All toilets and most showerheads today meet the federal water-efficiency standards, but not all of these products perform satisfactorily. With toilets and showerheads, we include products that meet or exceed WaterSense standards, which includes performance requirements—although we go beyond WaterSense where there are issues not adequately addressed by the program. We also look for other products that conserve potable water, such as rainwater catchment and graywater recovery and reuse systems.
The Evolve Ladybug showerhead adapter and Roadrunner showerhead feature ShowerStart technology that reduces water and energy waste while users wait for hot water. The Evolve adapter is installed between the shower stem and the showerhead. When the water temperature at the valve reaches 95°F a wax-activated valve reduces the flow to a trickle. To restart the full flow, the user twists the knob on the unit or pulls an attached cord. After each use, the showerhead adapter resets. The Ladybug 1/2" adapter has chrome finish and is compatible with most showerheads. Other features include solid brass construction, anti-lime protection, and an integrated debris screen. The Roadrunner showerhead (shown here) includes the ShowerStart shut-off valve and has a water-conserving flow rate of 1.5 gpm; it is available in chrome and brushed nickel.
Showers account for about 17% of all indoor residential water use, according to the EPA. Inefficient showerheads increase water and energy use, but some newer low-flow units have been faulted for delivering poor performance, leading people to spend more time in the shower, or remove the showerhead and replace it with an older, much higher-flow showerhead.
WaterSense has developed a specification that includes water efficiency, spray force, and spray coverage criteria. The first criterion is designed to reduce water use; the last two are aimed at maintaining a standard for superior shower performance, even as less water is being used. After doing field research in 2008, WaterSense developed tests that measure performance in spray force and spray coverage. Not directly included in the WaterSense criteria is “wetting performance” (though spray coverage could be a proxy for that) and “heat retention,” which is a function of droplet size. Showerheads that atomize water into very small droplets cool off very quickly, though atomizing showerheads may or may not satisfy the “spray force” requirement in WaterSense.
GreenSpec lists showerheads that use no more than 1.75 gallons per minute (gpm)—below WaterSense’s limit of 2 gpm—and are WaterSense labeled to address spray force and coverage
Shower satisfaction is a complex and highly variable user experience, much like thermal comfort. Including the spray force and coverage criteria is a good start, but look for additional or improved engineering and metrics as this field matures.
WEc1: Water Use Reduction
WEc2: Innovative Wastewater Technologies
WEc3: Water Use Reduction
WEc3.1-3.2: Water Use Reduction
WEp1: Water Use Reduction—20% Reduction
WEp1: Minimum Indoor Plumbing Fixture and Fitting Efficiency
WEp1: Water Use Reduction
Ratings and Commentary