Effective water management
is designed to reduce water consumption without compromising the
performance of equipment and fixtures. Using water more
efficiently reduces pressure on sometimes-limited water
resources, energy loads and chemicals used for water and
wastewater treatment, and, to the extent that the use of hot
water is reduced, increases energy savings.
Automated controls for faucets, toilets, and
urinals also help address occupants’ concerns about disease
transmission via contact with bathroom surfaces and fixtures.
They can also reduce water consumption.
According to the Dept. of Energy’s Office of Energy Efficiency
and Renewable Energy, these controls are rapidly gaining
popularity in all types of commercial and institutional
facilities, though the driver is more about hygiene rather than
water or energy savings.
Electronic controls can be installed with new
plumbing fixtures or retrofitted onto many types of existing
fixtures. Potential water savings are greater with retrofits
because current fixtures generally do not meet
water-conservation standards unless they are upgraded as part of
the retrofit.
Though water savings depend greatly on the type
of facility and the particular controls used, some facilities
report a 70 percent savings.
This type of on-demand system can also produce
proportional savings in water heating (for faucets) and sewage
treatment.
Electronic controls for plumbing fixtures
usually function by transmitting a continuous beam of infrared
(IR) light.
With faucet controls, when a user interrupts
this IR beam, a solenoid is activated, turning on the water
flow. Dual-beam IR sensors or multi-spectrum sensors are
generally recommended because they perform better for users with
dark skin.
With toilets and urinals, the flush is actuated
when the user moves away and the IR beam is no longer blocked.
The cost of automated-control fixtures is quite high.
Some brands of no-hands faucets are equipped
with timers to defeat attempts to alter their operation or to
provide a maximum on-cycle—usually 30 seconds.
Depending on the faucet, a
10-second hand-wash typical of an electronic unit will consume
as little as 1-1/3 cups (0.3 liters) of water. A 10-second cycle
is required as a minimum by the Americans with Disabilities Act.
Choose the lowest-flow faucet valves available—typically 0.5 gpm
(1.9 liters per minute).
Electronic controls can also be used for other
purposes in restrooms. Sensor operated hand dryers are very
hygienic and save energy (compared with conventional electric
hand dryers) by automatically shutting off when the user steps
away. Soap dispensers can be electronically controlled.
Electronic door openers can be employed to
further reduce contact with bathroom surfaces. Even showers are
now sometimes being controlled with electronic sensors— for
example, in prisons and military barracks.
Electronic fixtures are particularly useful for
handicapped installations and hospitals, greatly reducing the
need to manipulate awkward fixture handles and removing the
possibility of scalding caused by improper water control.
No-touch
faucets are available with (1) the sensor mounted in the wall
behind the sink, (2) the sensor integrated into the faucet, and
(3) the sensor mounted in an existing hot- or cold-water handle
hole and the faucet body in the center hole. For new
installations, the first or second option is usually best; for
retrofit installations, the last option may be the only one
feasible.
At sports facilities where
urinals experience heavy use, the entire restroom can be set up
and treated as if it were a single fixture.
Traffic can be detected and
the urinals flushed periodically based on traffic rather than
per person. This can significantly reduce water use. Computer
controls can be used to coordinate water usage to divert water
for fire protection when necessary.
Thermostatic valves can be used with electronic faucets to
deliver water at a preset temperature. Reducing hot water saves
a significant amount of energy.
A 24-volt transformer
operating off a 120-volt AC power supply is typically used, at
least with new installations. The transformer should be
UL-listed, and for security reasons the transformer and the
solenoid valve should be remotely located in a chase.
Many commercial faucets can be
retrofitted very quickly, requiring just seven to nine minutes
per fixture, according to Sloan Valve, a supplier of electronic
plumbing fixture controls.
Electronic faucet controls
offer the convenience and sanitary benefits of hands-free
operation. If the system is properly set up, significant water
and energy savings are achieved.
Battery-powered controls are
often used for retrofit applications because connecting AC
electricity to each fixture can be costly. For
battery-controlled units, most manufacturers recommend standard
alkaline batteries, which last two to three years with typical
usage; lithium batteries require less frequent replacement (they
can last up to five years), but they are more expensive. In
heavy usage areas, such as airports, battery-powered controls
are not recommended because of the need for frequent
replacement.
For hospitals or other medical
facilities, electronic fixtures should be used to the maximum
extent possible because they can help health care professionals
meet the Occupational Safety and Health Administration (OSHA)
protocols for hand-washing after patient contact.
Automated faucets are much
easier to clean since there are no handles in the way. The
industrial-grade solenoid valves used in these devices are far
more durable than their mechanical counterparts and are
virtually unaffected by chemicals and other constituents of the
water supply.
Some manufacturers estimate a
payback meet the Occupational Safety and Health Administration
(OSHA) protocols for hand-washing after patient contact.
Automated
faucets are much easier to clean since there are no handles in
the way. The industrial-grade solenoid valves used in these
devices are far more durable than their mechanical counterparts
and are virtually unaffected by chemicals and other constituents
of the water supply.
Some manufacturers estimate a
payback when a conventional fixture is replaced with an
electronic one. With faucets, this includes savings in water,
energy, and maintenance. With toilets and urinals, some of the
water savings may be attributable to reduced incidence of
intentional multiple flushing, a common practice with toilets
and urinals. ❑
