Problems and Pitfalls

MIL-HDBK-1165

water travels in parallel streams producing a clear flow of water

without being mixed with air (as in aeration). This produces

superior wetting ability over that of aerating faucets. Laminar

flow faucets are more expensive than aerating types but not

extravagantly so.

It is becoming an industry standard to add trickle

shut-off valves or levers to faucets. These levers allow the

user to shut off the water when performing some task that does

not require it, then to turn the water back on at the exact same

flow and temperature. The valve prevents the need to turn the

faucet off or to readjust the flow and temperature.

Some low-flow faucets are metered-valve type, or self-

closing, which will deliver a fixed quantity of water and then

shut off automatically. Another type of automatic faucet is

sensored. Self-closing faucets work with a spring-loaded lever

that slowly returns to its original position and turns off the

water. Sensored faucets, either infrared or ultrasonic, are

designed to turn on when a user's hands are placed under the

faucet, and turn off when the hands are removed.

5.2.4.5

Problems and Pitfalls. Faucet aerators need to be

checked periodically for clogging, some models clog more easily

than others and may need to be cleaned too often to be effective.

Some aerators may cause unacceptable performance or the

perception of poor performance, resulting in an increase in water

use.

The levers or handles that control the faucets on non-

sensoring types may also make a difference. Whereas sensored

faucets are designed to deliver water at a set volume and

temperature, single bar levers on non-sensored faucets tend to

cause the user to use more water than necessary to achieve a

desired volume and temperature. Redesigned levers can be

purchased which will deliver only a set temperature or even just

cold water unless deliberately pushed completely to the left for

hot water. Two-handled faucets also precipitate the same

problem. Foot-controlled levers for office lavatories may be an

alternative to sensored devices and help to prevent the spread of

germs. Sensored faucets are usually not appropriate for kitchens

due to the need for total volume and temperature control by the

user.

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