment
Conducting a thorough assessment means inspecting the plumbing system and measuring as many performance variables as possible. Information should be gathered from three key areas: upstream, downstream, and at fixtures and valves.
Upstream
Pressure (static, dynamic, pressure over time)—Static pressure readings are a good starting point, but they are not the “tell-all” for the health of a system. Static pressure, working pressure, and recovery (the time for the system pressure to return to the static readings) are vital to determining a system’s response and capacity. Very high static readings (above 80 psi) can be a warning sign, pointing to failing pressure-reducing valves (PRVs) or, much more concerning, a volume or capacity problem.
Piping diameter—It would seem logical that by taking the fixtures from 3.5 gallons per flush (gpf) to 1.28 gpf, the demand on a water supply system would be reduced. However, the opposite is true: The same amount of waste must be evacuated through a new fixture with half the water volume—in many instances, a smaller water spot and trapway.
Plumbing layout and number of fixtures being fed by each line—Is the building plumbed correctly with main lines? Are all branch lines sized correctly to meet the demands of the fixture counts?
Past history of building expansion—Have there been additions to the building’s footprint without increasing the water supply system capacity?
Water quality—Water quality is an often overlooked factor in water savings analysis. In piston valves, high amounts of sediment or sand shorten the life by wearing down the lip seal. This results in a shorter flush cycle, making it necessary to flush twice to clear the bowl. Diaphragms with unprotected bypass holes may experience run-ons if the sediment clogs the bypass, or they may develop much greater flush volumes if the bypass is partially blocked.
Fixtures and Valves
Document the manufacturer and model number of all the equipment to be replaced and assess the age and condition of the equipment. Gather the following information:
- Flush volume rating
- Any signs of leaking from fitting or fixture
- Last maintenance or maintenance schedule
Downstream
Depending on the age of the system, the original waste line carry calculations were probably based on 4.5 gpf. Through attrition, the original fixtures may have been replaced to 3.5 gpf or 1.6 gpf. Further reducing the water to 1.28 gpf could result in downstream problems. Here are some red flags:
- Problem or chronic line blockages or toilet backups
- Poor pipe conditions, including corrosion, leaks, and cracks
- Long horizontal waste line runs
- Improper waste line slope
- Signs posted in restrooms warning what not to flush down fixtures
Step 2: Determine the Feasible Options
Once the assessment is complete, a more accurate picture of the available (and practical) options for the retrofit can be determined. Depending on the number of red flags raised, the scope of the project may need to be adjusted, taking into account the expected cost and anticipated water savings for each option. Possible upgrade options include the following:
- Minor upgrade: Change out diaphragm kits.
- Intermediate upgrade: Change out flushometers.
- Moderate upgrade: Change out flushometers and fixtures.
- Major upgrade: Change out the entire plumbing system.
Step 3: Prepare the Estimate
With the assessment complete, the most appropriate option can be selected and quoted to the customer. Then, it is time to start procuring materials.
Step 4: Test the Solution
Testing the planned savings strategy on one or two fixtures or restrooms before converting the entire building can provide valuable insights into the expected performance of the system. Be sure to test the most extreme cases first (i.e., fixtures farthest from the water supply or situations with the greatest demand).
Step 5: Expand the Upgrade to the Entire Building
If the test installation performs as expected, go forward with the project.
Commercial water savings projects are not only financially smart, they are environmentally responsible—and in some municipalities, legally mandated. Today’s technology can help achieve real and meaningful savings, but the reduced water volume can have unintended consequences if the plumbing system is not capable of adapting to the lower flow. With foresight and planning, risks can be avoided and water savings goals achieved.
Watch this webinar to learn more about using Sloan products for commercial water conservation projects: https://www.sloan.com/resources/education/webinars/water-conservation-and-sloan-commercial-restroom-products
Use Sloan’s interactive map to learn about municipal rebates for water-saving products: https://www.sloan.com/sustainability/tools/product-rebate-finder
For more information, visit www.sloan.com. MCAA thanks SLOAN for being an MCAA sponsor.
