Water Smart
Guidelines
 Why
consider water-use efficiency?
A national
strategy which embraces water-use efficiency through improved design
and use of water-using appliances is part of a sustainable development
meeting the needs of this generation without making it difficult
or impossible for future generations to fulfil their own needs.
The
Australian Water Industry has recognised the potential for water-saving
in improving the designs of water-saving appliances such as toilets,
shower heads, washing machines and others.
This
strategy has been initiated as a practical means of assisting water
demand management where, for instance, capital expenditure on water
resource development (new dams, bores and water treatment, etc.)
might be reduced or deferred.
"Water
saved is exactly the same as water supplied" and "One
person's reduction in water use makes water available for someone
else to use" are maxims of the Rocky Mountains Institute (USA),
founded to foster the "efficient and sustainable use of resources
as a path to global security".
In
Denver, Colorado, USA, for example, the Institute shows that full
use of water-saving appliances in households would save more water
than a proposed US$1 billion dam would supply.
The
average cost of water saved in this way was a quarter the cost of
equivalent supply, treated to potable quality, from the proposed
new dam.
Further
to this it was shown that water for domestic irrigation could be
saved through improvements in irrigation efficiency alone, at one
tenth the cost of equivalent supply from the proposed new dam.
These
improvements did not include any changes in lawn size, quality or
type, nor in types of plants or techniques in landscape design.
The
Australian Government's "Commission for the Future²"
states that "Individuals can reduce their impact on the environment
by reducing demands on resources".
Amongst
recommendations are :-
*
Install aerators on taps and use water-efficient shower heads -
they use two to five times less water.
* Take shorter showers in preference to baths.
* Do not leave water running when it is not actively being used
in showering, shaving, brushing teeth or washing.
* Use low-flushing toilets.
* Use water-efficient washing machines and dishwashers, and run
them only when full.
* Use rainwater or rinsewater from clothes washing for plants and
garden.
* Use an underground drip irrigation system as water then goes directly
to the roots without evaporation or wastage.
These
tips point the way to further savings. With the help of manufacturers,
greater savings through "smart" designs are possible,
with benefits to Australia's producers and consumers.
Water
requires electrical power to supply it to a community. The less
water we use the less energy we consume for pumping, treatment and
heating. The environment suffers less in the long term.
Purpose
of these guidelines
These
Guidelines are an outline from more detailed recommendations intended
:-
*
To assist manufacturers of plumbing fittings and appliances - to
plan their manufacturing and marketing.
# For
plumbers and designers of in-house water installations - to encourage
them to conform to national trends in water conservation.
# For use by authorities - in formulating appropriate policies on
water efficiency in plumbing.
# The Guidelines reflect the goals of the Australian Water Industry
in its efforts to conserve water by ensuring that in-house plumbing
incorporates the best technology in water-use efficiency.
The
purpose is to indicate desirable criteria for water-use rates and
characteristics.
It
is now clear that modern, extremely efficient water-saving fittings
provide service equal or superior to their inefficient ancestors.
New
products and techniques allow today's households to use a third
less water than those of a decade ago, without sacrificing comfort
or changing lifestyles. However, water consumption per person is
increasing.
The
authorities are well aware that the water-use appliance industry
itself is the best suited to know and to cater for consumer preferences
and to develop and utilize water-efficient technologies. However,
initiative in water conservation would also be expected to come
from the public sector, namely the authorities, assigned the task
of water resource planning and maintenance.
¹.
Woodwell J.C. "Water Efficiency - alternative to US $1 billion
dam" WWI Journal, October 1989.
². Commonwealth of Australia "Personal Action Guide for
the Earth", July 1989.
Criteria
for in-house water-using appliances and plumbing
Better
technology needs to be developed and used for more water-use efficient
design associated with the following items :-
*
Shower heads
* Water Taps and Tap Aerators
* Dishwashers
* Clothes Washers
* Water Closets
* Urinals
* Sinks, Basins and Baths
* Water Plumbing Systems - Cold and Hot
* Domestic Garden Sprays
* Water Pressure Reduction and Inline Flow Restrictors
* Greywater reuse
* Evaporative Coolers.
Appliance
Labelling Scheme
A scheme
to recognize water-use efficiency through the rating and labelling
of manufacturers' appliances is administered by Standards Australia.
The scheme is voluntary and is intended to help consumers assess
the water-use efficiency of household appliances before they buy.
The
present scheme caters for three ratings :- A, AA and AAA.
*
A For an acceptable level of water efficiency.
* AA High water-use efficiency, notionally 25 percent less water-use
that for the A rating.
* AAA Excellent water-use efficiency, notionally 25 percent less
water-use than AA.
For
instance, a shower rose using 12 litres of water per minute would
receive an 'A' rating because its water-use rate does not exceed
that of the Standard for water-efficient shower heads. A shower
rose using 9 litres per minute would receive an 'AA' rating and
one using 6.75 litres per minute would receive an 'AAA' rating.
Standards
Australia has issued Miscellaneous Publication SAA MP64 - 1992 "Manual
of Assessment Procedure for Water Efficient Appliances" with
specifications for Shower Heads, Dishwashing Machines, Clothes washing
Machines, Urinals and Water Taps. Specifications for other products
such as water closets will be added when water efficient ratings
can be determined.
Initial
requests for labelling should be forwarded in writing to the Quality
Assurance Services Department of Standards Australia, listing each
product, its model and catalogue identifications, proposed applications,
methods of operation and rating claim.
Manufacturers
and distributors of water-using appliances are urged to support
the scheme to assist water authorities to defer the need to augment
water supply systems.
Keen
acceptance of this scheme will enhance market awareness of water
efficient products.
The
appliances which follow are commented on with respect to their present
water-using status and their potential with regard to water-use
efficiency.
1.
Shower Heads
The
shower is the highest user of water in the bathroom but the shower
head has, until recently, been designed without restriction of flow
rate as a consideration.
With
the new common use of mains-pressure water heaters the result has
been over-use of both water and heating energy. An average of 30.3%
of in-house water-use was attributed to the shower in the Perth
(1985) Study Report and :-
Shower
heads fall into two basic groups
1.
those for gravity-fed systems
2. those for mains-pressure systems.
The
greatest water wasting occurs when a gravity-type head is used in
a mains pressure system.
The
technology of using flow restrictors (washers with a small hole
in the middle) can cause poor shower quality and performance if
not matched with an appropriate shower rose. A properly-balanced
water flow is more achievable when flow restrictors are put in both
hot and cold taps. Energy-saving is closely related to water saving.
The
present situation
In
Australia, the maximum flow rate specified is 12 litres per minute.
In the USA and Europe, a maximum efficient rate of 8 to 9L/m and
a standard of 12L/m are the practice. Less than 5L/m is not considered
sufficient for an adequate shower. That Standard discharge rate
relates only to one particular pressure. Water Efficient shower
heads are already manufactured and sold, therefore no fundamental
development research will be necessary. Shower heads are available
that maintain a quality of service at low rates of flow. They vary
in "feel" from misty to needle-like, from pulsating to
a vigorous pounding flow. In addition, volume-control valves on
the shower head enable the user to reduce or shut off the flow in
midstream while maintaining a balanced mix of hot and cold water.
Water-use
efficient ratings for Standards Australia's Water Conservation Labelling
Scheme are :-
*
A 12.0L/m to more than 9.0L/m
* AA 9.0L/m to more than 6.8L/m
* AAA 6.8L/m or less.
2.
Water Taps
In-house
water use occurs under a number of categories; eg. kitchen, bathroom,
laundry; however the common denominator in many situations is the
tap. Taps come in many forms from the traditional loose jumper valve
variety, to ceramic discs and sophisticated electronic devices activated
by sensor. Each tap may offer a different advantage, eg. economy,
ease of use, greater hygiene, however, because they are all required
to control the delivery of water their design and operation is often
a key factor in water-use efficiency.
The
present situation
Water-use
efficient ratings for Standards Australia's Water Conservation Labelling
Scheme are :-
*
A Tap with a positive reliable seal and aerator
* AA As for A, plus adjustable single lever/handle control incorporating
an automatic flow-reducing feature
* AAA As for A, plus electronic or automatic self-closing feature.
3.
Dishwashers
Most
dishwashers are of similar size, ie. for 12 to 14 place settings.
There is already a number of machines giving adequate performance
without excessive water or power use.
As
is the case for clothes washers, the ideal would be a package of
both water and power use efficiency, clearly stated in terms of
dollar savings to the buyer.
Water-use
efficiency ratings for dishwashers under Standards Australia's Water
Conservation Labelling Scheme are, per program run :-
*
A More than 24L and not more than 32L
* AA More than 18L and not more than 24L
* AAA Not more than 18L.
4.
Clothes Washers
There
is a great variety of machines available. It is intended to encourage
the manufacture and use of those with the lower water-use per kilogram
of clothes.
Generally,
those that use less water also use less electrical power. This would
be improved by additional encouragement that consumers required
the suds-saving feature as well.
Water-use
efficiency ratings for clothes washers under Standards Australia's
Water Conservation Labelling Scheme are, per dry kg. of clothes
:-
*
A More than 24L and not more than 32L
* AA More than 18L and not more than 24L
* AAA Not more than 18L.
5.
Water Closets
Prior
to regulation or consumer education on water-wise toilets, it was
found that in Melbourne, water for flushing toilets was 18% of the
total residential water use and that the average water use in Perth
for toilet flushing was 32% of total in-house water use (i.e. 18.5%
of total residential water-use) second after the total bathroom
usage at 38.7%.
Significant
savings have already been made by the use of dual flush and reduced
flush cisterns in Australia and overseas.
Australian
water authorities, while mindful of the need for sufficient flushing
of gravity sewers, will support significant reduction in present
flush quantities. Manufacturers need to develop pans designed for
effective cleansing and clearing with reduced flush.
6.
Urinals
Water-use
saving for urinals using demand-flushing instead of cyclic flushing
has been estimated to be from 30% up to more than 80%, mainly effective
in the high-rise office blocks in the central business districts
of cities.
Few
overseas or Australian studies have extended to water-use efficiency
through the use of appropriate urinals and their flushing systems.
7.
Sinks, Basins, Baths
Where
water is retained for use in certain fixtures, clearly, long-term
wastage can occur where the container is bigger than necessary.
In many cases now, sensible design has reduced this waste already,
but relevant industry standards do no exist.
8.
WATER PLUMBING SYSTEMS - COLD AND HOT
The
principal causes of water wastage from property plumbing systems
are
*
leakage, mainly undetected below ground, but also through dripping
taps and toilet cisterns
* drawoff while waiting for the hot supply to reach operating temperature.
The
present situation
AS3500.1
has generally increased pipe sizes to limit velocity and to minimise
wear and water hammer.
Hot
water drawoff wastage factors are recognised as :-
*
remote location of water heater
* water run during warm-up of some instantaneous heaters
* low or high pressure schemes, determining pipework size
* pipework configuration, where to branch to offtakes
* use of recirculating hot water
* need for insulation of pipework
* water temperature settings too high
* oversized pipework.
* Investigations by CSIRO have included measuring the heat losses
from hot water pipes due to draughts. Heat losses were measured
at a range of velocities using a low-speed wind tunnel to provide
a closely controlled environment.
9.
Domestic Garden Irrigation
Watering
of domestic gardens is known to account for the greatest use of
scheme water in residential areas. In the Perth "Domestic Water
Use" study (1985) it was found that 47% of the average domestic
scheme water use per household was ex-house, of which 91% was for
irrigation. For Melbourne, 38% of average domestic use is ex-house.
10.
Water Pressure Reduction
Urban
water supply pressures in Australia are claimed to be among the
highest in the world. On average, they are certainly higher than
those in the U.K. and many European countries. Past studies have
identified excessive water pressure as a contributing factor in
water wastage.
Some
forms of water-use such as showering, rinsing and car washing are
largely time dependent. Unnecessary consumption can occur in high
pressure areas where consumers use more water than is required simply
because the tap is turned on a certain amount and the resulting
flow is in excess of requirements. There is potential to reduce
consumption by reducing supply pressures.
Pressure
reduction can be carried out on a district basis in distribution
systems or at individual properties.
Pressure
reduction within an authority distribution system has the advantage
of also reducing the rate of leakage and extending the working life
of the system.
A more
flexible method of pressure reduction is by the installation of
suitable devices on the service pipes to individual properties.
For this purpose, three types of valves are available :- pressure
reduction valves (PRV's), pressure limiting valves (PLV's) and pressure
ratio valves.
PLV's
and pressure ratio valves are cheaper, a typical domestic quality
20 mm valve costs about $60. These are usually non-adjustable and
are designed to limit outlet pressures to within a certain range
depending on inlet pressure and the nominal set pressure but are
not fail-safe.
PLV's
and pressure ratio valves, while relatively cheap, are able to be
tampered with and are not fail-safe.
PRV's
are more expensive, costing around $120 for a 20 mm size, are often
adjustable and will reduce outlet pressures to a predetermined value.
Both
PLV's and pressure ratio valves have limited service life which,
depending on the quality of the valve and the water supply, is in
the order of 5 to 10 years.
Pressure
reduction on individual properties can lead to unacceptable noise
levels.
11.
Greywater Re-use Systems
Water
re-use through greywater systems comes under two categories - commercial
and domestic. In general the systems collect, filter and store household
effluent from baths, showers and basins for re-use in toilet flushing
and garden watering.
Some
systems include disinfection. Kitchen effluent re-use is probably
not advisable because of the high level of fat and food particles.
Public
acceptance of recycling for toilet flushing has been achieved in
Europe, USA and Japan. The potential for greywater re-use in Australia
is great, particularly in arid and remote areas for domestic use,
as well as commercial, (motels, etc.)
12.
Evaporative Coolers
Optional
ways to operate an evaporative air cooler include :-
(a)
treating cooling water and recycling it,
(b) discharging a portion of the cooling water continuously without
treatment, or
(c) automatically dumping water when salt content becomes excessive.
*
Option (a) can be costly and a problem in disposal of treatment
by-products
* Option (b) usually results in a cleaner flow of water for disposal
* Option (c) has been claimed as the most water-use efficient method.
GreenPlumbers?® is an innovative initiative
developed by the Master Plumbers'
and Mechanical Services Association of Australia (MPMSAA). A
series of workshops have been designed to enhance plumbers' skills
and knowledge about the environmental considerations of their work.
These training opportunities place plumbers in a better position
to advise and inform consumers on topics such as: the benefits of
energy efficiency; water conservation or the most appropriate and
cost effective appliances to suit individual needs.
Call
Enviro-Friendly today on (02) 6282 6266, and find out how we can
help you
"Save water, save energy, save
money, and save the environment."
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