With the green movement on the rise, homeowners are overwhelmed with tips and advice on how to conserve water and energy. Replacing the standard (2.5 gallons per minute) showerhead with a low-flow (less than 2.5 gpm) alternative is a frequently recommended way to "go green." As a result, low-flow showerheads have been evaluated and rated by reporters and consumer bloggers, and will be eligible to receive certification from the Environmental Protection Agency's WaterSense program in the near future. This information has been consumed by eco-friendly homeowners with the hope that it will guide them in their showerhead selection process. However, lost in the buzz about the attributes of low-flow showerheads is information about shower valve compatibility. Surprisingly, this is an important factor in selecting the low-flow showerhead that offers the best showering experience and, more importantly, is something that can have a dramatic effect on the safety of the showering experience.


BEHIND THE SCENES

Behind the wall in every shower or tub/shower combination is a mixing valve, which blends hot and cold water together. Recent plumbing codes require mixing valves installed in showers to be safety-type valves, which contain a mechanism that compensates for pressure disturbances that cause the outlet water temperature to fluctuate.

There are two types of safety valves installed in most showers, thermostatic valves and pressure-balancing valves. Thermostatic valves react to temperature changes in the water resulting from a disturbance in water pressure within the plumbing system. Pressure-balancing valves react instantly to the pressure disturbance within the plumbing system to maintain a safe, pre-selected water temperature.

If you have ever suffered an abrupt change in water temperature when a toilet is flushed or a washing machine cycle begins, then you have experienced thermal shock. Thermal shock is a safety concern for bathers not only because it can result in scalding, but also because bathers—more commonly—suffer slip and fall injuries as they react quickly to avoid the suddenly very cold or very hot water flowing from the showerhead.

Safety shower valves are designed to react and adjust to these disturbances in water pressure within the plumbing system and consequently maintain safe water temperatures, providing bathers a comfortable and enjoyable shower experience.

Furthermore, certified shower safety valves must adhere to a standard set forth by the American Society of Sanitary Engineers, listed as ASSE 1016—Automatic Valves for Individual Showers & Tub/Shower Combinations. Minimum test requirements within this standard mandate that safety-type valves maintain the bather's set outlet water temperature at a flow rate of 2.5 gpm.



















_{In addition to the Sereno and Winslet showerheads shown at the top of this article, Symmons Industries offers the Oxford (left) and the Three Mode (right) showerheads, both available with 1.5-, 2.0-, and 2.5-gpm flow rates.}



COMPATIBILITY IS KEY

As previously stated, safety valves work properly with a standard 2.5-gpm showerhead because they have been mandated to do so by ASSE 1016. However, the same valve may not work properly in combination with a low-flow showerhead at a flow rate less than 2.5 gpm. This is important to understand because if the valve is unable to accommodate a change in pressure—as a result of the low-flow showerhead—it may not be able to maintain safe bathing temperatures.

Until a standard is published for showerheads and valves operating at flow rates less than 2.5 gpm, consumers, designers and installers need to understand the importance of valve and showerhead compatibility. In order to ensure a safe shower experience, they should contact the valve manufacturer and verify that the flow rate of the showerhead is compatible with its shower valve.


LOOKING FORWARD

Manufacturers are working with industry organizations and standards developers to prepare standards for the safety of low-flow showerheads and valve performance. In the future, consumers will have better guidance when it comes to choosing compatible parts because manufacturers will publish in their literature and on their packaging the valve and showerhead flow rates.

So, regardless of the latest consumer report on low-flow showerheads, knowing the type of valve that is behind your shower wall could have the biggest influence on your decision in selecting a safe, as well as water- and energy-conserving, showerhead.


—Tim Kilbane is the national sales manager for Commercial Products at Symmons Industries. He has more than 35 years of plumbing experience, has been an active member of various standards committees and currently sits on the Board of Directors of the Plumbing Manufacturers Institute (PMI) where he serves as a co-chairman of its Water Temperature Device Committee.