It is less important in facilities where the population
is stable and responsible, as in office buildings.
A disadvantage of current types of automatic
faucets is that they always operate with maximum
faucet flow, which makes it especially important
to maintain the aerators to limit flow. However,
the full flow is tolerable if the faucets operate only
when they are needed.
The older style of automatic faucet uses a dashpot
that allows flow for a fixed time interval after a
valve is depressed. This type is somewhat awkward
to use, and it tends to stick.
Newer automatic faucets use infrared sensors that
sense the presence of hands in the basin. This type
allows water flow only when needed, and forces
the user to be somewhat deliberate in hand washing.
To date, this type of equipment is expensive and