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Copyright © BEAM Society Limited. All rights reserved. Page 96
iii.
manufacturer specifications, technical data sheets with flow
rate information;
iv.
record photographs, “As-built” installation
Alternative:
i.
documentation, sensor type water taps installed in the
common area within the host building;
ii.
manufacturer specification/catalogue;
iii.
WSD WELS grade documentation, for all water tap, mixer tap,
and shower head (where installed);
iv.
record photographs, “As-built” installation
B
ACKGROUND
Hong Kong differs from most other places in the world in that the
majority of buildings have saltwater for flushing rather than using
potable water. Therefore the scope for potable water reductions may
be more limited here than elsewhere. Neither the quantification of
water use nor the potential for savings has been addressed in local
research literature. Nevertheless, evidence from other countries
suggests that reductions in water use may be achieved through the
use of water efficient devices and automatic controls.
For the majority of interior premises a limited amount of hand washing
and perhaps some manual dish washing will take place in the pantry.
It is not the intention to include water used for washing food or
produce (required for hygiene), nor water used for coffee making
machines, etc.
There is an increasing availability of devices and plumbing fixtures
which have demonstrated an ability to save water over the lifetime of
the system if installed and maintained properly. Flow rates can be
controlled to reduce excessive discharge at taps, faucets and
showers without detriment to the quality of water delivery. Substantial
evidence shows that the use of water-efficient plumbing fixtures
conserves water
[1].A number of studies in the US have measured
the impact of installing water-efficient plumbing fixtures through
sophisticated sensors, before and after comparisons of water bills, or
other means. Although the results varied, the studies concluded that
low-flow fixtures are effective in saving water.
High efficiency devices include low flow rate faucets or faucets with
aerated flows. The provision of automatic shut-off devices, particular
in public use areas, can save significant quantities of water. Examples
of automatic shut-off devices are spring-loaded (or push-once) taps,
electronic proximity sensors, etc., but excluding timed shut-off
devices.
1
United States General Accounting Office. Report to Congressional Requesters. Water Infrastructure. Water-Efficient
Plumbing Fixtures Reduce Water Consumption and Wastewater Flows. GA RCED-00-23. August 2000.