Faucets have not been a primary focus of water efficiency advocates, given that the Energy Policy Act (EPAct) of 1992 and subsequent EPAct legislation have limited faucet flows to 2.2-gpm (at 60 psi). (NOTE: In public restrooms, the flow rate on faucets is limited by standards and codes to 0.5-gpm.) It is only now that serious attention (by the U.S. EPA's WaterSense product labeling program) is again being given to residential faucets and the possible new opportunities for further efficiencies.
|SPECIAL NOTE:The reduction of residential bathroom faucet flows below the 2.2-gpm maximum will cause the wait times for hot water to increase. As an example, with an assumed wait time of 30 seconds for hot water arriving through a 2.2-gpm faucet, the replacement of the aerator in that faucet with one flowing at 1.1-gpm will generally double the wait time for hot water to 1 minute. Therefore, any reductions proposed in the bathroom faucet flow rate must be accompanied by an evaluation of the effect upon the end-user and their attitudes towards the delivery of hot water when they want or expect it. Go here for further detailed information on Residential Hot Water Distribution.
In the past several years, the commercial side of faucets has been a topic of conversation, if not research. That conversation has asked the question…
Do sensor-activated commercial faucets save water?
Most water efficiency practitioners readily acknowledge that sensor-operated flush valves (for commercial toilet and urinal fixtures) save no water. In fact, they would quickly say that these devices waste water by flushing more frequently than necessary! But, what about faucets?
Millenium Dome Report on Water Efficiency-“Watercycle” (2002)
Thames Water’s “Watercycle” project at the Millennium Dome in London was one of the largest in-building recycling schemes in Europe, designed to supply up to 130,000 gallons per day of reclaimed water for WC and urinal flushing. It catered to over 6 million visitors in the year 2000. Overall, 55% of the water demand at the Dome was met by reclaimed water. The Dome was also the site of one of the most comprehensive studies ever carried out of water conservation in a public environment, evaluating a range of water efficient appliances and researching visitor perceptions of reclaimed water.
Of particular interest is Figure 6 in the report which shows washroom water use for handwashing and compares infrared sensor-operated faucets with “push top” (cycling) faucets and conventional swivel top faucets. It confirms that infrared sensors on the faucets create a waste of water when compared to conventional fixtures:
- Millenium Dome Summary Report (PDF)
Another study that included comparisons between manually operated faucets with sensor-activated faucets was published in 2002 by ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc.). While not the main focus of the study, titled “Field Test of a Photovoltaic Water Heater”, Tables 3 and 4 provide data needed for the comparisons.
- Sensor Operated Faucets - ASHRAE (PDF)
"Hands-Free" Faucet Valves
Two manufacturers have introduced devices that enable the end-user (home or office) to open and close a faucet valve “hands-free”. Go to these websites for more information on the Pedal Valve: