final report technical standard of water ......singapore, u.k. and u.s. therefore, this review...

FINAL REPORT

TECHNICAL STANDARD OF WATER SAVING DEVICES FOR NEW BUILDINGS

(AGREEMENT REF: 2C7TP09)

(HKPC REF: PROJECTS\40114221\4177D005)

Prepared by

Environmental Management Division Hong Kong Productivity Council

19th July 2010

Technical Standard of Water Saving Devices for New Buildings

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Executive Summary


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E1 Project Background

The scope of the original project was to provide recommendations for the Water Supplies

Department (WSD) water saving project which was focused on government buildings,

municipal venues and schools only. After completion of the original project, an additional

project was proposed to extend the study to develop recommendations of water saving

devices for new buildings.

In the original project, oversea technical standards of water saving devices were reviewed

so that technical standards, including the water efficiency grading system, the test

parameters and testing methodology, for Hong Kong context were developed. Technical

specifications, especially the recommended water efficiency grades, for different types of

water saving devices were also proposed for the WSD’s water saving project.

In this extended project, study has been conducted to review if any modifications to the

previous findings and recommendations developed in the original project were needed for

the application of water saving devices in the new buildings. The scope of study has been

agreed to confine to:

(a) water saving devices used in toilets and bathrooms, excluding disabled toilets, in

all new buildings except hospitals; and

(b) kitchen taps in all new buildings except hospitals.

As “new buildings” will include domestic and non-domestic buildings, the scope of this

study will cover all the general toilets and bathrooms, plus kitchen taps for new residential

establishments, hotels or similar establishments, schools, offices, shops, commercial

establishments, clinics, car parks and factories, etc.


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E2 Taps

E2.1 Overview of Oversea Technical Standards

Water efficiency grading schemes of taps have been implemented or being planned in

overseas. Several schemes have been well established in Australia, New Zealand,

Singapore, U.K. and U.S. Therefore, this review focuses on the standards established

from these five countries.

E2.2 Natures of the Schemes

The schemes established in Australia, New Zealand and Singapore are mandatory and all

the taps specified under these schemes must be registered, rated and labeled according

to the requirements of the standards. On the other hand, the schemes established in U.K.

and U.S. are implemented on a voluntary basis. As an initiative to promote water saving in

Hong Kong, the technical standard established in this project will be on a voluntary basis.

E2.3 Types of the Schemes

The schemes established in Australia, New Zealand and Singapore are of grading type.

Under these schemes, all the taps are rated to different grades of water efficiency in

accordance with the flow rate test results and are subject to the compliance with other

specified performance requirements. Labels will be affixed to the taps so as to indicate

their water consumption levels and efficiency grading.

The schemes established in U.K. and U.S. are of recognition type. Verification water

efficiency labels would be fixed to those taps that have met the specified water flow rate

requirement and are in compliance with the other specified performance criteria. Only one

flow rate is specified in this type of schemes. It may not be flexible enough if different types

of taps have to be used under different situations.

In view of the higher flexibility, a grading system is recommended for the proposed

technical standard for taps in Hong Kong.

E2.4 Types of Taps

In this study, “taps” means any tap or tap outlet that is for use over a basin and kitchen

sink, regardless of the operating mechanism.

Note: Tap types include combination taps, mixing taps, electronic taps/sensor taps;

This standard does not apply to any tap or tap outlet that is:


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(a) solely for use over a bath; or

(b) part of an appliance such as a chilled or boiling water dispenser.

E2.5 Water Efficiency Grading for Non-mixer Taps

Unlike the mixer taps that may have compatibility problems with the domestic water

heaters, non-mixer taps can actually achieve much lower flow rates than the mixer taps.

As non-mixer taps are mostly installed over basins, the Singaporean standard for basin

tap/mixer is benchmarked. As illustrated by the Singaporean standard, the best water

efficiency basin tap/mixer can achieve flow rates as low as <2 L/min.

The proposed water efficiency grading for non-mixer taps is shown in Table E2.1 and

illustrated in Figure E2.1.

Figure E2.1 Oversea Standards (Australia/New Zealand and Singapore) and

Recommended Hong Kong Standard for Taps


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Table E2.1 Water Efficiency Grading for Non-mixer Taps

Proposed Hong Kong Standard Nominal Flow Rate f (L/min)

Level 1 (Excellent) f ≤ 2.0

Level 2 (Very Good) 2.0 < f ≤ 4.0

Level 3 (Good) 4.0 < f ≤ 6.0

Level 4 (Ordinary) f > 6.0

# An extra merit is proposed to the water taps with automatic shut-off mechanism.

Level 4 - ordinary non-mixer taps equivalent to zero tick in the Singaporean standard for basin tap/mixer

Level 3 - Non-mixer taps with minimal water saving, equivalent to 1 tick in the Singaporean standard for basin tap/mixer

Level 2 - Non-mixer taps equivalent to 2 ticks in the Singaporean standard for basin tap/mixer

Level 1 - The best non-mixer taps equivalent to 3 ticks in the Singaporean standard for basin tap/mixer

E2.6 Test Parameters and Methodology for Non-mixer Taps

The nominal flow rates of the water taps shall be tested in accordance with the testing

methodology in AS/NZS 3718:2005. The water taps are then rated to different levels

according to the nominal flow rate test results subject to the compliance with other

performance requirements as shown in Table E2.2.

Table E2.2 Performance Requirements for Water Taps

Performance Property Performance Requirements The difference between the highest and lowest average flow rates measured in the nominal flow rate measurement

The difference shall not exceed 2.0 L/min.

Endurance of the flow controller The flow rate shall be within ±1 L/min of the nominal flow rate, as determined in the flow rate test.

E2.7 Recommended Water Efficiency Grade for Non-mixer Taps

In general, Level 1 will be recommended from the perspective of water saving unless there

are technical applicability problems or inadequate local availability hindering the use of

Level 1 non-mixer taps.

As demonstrated from the registration of water efficiency taps in Singapore, taps with flow

rates <2 L/min are technically feasible and available in the market although they may not

be currently common in Hong Kong.


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As shown in Table E2.3, it is recommended to use Level 1 (Excellent) water efficiency

non-mixer taps in the toilets of all new buildings except hospitals.

Table E2.3 Recommended Grade of Water Efficiency Non-mixer Taps

Assessment Criteria Level 1 Level 2 Level 3

Water saving performance ��

Technical applicability ��

Availability in local market ��

Recommended grade Excellent Very Good Good

E2.8 Other Concerns for Non-mixer Taps

Some people may think that hand washing may not be so effective when using a water

efficiency tap and would concern about the hand hygiene. The hand hygiene guidelines

given by both the World Health Organization (Pittet et al., 2009) and the Centre for Health

Protection of Hong Kong (2009) only suggest rinsing hands thoroughly under running

water. They do not specify how much water to be used or how long for the rinsing.

Therefore, technically, a water efficiency tap will not impair the hand hygiene during hand

washing provided that sufficient amount of running water is used. In fact, there are no

reports from overseas, like Singapore or Australia, saying that water efficiency taps will

affect hand hygiene. However, users may consider lower levels of water efficiency taps if

they have concerns about hygiene in some critical applications, like clinics or elderly

centres.

Users shall also be reminded that as the flow rates of the water efficiency taps will

definitely be smaller than those of ordinary taps, longer time will be required by the water

efficiency taps to fill up containers, like kettles or buckets. Users may consider using taps

of lower water efficiency levels if the afore-mentioned issue is very critical to their

operations.

From the environmental perspective, taps equipped with energy saving features, such as

solar panels to drive the electronic sensors, shall be encouraged to use.

In respect of the taps with automatic shut-off devices, the time for the tap to be closed

should be as short as possible in order to minimize the water wastage. Taps with

maximum closing time of no more than 1 min are recommended.

The recommended grades of water efficiency of non-mixer taps for different applications

are summarized in Table E2.4.


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Table E2.4 Recommended Grades of Non-mixer Taps for Various Applications

Level 1# Excellent

(f ≤ 2.0 L/min)

Level 2# Very Good

(2.0 L/min < f ≤ 4.0 L/min)

Level 3# Good

(4.0 L/min < f ≤ 6.0 L/min)

- No technical constraints; - Used in public places; - For general personal hygiene purpose; - Mainly for hand washing; - Not recommended for high volume

usage such as cleansing and filling up containers like kettles and buckets,

- Examples: Toilets and pantries for offices, shopping malls and cultural venues (e.g. libraries and museums etc.); Guest rooms of hotels and serviced apartments.

- No technical constraints; - Used in private and public facilities; - For general personal hygiene purpose; - For high volume usage such as

cleansing purpose and filling up containers, like kettles and buckets;

- For facilities that involve physical activities such as sports which lead to frequent and high volume usage.

- For facilities which have peak demand of water and where prolonged queuing time is required in case of low water flow rate;

- Examples: Toilets for residential premises, including dormitories of boarding schools and universities, performance venues (e.g. town halls, cultural centres, theatres etc.), schools and leisure venues (e.g. sports centres, playgrounds, sports stadiums, swimming pools etc,

- No technical constraints; - Used in places where require critical

hygienic condition; - For higher personal hygiene

requirement; - For high volume usage that includes

cleansing of dirty substances to remove germs.

- Examples: Elderly homes, child care centres, nursery or social services centres; Clinic, medical centres and rehabilitation centres; Workshops and machinery plants.



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E2.9 Water Efficiency Grading for Mixer Taps

Mixer taps are normally associated with some water heating systems to provide hot water

supply. The water efficiency grading for mixer taps shall be designed with due

consideration of the possible compatibility problems when water efficiency mixer taps are

connected to the domestic water heaters.

According to the compatibility test, the flow-controlled water heaters, no matter if town gas,

LPG or electricity is used, have minimum flow rate requirement of about 3 L/min. Whereas,

the pressure-controlled water heaters, again no matter if town gas, LPG or electricity is

used, normally require higher minimum water flow rates than the flow-controlled ones to

trigger the operations. Their values vary from 3 L/min to about 5.8 L/min. In the case of

storage type water heaters, no minimum flow rate is required for their operation.

The flow rates of taps are specified in terms of nominal flow rates which are the average

values of the measured water flow rates under pressure of 150 kPa, 250 kPa and 350 kPa.

If the maximum difference between the highest and lowest average flow rates of the mixer

taps is restricted to not exceeding 2.0 L/min as proposed in the Hong Kong standard and

the water supply pressure is maintained at no less than 150 kPa, the actual flow rates of a

water efficiency mixer tap under different pressures will be its nominal flow ±1.0 L/min. In

order to ensure that the water efficiency mixer taps can deliver water flow rates that are

adequate to trigger the operation of the water heaters, the lower limits of the taps’ flow

rates, i.e. nominal flow -1.0 L/min, must be greater than the minimum flow rates of the

water heaters. Hence, since the minimum flow rate requirement of the flow-controlled

water heaters is about 3 L/min, the nominal flow rates of any compatible water efficiency

mixer taps should be greater than 4 L/min. Whereas, as the minimum flow rate

requirement of the pressure-controlled water heaters is about 3-5.8 L/min, the nominal flow

rates of any compatible water efficiency mixer taps should not be less than 6.8 L/min.

Since the storage type water heaters, including the centralized water heating system, do

not have any minimum flow rate requirement to trigger their operation, there is basically no

minimum requirement for the nominal flow rates of the compatible water efficiency mixer

taps.

Based on the above rationales, the water efficiency grading as listed in Table E2.5 and

illustrated in Figure E2.1 is proposed for mixer taps used in new buildings.


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Table E2.5 Water Efficiency Grading for Mixer Taps




Level 3 (Good) 7.0 < f ≤ 9.0


* An extra merit is proposed to the mixer taps that can achieve a nominal flow rate ≤ 2

L/min;


Level 4 - ordinary mixer taps which are compatible to all types of water heaters, equivalent to zero tick in the Singaporean standard for shower tap/mixer

Level 3 - mixer taps with minimal water saving, which are compatible to the storage type water heaters and both flow-controlled and pressure-controlled instantaneous type water heaters, equivalent to 1 tick in the Singaporean standard for shower tap/mixer

Level 2 - mixer taps which are compatible to the storage type water heaters and flow-controlled instantaneous type water heaters, equivalent to 2 ticks in the Singaporean standard for shower tap/mixer

Level 1 - mixer taps which are only compatible to the storage type water heaters and centralized water heating system, equivalent to 3 ticks in the Singaporean standard for shower tap/mixer

With the proposed water efficiency levels for mixer taps, it is anticipated that no serious

compatibility problem with the water heaters shall be encountered if the public is aware of

the types of water heaters that each category of mixer taps are compatible to.

Besides, when storage type water heaters or centralized water heating systems are used,

the compatibility problem between the water efficiency mixer taps and the water heaters

no longer exists. There is room to pursue higher water efficiency than just <5 L/min. This is

particularly true for those high water consuming non-domestic users, like hotels, hostels,

sports centers, etc., where centralized water heating systems are used. In order to

encourage the use of the best water efficiency mixer taps in the market, an extra credit is

proposed for mixer taps that can achieve nominal flow rates <2 L/min. This water efficiency

level will be equivalent to the best water efficiency level achieved for non-mixer taps as

shown in Figure E2.1.

E2.10 Test Parameters and Methodology for Mixer Taps

The nominal flow rates of the mixer taps shall be tested in accordance with the testing

same methodology as that for non-mixer taps in accordance with the testing methodology


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in AS/NZS 3718:2005. The mixer taps are then rated to different grades according to the

nominal flow rate test results subject to the compliance with other performance

requirements as shown in Table E2.6.

Table E2.6 Performance Requirements for Mixer Taps

Performance Property Performance Requirements

The difference between the highest and lowest average flow rates measured in the nominal flow rate measurement



E2.11 Recommended Water Efficiency Grade for Mixer Taps

In general, Level 1 will be recommended from the perspective of water saving unless there

are technical applicability problems or inadequate local availability hindering the use of

Level 1 mixer taps.

Based on the compatibility test results (HKPC, 2010), Level 1 water efficiency mixer taps

will be recommended if storage type water heaters or centralized water heating systems

can be used in the new buildings. Whereas, if instantaneous type water heaters have to be

used, it is recommended to use flow-controlled type water heaters and Level 2 water

efficiency mixer taps will be compatible to these water heaters. However, if only pressure-

controlled type instantaneous water heaters can be used, it will be advisable to install

Level 3 water efficiency mixer taps in order to avoid any compatibility problem between the

taps and the water heaters.

As shown in Table E2.7, water efficiency mixer taps of different levels will be

recommended according to the types of domestic water heaters used in the new buildings.


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Table E2.7 Recommended Grade of Water Efficiency Mixer Taps

Assessment Criteria

Level 1 Level 2 Level 3 Level 4

Water saving performance

��

Technical applicability

Applicable to storage type

water heaters


and flow-controlled

water heaters

Applicable to storage type, flow-

controlled and pressure-controlled

water heaters

Applicable to all types of

water heaters

Availability in local market

��

Recommended grade

Excellent Very Good Good Ordinary

E2.12 Other Concerns for Mixer Taps

The water supply pressure at the cold water inlet of the individual water heater is

maintained at no less than 150 kPa.

Similar to non-mixer taps, users may consider lower levels of water efficiency taps if they

have concerns about hygiene in some critical applications, like clinics or elderly centres.

Users shall also be reminded that as the flow rates of the water efficiency taps will

definitely be smaller than those of ordinary taps, longer time will be required by the water

efficiency taps to fill up containers, like kettles or buckets. Users may consider using taps

of lower water efficiency levels if the afore-mentioned issue is very critical to their

operations.

When storage type water heaters or centralized water heating systems are used, users

may consider using mixer taps with nominal flow rates of <2 L/min so as to get an extra

credit.

Users shall also consider using mixer taps with automatic shut-off mechanism and an

extra credit will be given to recognize the additional benefit in water saving.

The recommended grades of water efficiency of non-mixer taps for different application are

summarized in Table E2.8.


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Table E2.8 Recommended Grades of Mixer Taps for Various Applications

Level 1*, # Excellent

(f ≤ 5.0 L/min)

Level 2# Very Good

(5.0 L/min < f ≤ 7.0 L/min)

Level 3# Good

(7.0 L/min < f ≤ 9.0 L/min)

- Applicable to centralized water heating system or storage type heaters;

- Used in plubic places; - For general personal hygiene purpose - Not recommended for high volume

usage such as cleansing and filling up containers like kettles and buckets;

- Examples: Toilets and pantries for offices, shopping malls, cinemas, theatres and so on; Guest rooms of hotels and serviced apartments; Toilets for schools, club houses and sport centres and so on.

- Applicable to centralized water heating system or storage type heaters and flow-controlled water heaters;

- Used in private places and public facilities;

- For general personal hygiene purpose; - For facilities that involve physical

activities such as sports which lead to frequent and high volume usage;


- For high volume usage such as cleansing purpose and filling up containers like kettles and buckets;

- Examples: Toilets for residential premises including dormitories of boarding schools and universities; Kitchens.

- Applicable to centralized water heating system or storage type heaters , flow-controlled water heaters and pressure-controlled water heaters ;

- Used in places where require critical hygienic condition;

- For higher personal hygienic requirement;


- For high volume usage that includes cleansing of dirt substances to remove germs;

- Examples: Elderly homes, child care centres, nurseries or social services centres; Clinic, medical centres and rehabilitation centres; Factories, warehouses, workshops and so on.

* An extra merit is proposed to the mixer taps that can achieve a nominal flow rate ≤ 2 L/min;



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E3 Urinals


Water efficiency grading scheme of urinals have been implemented or being planned in overseas. Several schemes have been well established in Australia, New Zealand, Singapore and U.S. Therefore, this review focuses on the standards established from these four countries. E3.2 Natures of the Schemes

The schemes established in Australia, New Zealand and Singapore are mandatory and all the urinals specified under these schemes must be registered, rated and labeled according to the requirements of the standards. On the other hand, the scheme established in U.S. is implemented on a voluntary basis. As an initial initiative to promote water saving in Hong Kong, the technical standard established in this project will be on a voluntary basis. E3.3 Types of the Schemes

The schemes established in Australia, New Zealand and Singapore are of grading type. Under these schemes, all the urinals are rated to different grades of water efficiency in accordance with the volume of discharge test results and are subject to the compliance with other specified performance requirements. Labels will be affixed to the urinals so as to indicate their water consumption levels and efficiency grading. The scheme established in U.S. is of recognition type. Verification water efficiency labels would be fixed to those urinals that have met the specified volume of discharge requirement and are in compliance with the other specified performance criteria. Only one volume of discharge is specified in this type of scheme. It may not be flexible enough if different types of urinals have to be used under different situations. In view of the higher flexibility, a grading system is recommended for the proposed technical standard for urinals in Hong Kong. E3.4 Types of Urinals

In this study, “urinals” means: (a) a urinal suite; (b) a urinal; (c) a urinal flushing control mechanism; or a combination of a urinal and urinal flushing control mechanism This study does not apply to waterless urinals and trough urinals. Waterless urinals are not commonly used and their performance is yet to be assessed and proved. If necessary, an additional piece of technical standard specifying the applicable performance criteria and testing methodologies may be developed for the waterless urinals in the future. Unlike wall-hung urinals, trough urinals are normally tailor-made in Hong Kong, which makes trough urinals difficult to satisfy the required performance criteria of the proposed technical standard of water efficiency urinals, like flushing test and splash test. However, there are no suitable factory-tested standard trough urinals available in Hong Kong market.


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In this regard, it is recommended not to include trough urinals in the proposed technical standard of water efficiency urinals for new buildings in Hong Kong. E3.5 Water Efficiency Grading

The water efficiency grading for urinals proposed for new buildings is listed in Table E3.1 and illustrated in Figure E3.1.

Table E3.1 Water Efficiency Levels for Urinals

Proposed Hong Kong Standard Volume of Discharge f (L)



Level 3 (Good) 2.5 < f ≤ 4.5


Level 4 - conventional urinals currently used (mostly flushed with cisterns) Level 3 - urinals with minimal water saving Level 2 - equivalent to 1-3 stars in the Australian/New Zealand standards Level 1 - the best flushing control mechanisms in the market (mostly flushing with

electronic sensor flushing valves), equivalent to 4-6 stars in the Australian/New Zealand standards


Recommended Hong Kong Standard for Urinals

E3.6 Test Parameters and Methodology

The volume of discharge of the urinals shall be tested in accordance with the testing methodology in AS/NZS 3982:1996. The urinals are then rated to different grades according to the volume of discharge test results subject to the compliance with other performance requirements as shown in Table E3.2.


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Table E3.2 Performance Requirements for Urinals

Performance Property Performance Requirements Flushing test for single stall wall-hung urinals

The urinal shall flush coloured water over the serviced area 130 mm below the spreader on a spreader type urinal and 50 mm below the weir outlet on a box rim type urinal.

Splash test for urinals The urinals shall not splash water onto the floor. E3.7 Recommended Water Efficiency Grade

In the previous study for WSD’s water saving project, the recommended water efficiency grade of the water efficiency urinals was Level 2. It was due to the consideration about the difficulties to retrofit the existing urinals to achieve Level 1. However, there is no such constraint for new buildings. In general, Level 1 will be recommended from the perspective of water saving unless there are technical applicability problems or inadequate local availability hindering the use of Level 1 urinals. The flushing performance of urinals is mainly dependent on two factors: the flushing volume setting of the flushing apparatus and the design of urinal pans. The most common types of flushing apparatus in Hong Kong are flushing cisterns and flushing valves. In light of the type test results in the previous study, electronic sensor type flushing valves shall have no problem to meet the requirements of Level 1. As for the urinal pans, the type tests in the previous study have revealed that a number of urinal pans can be classified as Level 1. In this regard, there should be no technical applicability problems or inadequate local availability hindering the use of Level 1 urinals in Hong Kong. As shown in the assessment result of Table E3.3, it is recommended to use wall-hung type Level 1 (Excellent) urinals in the toilets of all new buildings except hospitals.

Table E3.3 Recommended Grade of Water Efficiency Urinals Assessment Criteria Level 1 Level 2 Level 3 Water saving performance ��



Recommended grade Excellent Very Good Good E3.8 Other Concerns

Trough urinals are not recommended as water efficiency urinals for new buildings because of no suitable factory-tested standard products available in Hong Kong market. However, users shall be reminded that a trough urinal can normally occupy less space than the equivalent number of wall-hung urinals. Therefore, if it is intended to install water efficiency urinals in the new buildings, adequate space shall be allocated to accommodate enough number of wall-hung urinals. A reduced flush mode can be automatically activated when urinals are used frequently in public toilets with high volume usage.


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It is advisable to install extra strainers before the flushing valves’ water filters so as to prevent potential blockage of the water filters by solid particles such as silt and rust, in the flushing water.


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E4 Toilets/Lavatory Equipment


Water efficiency grading scheme of toilets/lavatory equipment have been implemented or being planned in overseas. Several schemes have been well established in Australia, New Zealand, Singapore, U.K. and U.S. Therefore, this review focuses on the standards established from these five countries. E4.2 Natures of the Schemes

The schemes established in Australia, New Zealand and Singapore are mandatory. And all the toilets/lavatory equipment specified under these schemes must be registered, rated and labeled according to the requirements of the standards. On the other hand, the schemes established in U.K. and U.S. are implemented on a voluntary basis. As an initiative to promote water saving in Hong Kong, the technical standard established in this project will be on a voluntary basis. E4.3 Types of the Schemes

The schemes established in Australia, New Zealand and Singapore are of grading types. Under these schemes, all the toilets/lavatory equipment are rated to different grades of water efficiency in accordance with the volume of discharge test results and are subject to the compliance with other specified performance requirements. Labels will be affixed to the toilets/lavatory equipment so as to indicate their water consumption levels and efficiency grading. The schemes established in U.K. and U.S. are of recognition types. Verification water efficiency labels would be fixed to those toilets/lavatory equipment that have met the specified volume of discharge requirement and are in compliance with the other specified performance criteria. Only one value of “volume of discharge” is specified in this type of schemes. It may not be flexible enough if different types of toilets/lavatory equipment have to be used under different situations. In view of the higher flexibility, a grading system is recommended for the proposed technical standard for toilets/lavatory equipment in Hong Kong. E4.4 Types of Toilets/Lavatory Equipment

In this study, “toilets/lavatory equipment” means: (a) a toilet suite; or (b) a water closet pan; or (c) a water closet cistern; or (d) a combination of a water closet and cistern Unlike water closets which have dominated the market, squat toilets are seldom used in new buildings. In addition, squat toilets have very few choices in the market and little performance data are available. In general, squat toilets require more water for flushing than the water closets. In this regard, it is recommended not to include squat toilets in the proposed technical standard of water efficiency toilets/lavatory equipment for new buildings in Hong Kong.


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E4.5 Water Efficiency Grading

The water efficiency grading for toilets/lavatory equipment proposed for new buildings is listed in Table E4.1 and illustrated in Figure E4.1.

Table E4.1 Water Efficiency Levels for Toilets/Lavatory Equipment

Proposed Hong Kong Standard Equivalent Volume of Discharge

f (L)



Level 3 (Good) 4.5 < f ≤ 7.5


Level 4 - ordinary toilets with single flush cisterns currently used Level 3 - toilets equipped with better single flush cisterns Level 2 - toilets equipped with dual flush cisterns, equivalent to 2-3 stars in the

Australian/New Zealand standards Level 1 - toilets equipped with the best dual flush cisterns available in the market,

equivalent to 4-6 stars in the Australian/New Zealand standards


Recommended Hong Kong Standard for Toilets/Lavatory Equipment


The volume of discharge for full-flush and reduced-flush (if any) of the toilets/lavatory equipment shall be tested in accordance with the testing methodology in AS/NZS 1172.1:2005 and AS/NZS 1172.2:1999. The toilets/lavatory equipment are then rated to different grades according to the equivalent volume of discharge test results subject to the compliance with other performance requirements as shown in Table E4.2.


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Table E4.2 Performance Requirements for Toilets/Lavatory Equipment

Performance Property Performance Requirements Full-flush test on water closets

A pan shall discharge from the outlet spigot of the pan all of the paper in at least two of the three tests.

Reduced-flush test on water closets

A pan shall discharge from the outlet spigot of the pan all of the paper in at least two out of the three tests.

Solids discharge test A pan shall discharge all four test pieces with a trailing water volume of not less than 2.5 L in at least eight of ten consecutive tests. If the pan does not pass in the initial ten tests, the procedure may be repeated for a further ten tests and the trailing water volume shall be not less than 2.5 L in at least sixteen out of the twenty tests.

Splash test A pan shall not splash water onto the floor. Wetting test A pan shall wash the sawdust from all areas more than 50

mm below the lower edge of the flushing rim. Reduced-flush liquid contaminant test

No more than 7% of dye shall be left in the sump after flushing.

E4.7 Recommended Water Efficiency Grade

In the previous study for WSD’s water saving project, the recommended water efficiency grade of the water efficiency toilets/lavatory equipment was Level 1. In general, Level 1 will be recommended from the perspective of water saving unless there are technical applicability problems or inadequate local availability hindering the use of Level 1 toilets/lavatory equipment. The water efficiency technology for water closets (especially for wash down type) is quite mature. All grades of water closets can be easily found in the market although Level 1 toilets/lavatory equipment may not be as common as the others. As shown in the assessment result of Table E4.3, it is recommended to use Level 1 (Excellent) water efficiency toilets/lavatory equipment in the toilets of all new buildings except hospitals.

Table E4.3 Recommended Grade of Water Efficiency Toilets/Lavatory Equipment Assessment Criteria Level 1 Level 2 Level 3 Water saving performance ��





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E5 Showers


Water efficiency grading scheme of showers have been implemented or being planned in overseas. Several schemes have been well established in Australia, New Zealand, Singapore and U.K. Therefore, this review focuses on the standards established from these four countries. E5.2 Natures of the Schemes

The schemes established in Australia and New Zealand are mandatory and all the showers specified under these schemes must be registered, rated and labeled according to the requirements of the standards. On the other hand, the schemes established in Singapore and U.K. are implemented on a voluntary basis. As an initiative to promote water saving in Hong Kong, the technical standard established in this project will be on a voluntary basis. E5.3 Types of the Schemes

The schemes established in Australia, New Zealand and Singapore are of grading types. Under these schemes, all the showers are rated to different grades of water efficiency in accordance with the flow rate test results and are subject to the compliance with other specified performance requirements. Labels will be affixed to the showers so as to indicate their water consumption levels and efficiency grading. The schemes established in U.K. are of recognition type. Verification water efficiency labels would be fixed to those showers that have met the specified water flow rate requirement and are in compliance with the other specified performance criteria. Only one flow rate is specified in this type of schemes. It may not be flexible enough if different types of showers have to be used under different situations. In view of the higher flexibility, a grading system is recommended for the proposed technical standard for showers in Hong Kong. E5.4 Types of Showers

A shower may include the showerhead and the accessories such as fixed or pivot arm, a flexible hose (with or without a flow controller), tap top assemblies or other components, which is used solely for personal bathing. There are different types of showers available in the markets, such as: (a) wall mounted shower and; (b) hand shower. E5.5 Water Efficiency Grading

The water efficiency grading for showers proposed for new buildings is listed in Table E5.1 and illustrated in Figure E5.1.

Table E5.1 Water Efficiency Levels for Showers


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Hong Kong Standard Nominal Flow Rate

f (L/min)



Level 3 (Good) 12.0 < f ≤ 16.0

Level 4 (Ordinary) f > 16.0 Level 4 - ordinary showers currently used Level 3 - showers equivalent to 1 star in the Australian/New Zealand standards Level 2 - showers equivalent to 2 stars in the Australian/New Zealand standards Level 1 - The best water efficient showers equivalent to 3-6 stars in the

Australian/New Zealand standards

Figure E5.1 Oversea Standards (Australia/New Zealand and Singapore) and Recommended Hong Kong Standard for Showers


The nominal flow rates of the showers shall be tested in accordance with the testing methodology in AS/NZS 3662:2005. The showers are then rated to different grades according to the nominal flow rate test results subject to the compliance with other performance requirements as shown in Table E5.2.


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Table E5.2 Performance Requirements for Showers



Mean spray spread angle The mean spray spread angle shall be between 0°and 8°.

Temperature drop The temperature drop shall not exceed 3°C

Endurance of the flow controller (if incorporated in a shower or being a component of a shower)

The flow rate shall be within ±1 L/min of the nominal flow rate, as determined in the flow rate test.

E5.7 Recommended Water Efficiency Grade

In general, Level 1 will be recommended from the perspective of water saving unless there are technical applicability problems or inadequate local availability hindering the use of Level 1 showers. Technically, the water saving technology for showers is actually quite mature in overseas although water efficiency showers are not commonly used in Hong Kong. Most of the water efficiency showers achieve flow reduction by means of flow restrictors. Nevertheless, similar to the mixer taps, showers are normally associated with some water heating systems to provide hot water supply. There may be compatibility issues when water efficiency showers are connected to the domestic water heaters as every instantaneous type domestic heater requires a minimum flow in order to trigger its operation. If the flow rates of the water efficiency showers are too small, especially when the water supply pressure is relatively low, the water heaters may not operate. To resolve this compatibility problem, it is recommended: (a) To maintain a water supply pressure at the cold water inlet of the individual water

heater of at least 150kPa at the cold water inlet of the individual water heater in all new buildings;

(b) To limit the variation of the actual flow rates for each water efficiency shower under pressures between 150 kPa and 350 kPa to within ±1 L/min of the nominal flow rate as determined in the flow rate test; and

(c) To ensure that the actual flow rates of the water efficiency showers can satisfy the minimum flow requirements of domestic water heaters.

The flow rates of showers are specified in terms of nominal flow rates which are the average values of the measured water flow rates under pressure of 150 kPa, 250 kPa and 350 kPa. For the highest floors of a building, fresh water is normally supplied from the rooftop fresh water tank by gravity without any booster pump. The water supply pressure can be less than 150kPa. In order to make sure that the actual flow rates of the water efficiency showers would not be far below their specified nominal flow rates, causing operational problem to the domestic water heaters, it is recommended to explicitly specify a minimum water supply pressure of at least 150 kPa to be maintained at the cold water inlet of the individual water heater in all new buildings.


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Currently, there is no restriction for the maximum difference between the highest and lowest average flow rates of the showers in Hong Kong. Again, to avoid great deviation of the actual flow rates of the water efficiency showers from their specified nominal flow rates, it is deemed necessary to limit the variation of the actual flow rates for each water efficiency shower under pressures between 150 kPa and 350 kPa to within ±1 L/min of the nominal flow rate, as stated in the performance requirements in Table E5.2. According to the compatibility test, the flow-controlled water heaters, no matter if town gas, LPG or electricity is used, have minimum flow rate requirement of about 3 L/min. Whereas, the pressure-controlled water heaters, again no matter if town gas, LPG or electricity is used, normally require higher minimum water flow rates than the flow-controlled ones to trigger the operations. Their values vary from 3 L/min to about 5.8 L/min. In the case of storage type water heaters, no minimum flow rate is required for their operation. Therefore, if the variation of the actual flow rates for each water efficiency shower under pressures between 150 kPa and 350 kPa is restricted to within ±1 L/min of its nominal flow rate, the nominal flow rate needs to be above 6.8 L/min in theory in order to activate the domestic water heater’s operation. Hence, the proposed Level 1 water efficiency showers with nominal flow rates of <9 L/min shall basically be compatible to most domestic water heaters if the previous recommendations (a) to (c) can be done. All grades of water efficiency showers are available in the market although Level 1 showers may not be as common as the others. As shown in the assessment result of Table E5.3, it is recommended to use Level 1 (Excellent) water efficiency showers in the toilets of all new buildings except hospitals.

Table E5.3 Recommended Grade of Water Efficiency Showers Assessment Criteria Level 1 Level 2 Level 3 Water saving performance ��



Recommended grade Excellent Very Good Good E5.8 Other Concerns

The designers of the buildings should contemplate the issue of flexibility in temperature adjustment and the minimum flow rate requirement to trigger the water heater. In general, all grades of water efficient showers are applicable to flow controlled type water heaters. Only water efficient showers with water flow rate no less than 7 L/min under inlet pressure of 150kPa at shower head are suggested to be used in conjunction with pressure controlled type water heaters and no water efficient showers are recommended for electric water heaters which have relatively fairly high minimum flow rate requirement. In case of storage type electric water heater which has no minimum flow rate requirement, all grades of water efficient showers with generally no hampering of flexibility in water temperature adjustment are recommended.


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E6 Summary of the Recommended Grades for Various Water Saving

Devices

The recommended water efficiency grades of the water saving devices, including taps, urinals, toilets and showers, to be used in the recommendation are summarized in Tables E6.1 to E6.3.

Table E6.1 Recommended Grades of Non-Mixer Taps and Mixer Taps Various Water Saving Devices

Recommended Levels

Equivalent Performance of Water Efficiency

Other Concerns

Non-Mixer Taps Level 1 # Nominal flow rate: ≤ 2.0 L/min for taps

Level 1 #,* Nominal flow rate: ≤ 5.0 L/min Applicable to storage type water heaters

Level 2 #,* Nominal flow rate: 5.0 L/min < f ≤ 7.0 L/min Applicable to storage type and flow-controlled water heaters

Mixer Taps

Level 3 #,* Nominal flow rate: 7.0 L/min < f ≤ 9.0 L/min Applicable to storage type, flow-controlled and pressure-controlled water heaters

• The water supply pressure at the cold water inlet of the individual water heater is maintained at no less than 150 kPa.

• Lower water efficiency levels may be considered if more concerns about hygiene in some critical applications, like clinics or elderly centres;

• Longer time will be required for filling up containers;

• Lower water efficiency levels may be considered if the afore-mentioned issue is very critical to their operations;

• From the environmental perspective, taps equipped with energy saving features, such as solar panels to drive the electronic sensors, shall be encouraged to use;

• In respect of the taps with automatic shut-off devices, the time for the tap to be closed should be as short as possible in order to minimize the water wastage. Taps with maximum closing time of no more than 1 min are recommended.

# An extra merit is proposed to the water taps with automatic shut-off mechanism * An extra merit is proposed for using mixer taps with nominal flow rates of not more

than 2 L/min


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Table E6.2 Recommended Grades of Urinals and Toilets/lavatory equipment Various Water Saving Devices

Recommended Levels


Other Concerns

Urinals Level 1 Volume of discharge: f ≤ 1.5 L/unit

• Trough urinals are not recommended as water efficiency urinals for new buildings;

• Adequate space shall be allocated to accommodate enough number of wall-hung urinals;

• A reduced flush mode can be automatically activated when urinals are used frequently in public toilets with high volume usage;

• It is advisable to install extra strainers before the flushing valves’ water filters so as to prevent potential blockage of the water filters by solid particles such as silt and rust, in the flushing water.

Toilets/lavatory equipment

Level 1 Equivalent volume of discharge: ≤ 3.5 L (reduced flush: ≈ 3 L; full flush: ≈ 4.5 L)

• Squat toilets are not recommended as water efficiency toilets for new buildings.


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Table E6.3 Recommended Grades of Showers Various Water Saving Devices

Recommended Levels


Other Concerns

Showers Level 1 Nominal flow rate: ≤ 9.0 L/min


• The designers of the buildings should contemplate the issue of flexibility in temperature adjustment and the minimum flow rate requirement to trigger the water heater;

• In general, all grades of water efficient showers are applicable to flow controlled type water heaters;

• Only water efficient showers with water flow rate no less than 7 L/min under inlet pressure of 150kPa at shower head are suggested to be used in conjunction with pressure controlled type water heaters and no water efficient showers are recommended for electric water heaters which have relatively fairly high minimum flow rate requirement;

• In case of storage type electric water heater which has no minimum flow rate requirement, all grades of water efficient showers with generally no hampering of flexibility in water temperature adjustment are recommended.


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Table of Contents

Executive Summary................................................................................... i E1 Project Background .................................................................................... ii E2 Taps .......................................................................................................... iii

E2.1 Overview of Oversea Technical Standards..................................... iii E2.2 Natures of the Schemes ................................................................. iii E2.3 Types of the Schemes.................................................................... iii E2.4 Types of Taps................................................................................. iii E2.5 Water Efficiency Grading for Non-mixer Taps ................................ iv E2.6 Test Parameters and Methodology for Non-mixer Taps ..................v E2.7 Recommended Water Efficiency Grade for Non-mixer Taps ...........v E2.8 Other Concerns for Non-mixer Taps............................................... vi E2.9 Water Efficiency Grading for Mixer Taps .......................................viii E2.10 Test Parameters and Methodology for Mixer Taps......................... ix E2.11 Recommended Water Efficiency Grade for Mixer Taps...................x E2.12 Other Concerns for Mixer Taps ...................................................... xi

E3 Urinals ......................................................................................................xiii E3.1 Overview of Oversea Technical Standards....................................xiii E3.2 Natures of the Schemes ................................................................xiii E3.3 Types of the Schemes...................................................................xiii E3.4 Types of Urinals.............................................................................xiii E3.5 Water Efficiency Grading .............................................................. xiv E3.6 Test Parameters and Methodology............................................... xiv E3.7 Recommended Water Efficiency Grade......................................... xv E3.8 Other Concerns ............................................................................. xv

E4 Toilets/Lavatory Equipment .....................................................................xvii E4.1 Overview of Oversea Technical Standards...................................xvii E4.2 Natures of the Schemes ...............................................................xvii E4.3 Types of the Schemes..................................................................xvii E4.4 Types of Toilets/Lavatory Equipment............................................xvii E4.5 Water Efficiency Grading .............................................................xviii E4.6 Test Parameters and Methodology..............................................xviii E4.7 Recommended Water Efficiency Grade........................................ xix

E5 Showers ................................................................................................... xx E5.1 Overview of Oversea Technical Standards.................................... xx E5.2 Natures of the Schemes ................................................................ xx E5.3 Types of the Schemes................................................................... xx E5.4 Types of Showers .......................................................................... xx E5.5 Water Efficiency Grading ............................................................... xx E5.6 Test Parameters and Methodology............................................... xxi E5.7 Recommended Water Efficiency Grade........................................xxii E5.8 Other Concerns ...........................................................................xxiii

E6 Summary of the Recommended Grades for Various Water Saving Devices...................................................................................................xxiv

Part 1 – Preamble...................................................................................... 1 1 Description of the Project ...........................................................................2

1.1 Background .....................................................................................2 1.2 Objectives........................................................................................2


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Part 2 – Development of the Technical Standards and Specifications .................................................................................. 3 2 Taps ...........................................................................................................4

2.1 Overview..........................................................................................4 2.2 Natures of the Schemes ..................................................................5 2.3 Types of the Schemes.....................................................................5 2.4 Types of Taps..................................................................................9 2.5 Previously Proposed Water Efficiency Grading .............................10 2.6 Water Efficiency Grading for Non-mixer Taps ...............................11 2.7 Test Parameters for Non-mixer Taps.............................................13 2.8 Recommended Water Efficiency Grade for Non-Mixer Taps .........13 2.9 Other Concerns for Non-mixer Taps..............................................14 2.10 Water Efficiency Grading for Mixer Taps .......................................17 2.11 Test Parameters for Mixer Taps ....................................................18 2.12 Recommended Water Efficiency Grade for Mixer Taps.................19 2.13 Other Concerns for Mixer Taps .....................................................20

3 Urinals ......................................................................................................22 3.1 Overview........................................................................................22 3.2 Natures of the Schemes ................................................................22 3.3 Type of the Schemes.....................................................................25 3.4 Types of Urinals.............................................................................25 3.5 Water Efficiency Grading ...............................................................27 3.6 Test Parameters ............................................................................28 3.7 Recommended Water Efficiency Grade.........................................29 3.8 Other Concerns for Urinals ............................................................30

4 Toilets/lavatory Equipment .......................................................................31 4.1 Overview........................................................................................31 4.2 Natures of Schemes ......................................................................31 4.3 Type of Schemes...........................................................................32 4.4 Types of Toilets/Lavatory Equipment.............................................35 4.5 Water Efficiency Grading ...............................................................35 4.6 Test Parameters ............................................................................37 4.7 Recommended Water Efficiency Grade.........................................38 4.8 Other Concerns for Toilets/Lavatory Equipment............................39

5 Showers ...................................................................................................40 5.1 Overview........................................................................................40 5.2 Nature of Schemes........................................................................40 5.3 Types of Schemes.........................................................................43 5.4 Types of Showers ..........................................................................43 5.5 Water Efficiency Grading ...............................................................43 5.6 Test Parameters ............................................................................45 5.7 Recommended Water Efficiency Grade.........................................46 5.8 Other Concerns .............................................................................47

Part 3 – Technical Standards and Specifications................................. 49 6 Proposed Technical Standard for Taps ....................................................50

6.1 Scope ............................................................................................50 6.2 Water Efficiency Grading for Non-mixer Taps ...............................50 6.3 Water Efficiency Grading for Mixer Taps .......................................50 6.4 Test Parameters and Methodology................................................51 6.5 Testing Laboratories and Accreditation Bodies .............................51


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7 Proposed Technical Specification of Taps................................................53 7.1 Recommended Water Efficiency Grade for Non-Mixer Taps .........53 7.2 Recommended Water Efficiency Grade for Mixer Taps.................55 7.3 Technical Specifications of Non-mixer and Mixer Taps on

Materials ........................................................................................57 7.4 Technical Specification of Non-mixer and Mixer Taps on

Workmanship.................................................................................60 8 Proposed Technical Standard for Urinals.................................................61

8.1 Scope ............................................................................................61 8.2 Water Efficiency Grading ...............................................................61 8.3 Test Parameters and Methodology................................................62 8.4 Testing Laboratories and Accreditation Bodies .............................62

9 Proposed Technical Specification of Urinals ............................................64 9.1 Recommended Water Efficiency Grade.........................................64 9.2 Technical Specification on Materials..............................................64 9.3 Technical Specification on Workmanship ......................................66

10 Proposed Technical Standard for Toilets/lavatory Equipments ................68 10.1 Scope ............................................................................................68 10.2 Water Efficiency Grading ...............................................................68 10.3 Test Parameters and Methodology................................................68 10.4 Testing Laboratories and Accreditation Bodies .............................69

11 Proposed Technical Specification of Toilets/lavatory Equipment .............71 11.1 Recommended Water Efficiency Grade.........................................71 11.2 Technical Specification on Materials..............................................71 11.3 Technical Specification on Workmanship ......................................74

12 Proposed Technical Standard for Showers ..............................................76 12.1 Scope ............................................................................................76 12.2 Water Efficiency Grading ...............................................................76 12.3 Test Methodology ..........................................................................76 12.4 Testing Laboratories and Accreditation Bodies .............................77

13 Proposed Technical Specification of Showers..........................................79 13.1 Recommended Water Efficiency Grade.........................................79 13.2 Technical Specification on Materials..............................................79

14 Summary of the Recommended Grades for Various Water Saving Devices.....................................................................................................81 14.1 Summary of the Recommended Grades .......................................81

Part 4 – Comments from Various Bodies.............................................. 84 15 Comments from Various Bodies...............................................................85

15.1 Overview........................................................................................85 15.2 Details of Comments .....................................................................85

Part 5 – References ................................................................................ 91 16 References ...............................................................................................92

16.1 Literature References ....................................................................92 16.2 Key International Standards ..........................................................92

Appendix 1 Extracts of Pressure Drop Test on Water Efficient Showers


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Part 1 – Preamble



1 Description of the Project

1.1 Background

1.1.1 The scope of the original project was to provide recommendations for the Water Supplies Department (WSD) water saving project which was focused on government buildings, municipal venues and schools only. After completion of the original project, an additional project was proposed to extend the study to develop recommendations of water saving devices for new buildings.

1.1.2 In the original project, oversea technical standards of water saving devices were

reviewed so that technical standards, including the water efficiency grading system, the test parameters and testing methodology, for Hong Kong context were developed. Technical specifications, especially the recommended water efficiency grades, for different types of water saving devices were also proposed for the WSD’s water saving project.

1.2 Objectives

1.2.1 In this extended project, study has been conducted to review if any modifications to the previous findings and recommendations developed in the original project were needed for the application of water saving devices in the new buildings. The scope of study has been agreed to confine to: (a) water saving devices used in toilets and bathrooms, excluding disabled toilets,

in all new buildings except hospitals; and (b) kitchen taps in all new buildings except hospitals. As “new buildings” will include domestic and non-domestic buildings, the scope of this study will cover all the general toilets and bathrooms, plus kitchen taps for new residential establishments, hotels or similar establishments, schools, offices, shops, commercial establishments, clinics, car parks and factories, etc.



Part 2 – Development of the Technical Standards and Specifications



2 Taps

2.1 Overview

2.1.1 Many types of water conservation appliances, such as household appliances and plumbing appurtenance, are available in the worldwide market. Different types of labeling schemes are implemented for different types of water conservation appliances around the world. For example, EU developed a “European Eco-label” scheme for dishwashers and washing machines.

2.1.2 Some countries recognize water saving taps using “Eco-label” schemes. A summary of these schemes are listed in Table 2.1.

Table 2.1 Eco-label Schemes for Taps in Overseas

Location Name Performance Requirements Taiwan 省水標章 1 L/min ≤f ≤ 9 L/min @ 0.1 MPa

Japan Eco Mark “Flow-control valve” or “Faucet with built-in flow control valve” When the handle is fully opened, the proper flow shall be in the range of 5-8 L/min at a water pressure of 0.1 MPa and more and at 0.7MPa and lower. “Aerator cap” or “Faucet with aerator function”: (1) At a water pressure of 0.1 MPa or more and at a water pressure of 0.7 MPa or less, the discharge shall not be more than 80% of that of the tap without the aerator cap. (2) The discharge shall not be less than 5 liters/min at a water supply pressure of 0.1 MPa with a fully opened lever. “Automatic tap (with self-generation function)” or “Automatic tap (AC 100V type)”: At water pressure of 0.1MPa and higher, and at 0.7MPa and lower, discharge volume shall not exceed 5 L/min.

Canada Eco Label A maximum flow rate of 6.4 L/min at 4.1 kg/cm2 ( 1.7 USgpm at 60 psi), if intended for use in lavatories; A maximum flow rate of 6.4 L/min at 4.1 kg/cm2 ( 1.7 USgpm at 60 psi), if intended for use in kitchens

Korea KOECO For Kitchen: f ≤ 9.0 L/min @ 98 kPa For face wash: f ≤ 7.5 L/min @ 98 kPa For shower,shower/tub: f ≤ 9.5 L/min @ 98 kPa For others: f ≤ 9.5 L/min @ 98 kPa

2.1.3 In Mainland China, requirements of different water saving devices for plumbing appurtenance are specified in the national standard for construction industries: CJ 164-2002: Domestic water saving devices (CJ 164-2002: 中華人民共和國城鎮建設

行業標準節水型生活用水器具).

2.1.4 Water efficiency grading schemes of taps have been implemented or being planned in overseas. Several schemes have been well established in Australia,



New Zealand, Singapore, U.K. and U.S. Therefore, this review focuses on the standards established from these five countries. Details of the standards are listed in Table 2.2.

2.2 Natures of the Schemes

2.2.1 The schemes established in Australia, New Zealand and Singapore are mandatory and all the taps specified under these schemes must be registered, rated and labeled according to the requirements of the standards. On the other hand, the schemes established in U.K. and U.S. are implemented on a voluntary basis. As an initiative to promote water saving in Hong Kong, the technical standard established in this project will be on a voluntary basis.

2.3 Types of the Schemes

2.3.1 The schemes established in Australia, New Zealand and Singapore are of grading type. Under these schemes, all the taps are rated to different grades of water efficiency in accordance with the flow rate test results and are subject to the compliance with other specified performance requirements. Labels will be affixed to the taps so as to indicate their water consumption levels and efficiency grading.

2.3.2 The schemes established in U.K. and U.S. are of recognition type. Verification

water efficiency labels would be fixed to those taps that have met the specified water flow rate requirement and are in compliance with the other specified performance criteria. Only one flow rate is specified in this type of schemes. It may not be flexible enough if different types of taps have to be used under different situations.

2.3.3 In view of the higher flexibility, a grading system is recommended for the proposed

technical standard for taps in Hong Kong.



Table 2.2 Details of the Oversea Standards and Proposed Hong Kong Standard for Taps Water Efficiency Grading

Country Scheme Nature

Label Type Types of Tap Water Consumption

Band 1 Band 2 Band 3 Band 4 Band 5 Band 6 Band 7 Test Parameters Note

Australia Mandatory (Under implementation started in July 2006)

Grading type with " " star

Any tap or tap outlet except a) solely for use over a bath; or b) part of an appliance such as a chilled or boiling water dispenser.

Nominal flow rate (L/min) of AS/NZS 3718

Zero Star flow rate > 16.0 or failing the performance requirements

1 Star 12 < flow rate ≤ 16

2 Stars 9 < flow rate ≤ 12

3 Stars 7.5 < flow rate ≤ 9

4 Stars 6 < flow rate ≤ 7.5


6 Stars flow rate ≤ 4.5

AS/NZS 3718 a) Plastic materials used for plastic-bodied taps b) Hydraulic strength test c) Watertightness under pressure d) Nominal flow rate e) Torque of fabricated joints f) Torque of head to body g) Endurance test for taps and tap components

(1)

New Zealand

Mandatory (Under development)


Basin, ablution trough, kitchen sink or laundry tub


Zero Star flow rate >16.0 or failing the performance requirements




4 Stars 6 < flow rate ≤ 7.5


6 Stars flow rate ≤ 4.5

AS/NZS 3718 a) Nominal flow rate b) Watertightness under pressure c) Endurance d) Hydraulic strength test

(1)



Water Efficiency Grading




Shower taps and mixers (except concealed shower taps and mixers & concealed bath/shower taps and mixers)

Nominal flow rate (L/min) shall be the mean of the average flow rates obtained at the following dynamic flow pressures: 150 kPa, 250 kPa, 350 kPa, 450 kPa and 500 kPa

Zero Tick flow rate > 9

Good (1 Tick) 7 < flow rate ≤ 9

Very Good (2 Ticks) 5 < flow rate ≤ 7

Excellent (3 Ticks) flow rate ≤ 5

Not applicable

Not applicable

Not applicable

Flow rate, in accordance with specific standards

(2)

Basin taps and mixers






Not applicable

Not applicable

Not applicable


(3)

Singapore Mandatory Grading type with " � " tick

Sink/bib taps and mixers






Not applicable

Not applicable

Not applicable


(4)

UK Voluntary Recognition type (with symbolic indication of flow rate)

Taps for use with wash basins and bidets

Nominal flow rate (L/min), measurement method described in Guide to Test for the BMA WEPL Scheme

≤ 6 Not applicable

Not applicable

Not applicable

Not applicable

Not applicable

Not applicable

Modified Clause 10.2.3 of Pr EN 200 revision (dated 2007-04) Flow rate



Water Efficiency Grading Country

Scheme Nature



US WaterSense Parnership programme by US EPA

Recognition type

Lavatory faucets and lavatory faucet accessories

The flow rate (gpm) in accordance with ASME A112.18.1/CSA B125.1

flow rate ≤ 1.5 (5.7 L/min)

Not applicable

Not applicable

Not applicable

Not applicable

Not applicable

Not applicable

ASME A112.18.1/CSA B125.1 Flow rate

(5)

Non-mixer taps Nominal flow rate (L/min) of AS/NZS 3718

Level 1 flow rate ≤ 2.0

Level 2 2.0 < flow rate ≤ 4.0


Level 4 flow rate > 6.0

Not applicable

Not applicable

Not applicable

AS/NZS 3718 a) Nominal flow rate b) Endurance

(6) Hong Kong Grading type

Mixer taps Nominal flow rate (L/min) of AS/NZS 3718




Level 4 flow rate > 9.0

Not applicable

Not applicable

Not applicable

AS/NZS 3718 a) Nominal flow rate b) Endurance

(6) (7)

Notes: (1) If tap equipment has an effective automatic shut-off device, its water efficiency grading is upgraded by one grade (if any).

(2) Flow rate is determined in accordance with following standards For shower taps (cold water only), self-closing-delayed-action shower taps, sensor (including self-closing-delayed-action) shower taps or combination shower tap assemblies: Annex A of SS448 : Part 3 : 1998 or Section 10.3 of BS5412 : 1996 For mechanical shower mixers with a single or separate control device for adjusting flow rate and temperature: Section 10 of BS EN 817 : 2008 or Section 10 of BS EN 817 : 1998 (For tests done before 1 Sep 09 only) For thermostatic mixers: Section 3, Clause 12 of BS 1415:Part 2:1986 or Section 10 of BS EN 1287:1999 For Excellent or 3 Ticks rating, this lowest average flow rate shall not be less than 4.5 litres/min.

(3) Flow rate is determined in accordance with following standards: For pillar basin taps, self-closing-delayed-action basin taps, sensor (including self-closing-delayed-action) basin taps or combination basin tap assemblies: Annex A of SS448 : Part 3 : 1998 or Section 10.3 of BS5412 : 1996 For mechanical basin mixers with a single or separate control device for adjusting flow rate and temperature: Section 10 of BS EN 817 : 2008 or Section 10 of BS EN 817 : 1998 (For tests done before 1 Sep 09) For thermostatic mixers: Section 3, Clause 12 of BS 1415:Part 2:1986 or Section 10 of BS EN 1287:1999 For Excellent or 3 Ticks rating, this lowest average flow rate shall not be less than 1.5 litres/min.

(4) Flow rate is determined in accordance with following standards: For bib taps, sink taps (cold water only), sensor sink taps or combination sink tap assemblies: Annex A of SS448 : Part 3 : 1998 or Section 10.3 of BS5412 : 1996 For mechanical sink mixers with a single or separate control device for adjusting flow rate and temperature: Section 10 of BS EN 817 : 2008 or Section 10 of BS EN 817 : 1998 (For tests done before 1 Sep 09) For thermostatic mixers: Section 3, Clause 12 of BS 1415:Part 2:1986 or Section 10 of BS EN 1287:1999 For Excellent or 3 Ticks rating, this lowest average flow rate shall not be less than 2.5 litres/min or sink taps and 3.5 litres/min for bib taps.

(5) A lavatory tap is also considered to meet this flow rate requirement if it is equipped with a lavatory tap accessory that meets this requirement.

(6) An extra merit is proposed to the water taps with automatic shut-off mechanism

(7) An extra merit is proposed to the mixer taps that can achieve a nominal flow rate ≤ 2 L/min



2.4 Types of Taps

2.4.1 In this study, “taps” means any tap or tap outlet that is for use over a basin and kitchen sink, regardless of the operating mechanism. Note: Tap types include combination taps, mixing taps, electronic taps/sensor taps; This standard does not apply to any tap or tap outlet that is: (a) solely for use over a bath; or (b) part of an appliance such as a chilled or boiling water dispenser.

2.4.2 The types of taps specified in the schemes of Australia and New Zealand are

similar as both schemes are implemented based on the same standard. Their standards are applicable to all types of taps except for those used over a bath and places other than basin, ablution trough, kitchen sink or laundry tub. It is reasonable because a low flow rate for a tap used over a bath does not necessarily imply any water saving as the amount of water to fill up the bath does not change.

2.4.3 Similar types of taps are covered by the scheme implemented in Singapore. However, the scheme is implemented under three different standards for three different groups of taps according to their applications - Shower taps and mixers; - Basin taps and mixers; and - Sink/bib taps and mixers It has set a more stringent flow rate requirement on sink/bib taps and mixers because the amount of water consumed by these sink/bib taps and mixers occupies a significant portion in the total domestic water consumption.

2.4.4 The whole U.K. scheme is applied on bathroom products. Therefore, the U.K.

scheme is only applicable to taps and combination tap assemblies for use with wash basins and bidets.

2.4.5 Similarly, the U.S. scheme is only applicable to lavatory taps and lavatory taps

accessories. 2.4.6 The proposed Hong Kong technical standard is developed mainly for the purpose

of the application of water saving devices in the new buildings. The scope of study has been agreed to confine to: (a) water saving devices used in toilets and bathrooms, excluding disabled

toilets, in all new buildings except hospitals; and (b) kitchen taps in all new buildings except hospitals. As “new buildings” will include domestic and non-domestic buildings, the scope of this study will cover all the general toilets and bathrooms, plus kitchen taps for residential establishments, hotels or similar establishments, schools, offices, shops, commercial establishments, clinics, car parks and factories, etc.

2.4.7 The proposed Hong Kong technical standard shall cover all types of taps and only exclude the taps over a bath similar to the standards in Australian/New Zealand.



2.5 Previously Proposed Water Efficiency Grading

2.5.1 The water efficiency grading proposed for taps in the previous study is illustrated in Table 2.3.

Table 2.3 Proposed Water Efficiency Grading for Taps in the Previous Study




Level 3 (Good) 6.0 < f ≤ 9.0

Level 4 f > 9.0 2.5.2 The grading was developed with reference to various oversea standards,

especially the standards of Australia/New Zealand which has been well established, so that products in compliance with the oversea water efficiency standards can easily follow the proposed Hong Kong standard.

2.5.3 However, many mixer taps for domestic uses will be connected to domestic water

heaters in order to provide hot water supply. Since many domestic water heaters have minimum flow rate requirements to trigger their operation, there is possibility that water efficiency mixer taps with the flow rates restricted may not be compatible to some domestic water heaters, especially when the supply pressure of the water main is not high. Whereas, non-mixer type water taps do not have this technical problem because they are normally not connected to any water heaters. With no technical constraints, it is possible for non-mixer taps to achieve greater water efficiency than the mixer taps. Hence, there are views to separate the water efficiency grading system for the non-mixer taps and mixer taps.

2.5.4 In the previously proposed water efficiency grading, if the tap equipment has an

effective automatic shut-off device, it is also recommended to upgrade its water efficiency grading by one level (if any) in order to appreciate the resulted water saving by preventing any non-operative loss of water. Nevertheless, some views opine that it may lead to confusion to the public about the water efficiency grading system. Also, if the water efficiency taps are used in reasonable manner, the actual water saving achieved by an automatic shut-off device may not be substantial enough to upgrade the water efficiency grading by one level. In this regard, it is proposed to grant an extra merit to those mixer taps that are equipped with some automatic shut-off mechanisms instead of upgrading their water efficiency levels.

2.5.5 The two revised water efficiency grading systems for non-mixer taps and mixer

taps respectively as compared with the different oversea standards are shown in Figure 2.1. Details of the rationales for the two revised systems are described in the following paragraphs.



Figure 2.1 Oversea Standards (Australia/New Zealand and Singapore) and Proposed

Hong Kong Standard for Taps

2.6 Water Efficiency Grading for Non-mixer Taps

2.6.1 Figure 2.1 illustrates a general overview of the water efficiency grading in different standards. It is recommended to adopt a water efficiency grading scale consistent to the oversea standards so that products in compliance with the oversea water efficiency standards can easily follow the proposed Hong Kong standard.

2.6.2 Unlike the mixer taps that may have compatibility problems with the domestic

water heaters, non-mixer taps can actually achieve much lower flow rates than the mixer taps. As non-mixer taps are mostly installed over basins, the Singaporean standard for basin tap/mixer is benchmarked. As illustrated by the Singaporean standard, the best water efficiency basin tap/mixer can achieve flow rates as low as < 2 L/min.

2.6.3 Based on the information as of 19th February 2010 posted in the webpage of PUB,

Singapore as shown in Table 2.4, there are 178 basin taps/mixers and 476 sink taps/mixers registered as the best water efficiency taps with flow rates <2 L/min and <4 L/min respectively. This proves that taps of higher water efficiency are technically feasible and available in the market.



Table 2.4 Registry of Water Efficiency Taps in Singapore

Types of Taps No. of Ticks

Flow Rate (L/min) (1) Number of Registered Taps (as of 19th February 2010)

3 f ≤ 2 178 2 2 < f ≤ 4 304 1 4 < f ≤ 6 300

Basin Tap/Mixer

0 f > 6 516 3 f ≤ 4 476 2 4 < f ≤ 6 212 1 6 < f ≤ 8 54

Sink Tap/Mixer

0 f > 8 681

Remarks: (1) Flow rates are determined according to the respective Singaporean standards. 2.6.4 As shown in Figure 2.1, with reference to the oversea standards for taps, the water

efficiency grading of the proposed Hong Kong standards will be defined as follows: Level 4 - ordinary non-mixer taps equivalent to zero tick in the Singaporean

standard for basin tap/mixer Level 3 - Non-mixer taps with minimal water saving, equivalent to 1 tick in the

Singaporean standard for basin tap/mixer Level 2 - Non-mixer taps equivalent to 2 ticks in the Singaporean standard for

basin tap/mixer Level 1 - The best non-mixer taps equivalent to 3 ticks in the Singaporean

standard for basin tap/mixer 2.6.5 The water saving performance of the various water efficiency levels are ranked as

“Excellent”, “Very Good” or “Good”. 2.6.6 In the previously proposed water efficiency grading, if the tap equipment has an

effective automatic shut-off device, it is also recommended to upgrade its water efficiency grading by one level (if any) in order to appreciate the resulted water saving by preventing any non-operative loss of water. Nevertheless, some views opine that it may lead to confusion to the public about the water efficiency grading system. Also, if the water efficiency taps are used in a reasonable manner, the actual water saving achieved by an automatic shut-off device may not be substantial enough to upgrade the water efficiency grading by one level. In this regard, it is proposed to grant an extra merit to those mixer taps that are equipped with some automatic shut-off mechanisms instead of upgrading their water efficiency levels.

2.6.7 The proposed water efficiency grading for non-mixer taps is shown in Table 2.5

and illustrated in Figure 2.1.



Table 2.5 Water Efficiency Grading of the Proposed Hong Kong Standard for Taps




Level 3 (Good) 4.0 < f ≤ 6.0

Level 4 f > 6.0

# An extra merit is proposed to the water taps with automatic shut-off mechanism. 2.7 Test Parameters for Non-mixer Taps

2.7.1 The WELS of Australia covers the most comprehensive test parameters and distribution of ranges in the water efficiency grading. However, not all the test parameters in the Australia/New Zealand standards are related to the water saving performance of the tap. Flow rate is the key measurement of the water saving taps in all oversea standards and another parameter is the endurance of the flow controller. Therefore, the proposed standard for Hong Kong will only include the tests on the nominal flow rate and the endurance of taps.

2.7.2 The nominal flow rates of the water taps shall be tested in accordance with the

testing methodology in AS/NZS 3718:2005. The water taps are then rated to different levels according to the nominal flow rate test results subject to the compliance with other performance requirements as shown in Table 2.6.

Table 2.6 Performance Requirements for Water Taps





2.8 Recommended Water Efficiency Grade for Non-Mixer Taps

2.8.1 With reference to the assessment criteria used in the previous study, the recommended grade for new buildings is determined based on the following assessment criteria: - Water saving performance; - Technical applicability; and - Availability in local market The factor of cost implication is not considered in this study since the prices of the water efficiency non-mixer taps may vary substantially when they are getting popular in Hong Kong.

2.8.2 In general, Level 1 will be recommended from the perspective of water saving

unless there are technical applicability problems or inadequate local availability hindering the use of Level 1 non-mixer taps.



2.8.3 As demonstrated from the registration of water efficiency taps in Singapore, taps with flow rates <2 L/min are technically feasible and available in the market although they may not be currently common in Hong Kong.

2.8.4 However, there is one technical issue that needs to be addressed. The flow rates

of taps are specified in terms of nominal flow rates which are the average values of the measured water flow rates under pressure of 150 kPa, 250 kPa and 350 kPa. For the highest floors of a building, if fresh water is supplied from the rooftop fresh water tank by gravity without any booster pump, the water supply pressure can be lower than 150kPa. In order to make sure that the actual flow rates of the water efficiency taps would not be far below their specified nominal flow rates, it is recommended to explicitly specify a minimum water supply pressure of at least 150 kPa to be maintained at the cold water inlet of the individual water heater in all new buildings.

2.8.5 As shown in Table 2.7, it is recommended to use Level 1 (Excellent) water

efficiency non-mixer taps in the toilets of all new buildings except hospitals.

Table 2.7 Recommended Grade of Water Efficiency Non-mixer Taps Assessment Criteria Level 1 Level 2 Level 3 Water saving performance ��



Recommended grade Excellent Very Good Good 2.9 Other Concerns for Non-mixer Taps

2.9.1 Some people may think that hand washing may not be so effective when using a water efficiency tap and would concern about the hand hygiene. The hand hygiene guidelines given by both the World Health Organization and the Centre for Health Protection of Hong Kong only suggest rinsing hands thoroughly under running water. They do not specify how much water to be used or how long for the rinsing. Therefore, technically, a water efficiency tap will not impair the hand hygiene during hand washing provided that sufficient amount of running water is used. In fact, there are no reports from overseas, like Singapore or Australia, saying that water efficiency taps will affect hand hygiene. However, users may consider lower levels of water efficiency taps if they have concerns about hygiene in some critical applications, like clinics or elderly centres.

2.9.2 Users shall also be reminded that as the flow rates of the water efficiency taps will

definitely be smaller than those of ordinary taps, longer time will be required by the water efficiency taps to fill up containers, like kettles or buckets. Users may consider using taps of lower water efficiency levels if the afore-mentioned issue is very critical to their operations.

2.9.3 Users shall also consider using non-mixer taps with automatic shut-off mechanism

and an extra credit will be given to recognize the additional benefit in water saving. 2.9.4 Taps equipped with energy saving features, such as solar panels to drive the

electronic sensors, are available in the market. Although the taps may not be totally self-powered, it can still enhance the life of the batteries installed in the taps, thereby reducing the environmental issue of battery disposal. The energy saving



features will not improve the water efficiency grading of the taps. However, from the environmental perspective, these taps with energy saving features shall be encouraged to use.

2.9.5 In respect of the taps with automatic shut-off devices, taps with maximum closing

time of no more than 1 min are recommended. 2.9.6 The recommended grades of water efficiency of non-mixer taps for different

applications are summarized in Table 2.8.



Table 2.8 Recommended Grades of Non-mixer Taps for Various Applications

Level 1# Excellent

(f ≤ 2.0 L/min)

Level 2# Very Good

(2.0 L/min < f ≤ 4.0 L/min)

Level 3# Good

(4.0 L/min < f ≤ 6.0 L/min)

- No technical constraints; - Used in public places; - For general personal hygiene purpose; - Mainly for hand washing; - Not recommended for high volume



- No technical constraints; - Used in private and public facilities; - For general personal hygiene purpose; - For high volume usage such as


- For facilities that involve physical activities such as sports which lead to frequent and high volume usage;


- Examples: Toilets for residential premises, including dormitories of boarding schools and universities, performance venues (e.g. town halls, cultural centres, theatres etc.), schools and leisure venues (e.g. sports centres, playgrounds, sports stadiums, swimming pools etc.


hygienic condition; - For higher personal hygiene


cleansing of dirty substances to remove germs;


# An extra merit is proposed to the water taps with automatic shut-off mechanism



2.10 Water Efficiency Grading for Mixer Taps

2.10.1 Figure 2.1 illustrates a general overview of the water efficiency grading in different standards. It is recommended to adopt a water efficiency grading scale consistent to the oversea standards so that products in compliance with the oversea water efficiency standards can easily follow the proposed Hong Kong standard.

2.10.2 Mixer taps are normally associated with some water heating systems to provide

hot water supply. The water efficiency grading for mixer taps shall be designed with due consideration of the possible compatibility problems when water efficiency mixer taps are connected to the domestic water heaters.

2.10.3 According to the compatibility test, the flow-controlled water heaters, no matter if

town gas, LPG or electricity is used, have minimum flow rate requirement of about 3 L/min. Whereas, the pressure-controlled water heaters, again no matter if town gas, LPG or electricity is used, normally require higher minimum water flow rates than the flow-controlled ones to trigger the operations. Their values vary from 3 L/min to about 5.8 L/min. In the case of storage type water heaters, no minimum flow rate is required for their operation.

2.10.4 As shown in Figure 2.1, with reference to the oversea standards for taps, the water

efficiency grading of the proposed Hong Kong standards will be defined as follows: Level 4 - ordinary non-mixer taps equivalent to zero tick in the Singaporean

standard for basin tap/mixer Level 3 - Non-mixer taps with minimal water saving, equivalent to 1 tick in the

Singaporean standard for basin tap/mixer Level 2 - Non-mixer taps equivalent to 2 ticks in the Singaporean standard for

basin tap/mixer Level 1 - The best non-mixer taps equivalent to 3 ticks in the Singaporean

standard for basin tap/mixer 2.10.5 The water saving performance of each level are represented by naming of

“Excellent”, “Very Good” and “Good”. 2.10.6 In the previously proposed water efficiency grading, if the tap equipment has an

effective automatic shut-off device, it is also recommended to upgrade its water efficiency grading by one level (if any) in order to appreciate the resulted water saving by preventing any non-operative loss of water. Nevertheless, some views opine that it may lead to confusion to the public about the water efficiency grading system. Also, if the water efficiency taps are used in reasonable manner, the actual water saving achieved by an automatic shut-off device may not be substantial enough to upgrade the water efficiency grading by one level. In this regard, it is proposed to grant an extra merit to those mixer taps that are equipped with some automatic shut-off mechanisms instead of upgrading their water efficiency levels.

2.10.7 Based on the above rationales, the water efficiency grading as listed in Table 2.9

and illustrated in Figure 2.1 is proposed for mixer taps used in new buildings.



Table 2.9 Water Efficiency Grading for Mixer Taps




Level 3 (Good) 7.0 < f ≤ 9.0

Level 4 f > 9.0


# An extra merit is proposed to the water taps with automatic shut-off mechanism. 2.10.8 With the proposed water efficiency levels for mixer taps, it is anticipated that no

serious compatibility problem with the water heaters shall be encountered if the public is aware of the types of water heaters that each category of mixer taps are compatible to.

2.10.9 Besides, when storage type water heaters or centralized water heating systems

are used, the compatibility problem between the water efficiency mixer taps and the water heaters no longer exists. There is room to pursue higher water efficiency than just <5 L/min. This is particularly true for those high water consuming non-domestic users, like hotels, hostels, sports centers, etc., where centralized water heating systems are used. In order to encourage the use of the best water efficiency mixer taps in the market, an extra credit is proposed for mixer taps that can achieve nominal flow rates <2 L/min. This water efficiency level will be equivalent to the best water efficiency level achieved for non-mixer taps as shown in Figure 2.1.

2.11 Test Parameters for Mixer Taps

2.11.1 The WELS of Australia covers the most comprehensive test parameters and distribution of ranges in the water efficiency grading. However, not all the test parameters in the Australia/New Zealand standards are related to the water saving performance of the tap. Flow rate is the key measurement of the water saving taps in all oversea standards and another parameter is the endurance of the flow controller. Therefore, the proposed standard for Hong Kong will only include the tests on the nominal flow rate and the endurance of taps.

2.11.2 The nominal flow rates of the mixer taps shall be tested in accordance with the

testing same methodology as that for non-mixer taps (with reference to AS/NZS 3718:2005). The mixer taps are then rated to different grades according to the nominal flow rate test results subject to the compliance with other performance requirements as shown in Table 2.10.



Table 2.10 Performance Requirements for Mixer Taps




2.12 Recommended Water Efficiency Grade for Mixer Taps

2.12.1 With reference to the assessment criteria used in the previous study, the recommended grade for new buildings is determined based on the following assessment criteria: - Water saving performance; - Technical applicability; and - Availability in local market The factor of cost implication is not considered in this study since the prices of the water efficiency non-mixer taps may vary substantially when they are getting popular in Hong Kong.

2.12.2 In general, Level 1 is recommended from the perspective of water saving unless

there are technical applicability problems or inadequate local availability hindering the use of Level 1 mixer taps.

2.12.3 Based on the compatibility test results, Level 1 water efficiency mixer taps will be

recommended if storage type water heaters or centralized water heating systems can be used in the new buildings. Whereas, if instantaneous type water heaters have to be used, it is recommended to use flow-controlled type water heaters and Level 2 water efficiency mixer taps will be compatible to these water heaters. However, if only pressure-controlled type instantaneous water heaters can be used, it will be advisable to install Level 3 water efficiency mixer taps in order to avoid any compatibility problem between the taps and the water heaters.

2.12.4 As shown in Table 2.11, water efficiency mixer taps of different levels will be

recommended according to the types of domestic water heaters used in the new buildings.



Table 2.11 Recommended Grade of Water Efficiency Mixer Taps

Assessment Criteria

Level 1 Level 2 Level 3 Level 4

Water saving performance

��

Technical applicability


water heaters


and flow-controlled

water heaters

Applicable to storage type, flow-

controlled and pressure-controlled

water heaters

Applicable to all types of

water heaters

Availability in local market

��

Recommended grade

Excellent Very Good Good Ordinary

2.13 Other Concerns for Mixer Taps

2.13.1 The water supply pressure at the cold water inlet of the individual water heater is maintained at no less than 150 kPa.

2.13.2 Similar to non-mixer taps, users may consider lower levels of water efficiency taps

if they have concerns about hygiene in some critical applications, like clinics or elderly centres.



2.13.4 When storage type water heaters or centralized water heating systems are used,

users may consider using mixer taps with nominal flow rates of <2 L/min so as to get an extra credit.

2.13.5 Users shall also consider using mixer taps with automatic shut-off mechanism and

an extra credit will be given to recognize the additional benefit in water saving. 2.13.6 The recommended grades of water efficiency of non-mixer taps for different

application are summarized in Table 2.12.



Table 2.12 Recommended Grades of Mixer Taps for Various Applications Level 1*, # Excellent

(f ≤ 5.0 L/min)

Level 2# Very Good

(5.0 L/min < f ≤ 7.0 L/min)

Level 3# Good

(7.0 L/min < f ≤ 9.0 L/min)






















3 Urinals

3.1 Overview

3.1.1 Many types of water conservation appliances, such as household appliances and plumbing appurtenance, are available in the worldwide market. Different types of labelling schemes are implemented for different types of water conservation appliances around the world. For example, EU developed a “European Eco-label” scheme for dishwashers and washing machines.

3.1.2 Some countries recognize water saving urinals using “Eco-label” schemes. A summary of these schemes are listed in Table 3.1.

Table 3.1 Eco-label Schemes for Urinals in Overseas

Location Name Performance Requirements Taiwan 省水標章 1 L ≤ f ≤ 3 L

Japan Eco Mark f ≤ 2.5 L @ 0.2 MPa

Korea KOECO Volume of water consumption under 2L @ 98 kPa

3.1.3 In Mainland China, requirements of different water saving devices for plumbing

appurtenance are specified in the national standard for construction industries: CJ 164-2002: Domestic water saving devices (CJ 164-2002: 中華人民共和國城鎮建設


3.1.4 Water efficiency grading scheme of urinals have been implemented or being planned in overseas. Several schemes have been well established in Australia, New Zealand, Singapore and U.S. Therefore, this review focuses on the standards established from these four countries. Details of the standards are listed in Table 3.2.

3.2 Natures of the Schemes

3.2.1 The schemes established in Australia, New Zealand and Singapore are mandatory and all the urinals specified under these schemes must be registered, rated and labeled according to the requirements of the standards. On the other hand, the scheme established in U.S. is implemented on a voluntary basis. As an initial initiative to promote water saving in Hong Kong, the technical standard established in this project will be on a voluntary basis.



Table 3.2 Details of the Overseas Standards and Proposed Hong Kong Standard for Urinals Water Efficiency Grading

Country Scheme Nature Label Type Water Consumption

Band 1 Band 2 Band 3 Band 4 Band 5 Band 6 Band 7 Test Parameters



Volume of discharge (L/single stall or L/600 mm width of continuous wall) of AS/NZS 3982

Zero Star • More than 2.5 serving a single stall or 4.0 for two stalls or equivalent width of continuous wall, or • failing the performance requirements, or • having an adjustable activation device with a sensitivity field greater than 300 mm from the front of the urinal, or • having a flushing control mechanism that flushs more than two stalls or equivalent width of continuous wall

1 Star • Not more than 4.0 serving two stalls or equivalent width of continuous wall, and • conscious, demand-driven or smart-demand operation

2 Stars • Not more than 2.5 serving a single stall or equivalent width of continuous wall, and • conscious, demand-driven or smart-demand operation


4 Stars • Not more than 1.5 serving a single stall or equivalent width of continuous wall, and • smart-demand operation


6 Stars • Not more than 1.0 serving a single stall or equivalent width of continuous wall, and • smart-demand operation with a urine-sensing device

AS/NZS 3982: a) Flushing test for slab and stall urinals b) Flushing test for single stall wall-hung urinals c) Splash test for urinals ATS 5200.004: e) Distortion and leakage tests f) Discharge test

New Zealand Mandatory (Under development)


Volume of discharge (L/single stall or L/600 mm width of continuous wall) of AS/NZS 3982

Zero Star • More than 2.5 serving a single stall or 4.0 for two stalls or equivalent width of continuous wall, or • failing the performance requirements, or • having an adjustable activation device with a sensitivity field greater than 300 mm from the front of the urinal, or • having a flushing control mechanism that flushs more than two stalls or equivalent width of continuous wall

1 Star • Not more than 4.0 serving two stalls or equivalent width of continuous wall, and • conscious, demand-driven or smart-demand operation





6 Stars • Not more than 1.0 serving a single stall or equivalent width of continuous wall, and • smart-demand operation with a urine-sensing device

AS/NZS 3982: a) Volume of water used for each flush b) Various flushing performance tests that assess the ability to clear the bowl or surfaces ATS 5200.004: c) Tests for leakage where it is likely to be persistent and result in significant water loss over the life of the product



Water Efficiency Grading Country Scheme Nature Label Type Water

Consumption Band 1 Band 2 Band 3 Band 4 Band 5 Band 6 Band 7 Test Parameters


Volume of discharge (L) - method determined by PUB, Singapore's national water agency

Zero Tick Not applicable

Good (1 Tick) 1 < flow rate ≤ 1.5

Very Good (2 Ticks) 0.5 < flow rate ≤ 1

Excellent (3 Ticks) flow rate ≤ 0.5 or waterless

Not applicable Not applicable Not applicable Requirements for Urinal Flush Valves under Water Efficiency Labelling Scheme (WELS) Flowrate (When flow rate ≤ 0.5: Dye test specified in Clause 10.5 of the ASME A112.19.2-2003 or Clause 8.5 of the ASME A112.19.2-2008/CSA B45.1-08)

US WaterSense Parnership programme by US EPA (Under development)

Recognition type

The average water consumption (gpf) in accordance with ASME A112.19.2 or IAPMO Z124.9

average water consumption ≤ 0.5 (1.9 L per flush)

Not applicable Not applicable Not applicable Not applicable Not applicable Not applicable ASME A112.19.2 or IAPMO Z124.9 Average volume consumption

Hong Kong Grading type Volume of discharge (L/single stall) of AS 3982

Level 1 • Not more than 1.5 serving a single stall, and • conscious, demand-driven or smart-demand operation

Level 2 • Not more than 2.5 serving a single stall, and • conscious, demand-driven or smart-demand operation

Level 3 • Not more than 4.5 serving one stall, and • conscious, demand-driven or smart-demand operation

Level 4 • More than 4.5 serving a single stall

Not applicable Not applicable Not applicable AS/NZS 3982: a) Flushing test for slab and stall urinals b) Flushing test for single stall wall-hung urinals c) Splash test for urinals



3.3 Type of the Schemes

3.3.1 The schemes established in Australia, New Zealand and Singapore are of grading type. Under these schemes, all the urinals are rated to different grades of water efficiency in accordance with the volume of discharge test results and are subject to the compliance with other specified performance requirements. Labels will be affixed to the urinals so as to indicate their water consumption levels and efficiency grading.

3.3.2 The scheme established in U.S. is of recognition type. Verification water efficiency

labels would be fixed to those urinals that have met the specified volume of discharge requirement and are in compliance with the other specified performance criteria. Only one volume of discharge is specified in this type of scheme. It may not be flexible enough if different types of urinals have to be used under different situations.

3.3.3 In view of the higher flexibility, a grading system is recommended for the proposed technical standard for urinals in Hong Kong.

3.4 Types of Urinals

General

3.4.1 In this study, “urinals” means: (a) a urinal suite; (b) a urinal; (c) a urinal flushing control mechanism; or (d) a combination of a urinal and urinal flushing control mechanism

Wall Hung Urinals and Urinal Suite

3.4.2 The types of urinals specified in the schemes of Australia and New Zealand are similar as both schemes are implemented based on the same standard. Their standards are applicable to a wall hung urinal, connected to a cistern or a flush controller for flushing; a urinal suite, controlled by the flush controller installed in the suite. The flush volume of a urinal is mainly controlled by the cistern or the flushing valve. Other than the case of a urinal suite, the flushing valve and the urinal are separately installed. These types of urinals are covered in the standards of all 4 countries.

3.4.3 For water saving urinals (water-using urinals) defined by Australia and New Zealand, a urinal flushing control mechanism associated with these water saving urinals is mandatory. This is a device that controls the release of water to flush a urinal. Such devices can be classified by how they are operated, including: (a) Conscious operation

The flush is activated manually by the user (may be by pulling a cord or chain, or by pressing a button or foot pedal).

(b) Demand-driven operation The flush is activated automatically on demand, rather than by conscious activation of a user, with an adjustable activation sensitivity field at the front of the urinal or a urine-sensing device. Demand-driven operation does not



include a system that relies solely on a time clock or a fill-and-empty type mechanism.

(c) Smart-demand operation The flush is activated by programmable operation with an adjustable activation sensitivity field at the front of the urinal or a urine-sensing device to control a predetermined flush cycle, with smart logic that detects users, and controls programmable delay and flushing modes of the device. For example, in a smart-demand operation, the device might detect that people are queued up during interval at the theatre, and not initiate a flush after every user but rather after 5 users; or, if no flushing has been required for 30 min, the system might provide three flushes to clear the waste pipes and traps of urine and then shut down unit required; and, for long periods without user activity, the system might provide only one flush every 12 hours.

3.4.4 The standards of Singapore and US do not explicitly require the flushing control

mechanisms in the water saving urinals. Nevertheless, as flush water can be more efficiently used in the urinals if the flushing can be activated only on demand, it is recommended to implement the requirement of flushing control mechanism in the proposed Hong Kong standard. In fact, many urinals have already equipped with flush controllers operating under the modes of conscious or demand-driven operation in Hong Kong.

3.4.5 Some urinals are operated with a pre-flushing step to enhance hygienic condition. Although Singaporean standard does not allow pre-flush, flushing at fixed time intervals or multiple flushing features in any water saving urinal, there is no such requirement in other standards. Hence, the proposed Hong Kong standard for urinals will not prohibit any pre-flushing in the water saving urinals.

Waterless Urinals

3.4.6 This study does not apply to waterless urinals and trough urinals. Waterless urinals are not commonly used and their performance is yet to be assessed and proved. If necessary, an additional piece of technical standard specifying the applicable performance criteria and testing methodologies may be developed for the waterless urinals in the future.

3.4.7 From the aspect of water saving, a waterless urinal is definitely the best as it does

not require water for flushing. Nevertheless, routine cleaning procedures are necessary to be done. For example, daily cleaning of a waterless urinal may be necessary to be done. It may not be applicable if waterless urinals are installed in rural areas, such as country parks. In addition, some behaviors of users which may affect the performance of a waterless urinal are still necessary to be concerned, such as spitting to urinals.

Trough Urinals



3.4.8 Unlike wall-hung urinals, trough urinals are normally tailor-made in Hong Kong, which makes trough urinals difficult to satisfy the required performance criteria of the proposed technical standard of water efficiency urinals, like flushing test and splash test. However, there are no suitable factory-tested standard trough urinals available in Hong Kong market. In this regard, it is recommended not to include trough urinals in the proposed technical standard of water efficiency urinals for new buildings in Hong Kong.

3.5 Water Efficiency Grading

3.5.1 Since the proposed standard for urinals in Hong Kong is recommended to be of a grading type, its water efficiency grading will mainly make reference to the standards of Australia/New Zealand (The water efficiency grading of the standards of Australia and New Zealand are identical as they are based on the same standards, AS/NZS 6400:2005 – Water Efficient Products – Rating and Labeling.) and Singapore.

3.5.2 Figure 3.1 illustrates a general overview of the water efficiency grading in different

standards. It is recommended to adopt a similar water efficiency grading scale with the standards in overseas so that products in compliance with the oversea water efficiency standards can easily follow the Hong Kong’s proposed standard. As the Australian standard has been well established and explained in details. It is recommended to adopt the similar water efficiency grading scale in the standard of Hong Kong.

3.5.3 The volume of discharge of a urinal is controlled by the flushing cistern or flushing

apparatus, such as an electronic sensor flushing valve. In general, the volume of discharge of the flushing valves can be adjusted to any arbitrary value within the range allowed by the water pressure and the mechanical design of the valves. But the performance requirements of the urinals control the minimum volume of discharge required by the urinals.

3.5.4 In general, the volume of discharge of the water saving urinals available in Hong

Kong market is higher than that found in overseas because the minimum requirement of the volume of discharge for urinals in Hong Kong is specified to be 4.5 L as per WSD’s regulations. Therefore, it is proposed to relax the limit in order to encourage water conservation. Hence, “>4.5 L” is defined as Level 4, i.e. without any water saving. To simplify the grading system, 4 grades are proposed in the Hong Kong standard.

3.5.5 As shown in Figure 3.1, with reference to the oversea standards for urinals, the

water efficiency grading of the proposed Hong Kong standards will be defined as follows:

Level 4 - conventional urinals currently used (mostly flushed with cisterns) Level 3 - urinals with minimal water saving Level 2 - equivalent to 1-3 stars in the Australian/New Zealand standards Level 1 - the best flushing control mechanisms in the market (mostly flushing

with electronic sensor flushing valves), equivalent to 4-6 stars in the Australian/New Zealand standards

3.5.6 The proposed water efficiency grading of the Hong Kong standard for water saving

urinals is listed in Table 3.3. This water efficiency grading equivalent table is only



applicable to wall-hung single stall urinal because the definition of one equivalent stall for a trough urinal in Hong Kong is different from that in Australia/New Zealand.

Figure 3.1 Oversea Standards (Australia/New Zealand and Singapore) and

Recommended Hong Kong Standard for Urinals

Table 3.3 Water Efficiency Levels for Urinals

Proposed Hong Kong Standard Volume of Discharge f (L)



Level 3 (Good) 2.5 < f ≤ 4.5

Level 4 f > 4.5

Note: All water saving urinals in Hong Kong are proposed to have demand-driven flushing mechanism (such as electronic sensors) 3.6 Test Parameters

3.6.1 The WELS of Australia covers the most comprehensive test parameters and distribution of ranges in the water efficiency grading. However, not all the test parameters in the Australia/New Zealand standards are related to the water saving performance of the urinal. Volume of water discharge is the key measurement of the water saving urinals in all oversea standards and other parameters are the flushing test and splash test of the urinals. Therefore, the proposed standard for Hong Kong will only include the tests on the volume of discharge, flushing test and splash test, as shown in Table 3.4.

Table 3.4 Performance Requirements for Urinals



Performance Property Performance Requirements Flushing test for single stall wall-hung urinals


Splash test for urinals The urinals shall not splash water onto the floor. 3.7 Recommended Water Efficiency Grade

3.7.1 In the previous study for WSD’s water saving project, the recommended water efficiency grade of the water efficiency urinals was Level 2. It was due to the consideration about the difficulties to retrofit the existing urinals to achieve Level 1. However, there is no such constraint for new buildings.

3.7.2 With reference to the assessment criteria used in the previous study, the

recommended grade for new buildings is determined based on the following assessment criteria: - Water saving performance; - Technical applicability; and - Availability in local market The factor of cost implication is not considered in this study since the prices of the water efficiency urinals may vary substantially when they are getting popular in Hong Kong.


unless there are technical applicability problems or inadequate local availability hindering the use of Level 1 urinals.

3.7.4 The flushing performance of urinals is mainly dependent on two factors: the

flushing volume setting of the flushing apparatus and the design of urinal pans. The most common types of flushing apparatus in Hong Kong are flushing cisterns and flushing valves. In light of the type test results in the previous study, electronic sensor type flushing valves shall have no problem to meet the requirements of Level 1. As for the urinal pans, the type tests in the previous study have revealed that a number of urinal pans can be classified as Level 1. In this regard, there should be no technical applicability problems or inadequate local availability hindering the use of Level 1 urinals in Hong Kong.

3.7.5 As shown in the assessment result of Table 3.5, it is recommended to use wall-

hung type Level 1 (Excellent) urinals in the toilets of all new buildings except hospitals.

Table 3.5 Recommended Grade of Water Efficiency Urinals

Assessment Criteria Level 1 Level 2 Level 3 Water saving performance ��






3.8 Other Concerns for Urinals

3.8.1 Trough urinals are not recommended as water efficiency urinals for new buildings because of no suitable factory-tested standard products available in Hong Kong market. However, users shall be reminded that a trough urinal can normally occupy less space than the equivalent number of wall-hung urinals. Therefore, if it is intended to install water efficiency urinals in the new buildings, adequate space shall be allocated to accommodate enough number of wall-hung urinals.

3.8.2 If the urinal is used frequently, such as urinals of public toilets at downtown,

substantial amount of water is used for flushing due to frequent activation by the sensor. To achieve the best use of flushing water under such circumstance, one of the ways is to automatically reduce the volume of water discharge at each flush. This feature, occasionally named as reduced flush mode, is recommended to be embedded in urinals which are installed in public toilets with high volume usage.

3.8.3 It is advisable to install extra strainers before the flushing valves’ water filters so as

to prevent potential blockage of the water filters by solid particles such as silt and rust, in the flushing water.



4 Toilets/lavatory Equipment

4.1 Overview

4.1.1 Many types of water conservation appliances, such as household appliances and plumbing appurtenance, are available in the worldwide market. Different types of labelling schemes are implemented for different types of water conservation appliances around the world. For example, EU developed a “European Eco-label” scheme for dishwashers and washing machines.

4.1.2 Some countries recognize water saving toilets/lavatory equipment using “Eco-label” schemes. A summary of these schemes are listed in Table 4.1.

Table 4.1 Eco-label Schemes for Toilets/lavatory Equipment in Overseas

Location Name Performance Requirements Taiwan 省水標章 Full Flush:

f ≤ 6 L Reduced Flush: f ≤ 3 L

Japan Eco Mark Water-saving type water closet (low tank type): f ≤ 6.5 L

Canada Eco Label f ≤ 6 L

Korea KOECO Low tank type: f ≤ 9 L

4.1.3 In the mainland, the requirements of different water saving devices for plumbing



4.1.4 Water efficiency grading scheme of toilets/lavatory equipment have been implemented or being planned in overseas. Several schemes have been well established in Australia, New Zealand, Singapore, U.K. and U.S. Therefore, this review focuses on the standards established from these five countries. Details of the standards are listed in Table 4.2.

4.2 Natures of Schemes

4.2.1 The schemes established in Australia, New Zealand and Singapore are mandatory. And all the toilets/lavatory equipment specified under these schemes must be registered, rated and labeled according to the requirements of the standards. On the other hand, the schemes established in U.K. and U.S. are implemented on a voluntary basis. As an initiative to promote water saving in Hong Kong, the technical standard established in this project will be on a voluntary basis.



4.3 Type of Schemes

4.3.1 The schemes established in Australia, New Zealand and Singapore are of grading types. Under these schemes, all the toilets/lavatory equipment are rated to different grades of water efficiency in accordance with the volume of discharge test results and are subject to the compliance with other specified performance requirements. Labels will be affixed to the toilets/lavatory equipment so as to indicate their water consumption levels and efficiency grading.

4.3.2 The schemes established in U.K. and U.S. are of recognition types. Verification

water efficiency labels would be fixed to those toilets/lavatory equipment that have met the specified volume of discharge requirement and are in compliance with the other specified performance criteria. Only one value of “volume of discharge” is specified in this type of schemes. It may not be flexible enough if different types of toilets/lavatory equipment have to be used under different situations.

4.3.3 In view of the higher flexibility, a grading system is recommended for the proposed

technical standard for toilets/lavatory equipment in Hong Kong.



Table 4.2 Details of the Overseas Standards and Proposed Hong Kong Standard for Toilets/lavatory Equipment Water Efficiency Grading


Label Type Water Consumption Band 1 Band 2 Band 3 Band 4 Band 5 Band 6 Band 7 Test Parameters

Note


Grading type with "

" star

a) for single-flush cisterns - the discharge flush volume (L) of AS 1172.2 b) for dual-flush cisterns - the average of one full-flush discharge flush volume and four reduced-flush discharge volumes (L) of AS 1172.2 c) for a nominated combination of WC pan and single-flush flushing device - the discharge flush volue, determined from the operation of one full-flush cycle with the water collected and measured from the WC pan outlet d) for a nominated combination of WC pan and dual-flush flushing

Zero Star Not applicable (Must not exceed 5.5)

1 Star Full flush ≤ 9.5 Half flush ≤ 4.5 Average flush ≤ 5.5

2 Stars Full flush ≤ 9.5 Half flush ≤ 4.5 Average flush ≤ 4.5



5 Stars Full flush ≤ 4.7 Average flush ≤ 3.0

6 Stars Full flush ≤ 4.7 Average flush ≤ 2.5

AS 1172.1: a) Full-flush - paper discharge test b) Reduced-flush - paper discharge test c) Solids discharge test d) Leakage and capacity test e) Splash test f) Wetting test g) Reduced-flushed liquid containment test AS 1172.2: h) Distortion and leakage tests i) Eudurance test (outlet valve) j) Eudurance test (inlet valve) k) Discharge tests l) Flush pipe restrictor setting ATS 5200.021: m) Flushing performance n) Watertightness ATS 5200.020: o) Hydraulic strength test p) Endurance test

(1)

New Zealand

Mandatory (Under development)

Grading type with "

" star

a) for single-flush cisterns – the discharge flush volume (L) of AS 1172.2 b) for dual-flush cisterns – the average flush of one full-flush discharge (L) and four reduced-flush discharge volumes (L) of AS 1172.2

Zero Star Average flush ≥ 5.5

1 Star 4.5 < average flush ≤ 5.5

2 Stars 4.0 < average flush ≤ 4.5




6 Stars average flush ≤ 2.5

AS 1172.1: a) Volume of water used for each flush b) Various flushing performance tests that assess the ability to clear the bowl or surfaces AS 1172.2: c) Distortion and leakage tests

(1)


Volume of Discharge per Flush (L) (Dual Flush Low Capacity Flushing Cisterns - Full Flush & Reduced Flush)

Zero Tick Not applicable

Good (1 Tick) 4 < full flush ≤ 4.5 2.5 < reduced flush ≤ 3

Very Good (2 Ticks) 3.5 < full flush ≤ 4.0 2.5 < reduced flush ≤ 3

Excellent (3 Ticks) full flush ≤ 3.5 reduced flush ≤ 2.5

Not applicable

Not applicable

Not applicable

SS 378:1996 Volume of discharge per Flush

(2)



Water Efficiency Grading Country

Scheme Nature

Label Type Water Consumption Band 1 Band 2 Band 3 Band 4 Band 5 Band 6 Band 7 Test Parameters

Note

UK Voluntary Recognition type (with symbolic indication of flush volume)

Nominal volume of discharge (L) full flush ≤ 4.5 average in dual-flushing ≤ 4.5

Not applicable

Not applicable

Not applicable

Not applicable

Not applicable

Not applicable

WCs suites - Class 2 of EN 997 Depth of water seal Flush performance Water absorption Load testing Leak tightness Valve reliability Wash of the bowl Flushing of toilet paper Over-splashing After-flush volume Static load Durability Independent flushing cisterns - Pr EN 14055 Volume of discharge

US WaterSense Parnership programme by US EPA

Recognition type

Effective flush volume (gallon per flush) in accordance with ASME A112.19.2 and ASME A112.19.14

average water consumption ≤ 1.28 (4.8 L per flush)

Not applicable

Not applicable

Not applicable

Not applicable

Not applicable

Not applicable

ASME A112.19.2 and ASME A112.19.14 Flush Volume Waste Extraction Test

Hong Kong Grading type a) for single-flush cisterns - the discharge flush volume (L) of AS 1172.2 b) for dual-flush cisterns - the average of one full-flush discharge flush volume and four reduced-flush discharge volumes (L) of AS 1172.2 c) for a nominated combination of WC pan and single-flush flushing device - the discharge flush volume, determined from the operation of one full-flush cycle with the water collected and measured from the WC pan outlet d) for a nominated combination of WC pan and dual-flush flushing

Level 1 average flush ≤ 3.5

Level 2 3.5 < average flush ≤ 4.5

Level 3 4.5 < average flush ≤ 7.5

Level 4 average flush > 7.5

Not applicable

Not applicable

Not applicable

AS 1172.1: a) Full-flush - paper discharge test b) Reduced-flush - paper discharge test c) Solids discharge test d) Splash test e) Wetting test f) Reduced-flushed liquid containment test AS 1172.2: g) Discharge tests

Notes: (1) Where lavatory equipment has an integral basin or a basin directly connected to it, and the water from that basin is used to flush the toilet, the water consumption of the lavatory equipment is

taken to be 0.3 L less than would otherwise be the case

(2) To pass laboratory simulation test on waste transportation efficiency in pipes prescribed by PUB if full flush volume is less than 3.5 litres.



4.4 Types of Toilets/Lavatory Equipment

General

4.4.1 In Hong Kong, toilets/lavatory equipment are defined as: (a) a toilet suite; or (b) a water closet pan; or (c) a water closet cistern; or (d) a combination of a water closet and cistern

Toilet Suite/Water Closet and Flushing Cistern

4.4.2 The types of toilets/lavatory equipment specified in the schemes of Australia and New Zealand are similar as both schemes are implemented based on the same standards. All standards in overseas are applicable to these types of toilets.

4.4.3 A water closet flushing device, such as flushometer valve, is included in the standards of Australia and New Zealand. On the other hand, this water closet flushing device is excluded in the standards of Singapore, UK and US. There is a fundamental difference in the design of flushing a water closet using a flushometer and a water cistern. A different set of technical requirements is needed in the application of this water closet flushing device. Therefore, it is recommended that the water closet flushing device is excluded from the standard of water saving toilet/lavatory equipment for Hong Kong.

4.4.4 It is recommended that the standard of Hong Kong will applicable to all types of toilet suite, water closet and flushing cistern.

Squat Toilets

4.4.5 Unlike water closets which have dominated the market, squat toilets are seldom used in new buildings. In addition, squat toilets have very few choices in the market and little performance data are available. In general, squat toilets require more water for flushing than the water closets. In this regard, it is recommended not to include squat toilets in the proposed technical standard of water efficiency toilets/lavatory equipment for new buildings in Hong Kong.


4.5.1 Since the proposed standard for toilets/lavatory equipment in Hong Kong is

recommended to be a grading type, its water efficiency grading will mainly make reference to the standards of Australia/New Zealand (The water efficiency grading of the standards of Australia and New Zealand are identical as they are based on the same standards, AS/NZS 6400:2005 – Water Efficient Products – Rating and Labeling.) and Singapore.



4.5.2 Figure 4.1 illustrates a general overview of the water efficiency grading in different standards. It is recommended to adopt a similar water efficiency grading scale with the standards in overseas so that products in compliance with the oversea water efficiency standards easily follow the Hong Kong’s proposed standard. As the Australian standard has been well established and explained in details. It is recommended to adopt the similar water efficiency grading scale in the standard of Hong Kong.

4.5.3 In general, the volume of discharge of toilets/lavatory equipment is controlled by

the flushing cistern. But the performance requirements of the toilets/lavatory equipment control the minimum volume of discharge required by the toilets/lavatory equipment.

4.5.4 The water consumption of a cistern with dual flush is usually less than that of a

cistern with single flush. To facilitate comparison on a common ground, it is proposed to use the equivalent volume of discharge, which is defined as the average of one full-flush volume and four reduced-flush volume, for dual flush cisterns.

4.5.5 The volume of discharge of the toilets/lavatory equipment commonly used in Hong Kong is generally greater than those used in overseas because the minimum requirement of the volume of discharge for toilets/lavatory equipment in Hong Kong is specified to be 7.5 L as per previous WSD’s regulations. Hence, “>7.5 L” is defined as Level 4, equivalent to 0 Star in Australian/New Zealand standards, i.e. without any water saving. According to the database found at the webpage of Australian WELS, the toilets/lavatory equipment with 6 Stars is still not available in the markets. Therefore, only 4 grades are proposed in the Hong Kong standard so as to simplify the grading system.

4.5.6 The volume of discharge of the single flush cisterns in the local market is about 4.5 – 6 L. Therefore, single flush cisterns will be grouped as Level 3. The toilet/lavatory equipment equipped with 3 L / 6 L dual flush cisterns, i.e. 3 L for reduced flush and 6 L for full flush (equivalent volume of discharge approximately of 3.6 L), will be grouped under Level 2. The best water saving toilet/lavatory equipment is available in the Hong Kong market is the toilet/lavatory equipment equipped with 3 L / 4.5 L dual flush cisterns, i.e. 3 L for reduced flush and 4.5 L for full flush (equivalent volume of discharge approximately of 3.3 L), will be regarded as Level 1.

4.5.7 As shown in Table 4.2, with reference to the oversea standards for toilets/lavatory equipment, the water efficiency grading of the proposed Hong Kong standards will be rated as follows:

Level 4 - ordinary toilets with single flush cisterns currently used Level 3 - toilets equipped with better single flush cisterns Level 2 - toilets equipped with dual flush cisterns, equivalent to 2-3 stars in

the Australian/New Zealand standards Level 1 - toilets equipped with the best dual flush cisterns available in the

market, equivalent to 4-6 stars in the Australian/New Zealand standards

4.5.8 The proposed water efficiency grading of the Hong Kong standard for water saving

toilets/lavatory equipment is listed in Table 4.3.




Recommended Hong Kong Standard for Toilets/Lavatory Equipment

Table 4.3 Water Efficiency Levels for Toilets/Lavatory Equipment

Proposed Hong Kong Standard Equivalent Volume of Discharge

f (L)



Level 3 (Good) 4.5 < f ≤ 7.5

Level 4 f > 7.5

4.6 Test Parameters

4.6.1 The WELS of Australia covers the most comprehensive test parameters and distribution of ranges in the water efficiency grading. However, not all the test parameters in the Australian/New Zealand standards are related to the water saving performance of the toilets/lavatory equipment other than squat toilets. Volume of water discharge is the key measurement of the water saving toilets/lavatory equipment in all oversea standards.

4.6.2 Therefore, the proposed standard for Hong Kong will only include the tests on the

volume of discharge and the parameters listed in Table 4.4.



Table 4.4 Performance Requirements for Toilets/lavatory Equipment









4.7 Recommended Water Efficiency Grade

4.7.1 With reference to the assessment criteria used in the previous study, the recommended grade for new buildings is determined based on the following assessment criteria: - Water saving performance; - Technical applicability; and - Availability in local market The factor of cost implication is not considered in this study since the prices of the water efficiency toilets/lavatory equipment may vary substantially when they are getting popular in Hong Kong.

4.7.2 In the previous study for WSD’s water saving project, the recommended water

efficiency grade of the water efficiency toilets/lavatory equipment was Level 1. In general, Level 1 will be recommended from the perspective of water saving unless there are technical applicability problems or inadequate local availability hindering the use of Level 1 toilets/lavatory equipment.

4.7.3 The water efficiency technology for water closets (especially for wash down type)

is quite mature. All grades of water closets can be easily found in the market although Level 1 toilets/lavatory equipment may not be as common as the others.

4.7.4 As shown in the assessment result of Table 4.5, it is recommended to use Level 1

(Excellent) water efficiency toilets/lavatory equipment in the toilets of all new buildings except hospitals.



Table 4.5 Recommended Grade of Water Efficiency Toilets/Lavatory Equipment




Recommended grade Excellent Very Good Good 4.8 Other Concerns for Toilets/Lavatory Equipment

4.8.1 In general, there is little compatibility problem for the installation of water saving toilets/lavatory equipment to the existing plumbing system.

4.8.2 The flushing device water volume is reduced. So if the trap outlet of toilets/lavatory

equipment is not connected with the anti-syphonage pipe, the sewage cannot be drained away easily. This issue is expected to be prevented in new buildings as the trap outlets of toilets/lavatory equipment shall be connected to anti-syphonage pipe under the Building (Standards of Sanitary Fitments, Plumbing, Drainage Works and Latrines) Regulations [Hong Kong Law Chapter 123I].

4.8.3 The impurities in sea water may affect the performance of the flushing valve inside

the flushing cistern with sophisticated parts. We recommend the party concerned should contemplate the working capability of the flushing cistern with the impurities of sea water.

4.8.4 The habit of using dual flush toilets/lavatory equipments may be new to the users.

It may involve the habit of activating the reduced flush button or preventing to use excess amount of toilet paper. It is recommended to implement some publicity to educate the public on how to effectively use water saving toilets/lavatory equipments.



5 Showers

5.1 Overview

5.1.1 Many types of water conservation appliances, such as household appliances and plumbing appurtenance, are available in the worldwide market. Different types of labelling schemes are implemented for different types of water conservation appliances around the world. For example, EU developed an “European Eco-label” scheme for dishwashers and washing machines.

5.1.2 Some countries recognize water saving showers using “Eco-label” schemes. A summary of these schemes are listed in Table 5.1.

Table 5.1 Eco-label Schemes for Showers in Overseas

Location Name Performance Requirements Taiwan 省水標章 5 L/min ≤ f ≤ 10 L/min at 1 kg/cm2 with DN15

Canada Eco Label F ≤ 9.5 L/min at 5.5 kg/cm2

Korea KOECO F ≤ 9.5 L/min @ 98 kPa

5.1.3 In the mainland, the requirements of different water saving devices for plumbing



5.1.4 Water efficiency grading scheme of showers have been implemented or being planned in overseas. Several schemes have been well established in Australia, New Zealand, Singapore and U.K. Therefore, this review focuses on the standards established from these four countries. Details of the standards are listed in Table 5.2.

5.2 Nature of Schemes

5.2.1 The schemes established in Australia and New Zealand are mandatory and all the showers specified under these schemes must be registered, rated and labeled according to the requirements of the standards. On the other hand, the schemes established in Singapore and U.K. are implemented on a voluntary basis. As an initiative to promote water saving in Hong Kong, the technical standard established in this project will be on a voluntary basis.



Table 5.2 Overview of the Oversea Standards and Proposed Hong Kong Standard for Showers Water Efficiency Grading

Country Scheme Nature Label Type Water Consumption Band 1 Band 2 Band 3 Band 4 Band 5 Band 6 Band 7 Test Parameters

Australia Mandatory Grading type with "

" star






4 Stars 6 < flow rate ≤ 7.5 (when the force of spray test is finalized and incorporated into the standard)

5 Stars 4.5 < flow rate ≤ 6 (when the force of spray test is finalized and incorporated into the standard)

6 Stars 4.5 < flow rate ≤ 6 with additional bonus features (e.g. automatic shut-off) (when the force of spray test is finalized and incorporated into the standard)

AS/NZS 3662 a) Flowrate b) Mean spray angle c) Temperature drop d) Shower hoses e) Watertightness of end connections f) Flow controller

New Zealand Mandatory (Under development)

Grading type with "

" star





3 Stars 7.5 <flow rate ≤ 9

4 Stars 6 < flow rate ≤ 7.5 (when the force of spray test is finalized and incorporated into the standard)

5 Stars 4.5 < flow rate ≤ 6 (when the force of spray test is finalized and incorporated into the standard)

6 Stars 4.5 < flow rate ≤ 6 with additional features such as automatic shut-off (when the force of spray test is finalized and incorporated into the standard)

AS/NZS 3662 a) Flowrate b) Mean spray angle c) Temperature drop d) Flow controller endurance

Singapore Voluntary Grading type with " � " tick

Nominal flow rate (L/min) shall be the mean of the average flow rates obtained at the following dynamic flow pressures: 150 kPa, 250 kPa, 350 kPa, 450 kPa and 500 kPa, measured in accordance with AS/NZS 3662

Zero Tick Not applicable for voluntary scheme




Not applicable Not applicable Not applicable AS/NZS 3662 Flowrate

UK Voluntary Recognition type (with symbolic indication of flow rate)

Nominal flow rate (L/min), measurement method described in Guide to Test for the BMA WEPL Scheme

≤ 13 Not applicable Not applicable Not applicable Not applicable Not applicable Not applicable Guide to Test for the BMA WEPL Scheme Flowrate



Water Efficiency Grading Country Scheme Nature Label Type

Water Consumption Band 1 Band 2 Band 3 Band 4 Band 5 Band 6 Band 7 Test Parameters

Hong Kong Grading type



Level 2 9 < flow rate ≤ 12

Level 3 12 < flow rate ≤ 16

Level 4 flow rate >16.0

Not applicable Not applicable Not applicable AS/NZS 3662 a) Flowrate b) Mean spray angle c) Temperature drop d) Flow controller endurance



5.3 Types of Schemes

5.3.1 The schemes established in Australia, New Zealand and Singapore are of grading types. Under these schemes, all the showers are rated to the different grades of water efficiency in accordance with the flow rate test results and are subject to the compliance with other specified performance requirements. Labels will be affixed to the showers so as to indicate their water consumption levels and efficiency grading.

5.3.2 The schemes established in U.K. are of recognition type. Verification water efficiency labels would be fixed to those showers that have met the specified water flow rate requirement and are in compliance with the other specified performance. Only one flow rate is specified in this type of schemes. It may not be flexible enough if different types of showers have to be used under different situations.

5.3.3 In view of the higher flexibility, a grading system is recommended for the proposed technical standard for showers in Hong Kong.

5.4 Types of Showers

5.4.1 A shower may include the showerhead and the accessories such as fixed or pivot arm, a flexible hose (with or without a flow controller), tap top assemblies or other components, which is used solely for personal bathing. There are different types of showers available in the markets, such as: (a) wall mounted shower and (b) hand shower

5.4.2 The types of showers specified in the schemes of Australia and New Zealand are

similar as both schemes are implemented based on the same standard. Their standards are applicable to all types of showers. The tests include the showerhead and the accessories such as fixed or pivot arm, a flexible hose (with or without a flow controller), tap top assemblies or other components. The water efficiency is rated in accordance with the nominal flow rate of the showerhead. Similar types of showers are covered by the scheme implemented in Singapore.

5.4.3 On the other hand, the standard of U.K. is applicable to the shower control, such as mixing valve, mixer, hose and outlet. It includes more items than that in Australian/New Zealand standards. Some items, such as the mixing valve and mixer have been covered by the standards for other water saving devices in Australia/New Zealand.

5.4.4 Therefore, it is recommended to cover the showerhead only in the standard for showers in Hong Kong.


5.5.1 Since the proposed standard for showers in Hong Kong is recommended to be a grading type, its water efficiency grading will mainly make reference to the standards of Australia/New Zealand (The water efficiency grading of the standards of Australia and New Zealand are identical as they are based on the same standards, AS/NZS 6400:2005 – Water Efficient Products – Rating and Labeling) and Singapore.



5.5.2 Figure 5.1 illustrates a general overview of the water efficiency grading in different standards. It is recommended to adopt a similar water efficiency grading scale with the standards in overseas so that products in compliance with the oversea water efficiency standards can easily follow the Hong Kong’s proposed standard. As the Australian standard has been well established and explained in details. It is recommended to adopt the similar water efficiency grading scale in the standard of Hong Kong.

5.5.3 In general, the best water saving showers is defined as the showers with a

maximum flow rate no more than 4.5 L/min according to the standards in Australia/New Zealand. However, the products labelled as 4-6 Stars in Australia are not commonly available in Hong Kong. To simplify the grading system, only 4 grades are proposed in the Hong Kong standard instead of 7 grades in the Australia/New Zealand standards (i.e. 3 - 6 Stars are all grouped as Level 1) because these groups of showers can be regarded as highest grade of water saving showers.

5.5.4 As shown in Table 5.3, with reference to the oversea standards for showers, the

water efficiency grading of the proposed Hong Kong standards will be rated as follows:

Level 4 - ordinary showers currently used Level 3 - showers equivalent to 1 star in the Australian/New Zealand

standards Level 2 - showers equivalent to 2 stars in the Australian/New Zealand

standards Level 1 - The best water efficient showers equivalent to 3-6 stars in the

Australian/New Zealand standards

Table 5.3 Water Efficiency Levels for Showers

Hong Kong Standard Nominal Flow Rate

f (L/min)



Level 3 (Good) 12.0 < f ≤ 16.0

Level 4 f > 16.0




Recommended Hong Kong Standard for Showers

5.6 Test Parameters

5.6.1 The WELS of Australia covers the most comprehensive test parameters and distribution of ranges in the water efficiency grading. However, not all the test parameters in the Australia/New Zealand standards are related to the water saving performance of the showers. Flow rate is the key measurement of the water saving showers in all oversea standards and another parameter are the mean spray angle, the temperature drop and the flow controller. Therefore, the proposed standard for Hong Kong will only include the tests on the nominal flow rate and the mean spray angle, the temperature drop and the flow controller, as shown in Table 5.4.

Table 5.4 Performance Requirements for Showers




Mean spray spread angle The mean spray spread angle shall be between 0° and 8°.

Temperature drop The temperature drop shall not exceed 3 °C. Endurance of the flow controller (if incorporated in a shower or being a component of a shower)

The flow rate shall be within ±1 litre/min of the nominal flow rate, as determined in the flow rate test.




5.7.1 With reference to the assessment criteria used in the previous study, the recommended grade for new buildings is determined based on the following assessment criteria: - Water saving performance; - Technical applicability; and - Availability in local market The factor of cost implication is not considered in this study since the prices of the water efficiency showers may vary substantially when they are getting popular in Hong Kong.


unless there are technical applicability problems or inadequate local availability hindering the use of Level 1 showers.

5.7.3 Technically, the water saving technology for showers is actually quite mature in

overseas although water efficiency showers are not commonly used in Hong Kong. Most of the water efficiency showers achieve flow reduction by means of flow restrictors.

5.7.4 Nevertheless, similar to the mixer taps, showers are normally associated with

some water heating systems to provide hot water supply. There may be compatibility issues when water efficiency showers are connected to the domestic water heaters as every instantaneous type domestic heater requires a minimum flow in order to trigger its operation. If the flow rates of the water efficiency showers are too small, especially when the water supply pressure is relatively low, the water heaters may not operate.

5.7.5 To resolve this compatibility problem, it is recommended:

(a) To maintain a water supply pressure of at least 150kPa at the cold water inlet of the individual water heater in all new buildings;

(b) To limit the variation of the actual flow rates for each water efficiency shower under pressures between 150 kPa and 350 kPa to within ±1 L/min of the nominal flow rate as determined in the flow rate test; and


5.7.6 For the highest floors of a building, fresh water is normally supplied from the

rooftop fresh water tank by gravity without any booster pump. The water supply pressure can be less than 150kPa. In order to make sure that the actual flow rates of the water efficiency showers would not be far below their specified nominal flow rates, causing operational problem to the domestic water heaters, it is recommended to explicitly specify a minimum water supply pressure of at least 150 kPa to be maintained at the cold water inlet of the individual water heater in all new buildings.

5.7.7 Currently, there is no restriction for the maximum difference between the highest

and lowest average flow rates of the showers in Hong Kong. Again, to avoid great deviation of the actual flow rates of the water efficiency showers from their specified nominal flow rates, it is deemed necessary to limit the variation of the actual flow rates for each water efficiency shower under pressures between 150



kPa and 350 kPa to within ±1 L/min of the nominal flow rate, as stated in the performance requirements in Table 5.4.

5.7.8 According to the compatibility test, the flow-controlled water heaters, no matter if

town gas, LPG or electricity is used, have minimum flow rate requirement of about 3 L/min. Whereas, the pressure-controlled water heaters, again no matter if town gas, LPG or electricity is used, normally require higher minimum water flow rates than the flow-controlled ones to trigger the operations. Their values vary from 3 L/min to about 5.8 L/min. In the case of storage type water heaters, no minimum flow rate is required for their operation. Therefore, if the variation of the actual flow rates for each water efficiency shower under pressures between 150 kPa and 350 kPa is restricted to within ±1 L/min of its nominal flow rate, the nominal flow rate needs to be above 6.8 L/min in theory in order to activate the domestic water heater’s operation. Hence, the proposed Level 1 water efficiency showers with nominal flow rates of <9 L/min shall basically be compatible to most domestic water heaters if recommendations in Paragraph 5.7.5 can be done.

5.7.9 All grades of water efficiency showers are available in the market although Level 1

showers may not be as common as the others. 5.7.10 As shown in the assessment result of Table 5.5, it is recommended to use Level 1

(Excellent) water efficiency showers in the toilets of all new buildings except hospitals.

Table 5.5 Recommended Grade of Water Efficiency Showers




Recommended grade Excellent Very Good Good 5.8 Other Concerns

5.8.1 The water supply pressure at the cold water inlet of the individual water heater is proposed to be maintained at no less than 150 kPa.

5.8.2 The variation of the actual flow rates for each water efficiency shower under

pressures between 150 kPa and 350 kPa is proposed to limit to within ±1 L/min of the nominal flow rate as determined in the flow rate test.

5.8.3 Users shall be reminded that although most of the water efficiency showers shall

have no problem to trigger the operation of the domestic water heater (except electric pressure controlled type water heater), the flexibility for the showers to control the final water temperature is, to some extent, reduced. It is because less amount of cold water can be mixed with the hot water by a water efficiency shower to produce a desirable water temperature. The designers of the buildings should contemplate the issue of flexibility in temperature adjustment and the minimum flow rate requirement to trigger the water heater.

5.8.4 In general, all grades of water efficient showers are applicable to flow controlled

type water heaters.



5.8.5 In case of pressure controlled type water heater (except electric pressure controlled type water heater) which has relatively high minimum flow rate requirement, limitation of water flow by water efficient showers hamper the flexibility in water temperature adjustment by deducting the amount of cold water available for mixing with hot water derived from water heater. As regards this issue, only water efficient showers with water flow rate no less than 7 L/min under inlet pressure of 150kPa at shower head are suggested to be used in conjunction with pressure controlled type water heaters and no water efficient showers are recommended for electric water heaters which have relatively fairly high minimum flow rate requirement..

5.8.6 In case of storage type electric water heater which has no minimum flow rate

requirement, all grades of water efficient showers with generally no hampering of flexibility in water temperature adjustment are recommended.



Part 3 – Technical Standards and Specifications



6 Proposed Technical Standard for Taps

6.1 Scope

6.1.1 This proposed standard specifies the water efficiency grading and performance requirements together with test methods for taps.

6.1.2 In this study, “taps” means any tap or tap outlet that is for use over a basin and kitchen sink, regardless of the operating mechanism. Note: Tap types include combination taps, mixing taps, electronic taps/sensor taps.

6.1.3 This standard does not apply to any tap or tap outlet that is: (a) solely for use over a bath; or (b) part of an appliance such as a chilled or boiling water dispenser.

6.2 Water Efficiency Grading for Non-mixer Taps

6.2.1 The water efficiencies of the non-mixer taps are rated to different grades according to their nominal flow rates as shown in Table 6.1. Level 1 is the most water efficient (Excellent) whereas Level 3 is the least water efficient (Good). Level 4 is not classified as a water efficient non-mixer tap.

Table 6.1 Conversion of Nominal Flow Rates to Water Efficiency Grades

of Non-mixer Taps Nominal Water Flow Rate

f (L/min) Water Efficiency Grade

f ≤ 2.0 Level 1 (Excellent) 2.0 < f ≤ 4.0 Level 2 (Very Good) 4.0 < f ≤ 6.0 Level 3 (Good)

f > 6.0 Level 4 6.2.2 An extra merit is proposed to the non-mixer taps with automatic shut-off

mechanism. 6.2.3 If the tested non-mixer tap cannot fulfill the performance requirements specified in

Section 6.4. The non-mixer taps will be classified as Level 4. 6.3 Water Efficiency Grading for Mixer Taps

6.3.1 The water efficiencies of the mixer taps are rated to different grades according to their nominal flow rates as shown in Table 6.2. Level 1 is the most water efficient (Excellent) whereas Level 3 is the least water efficient (Good). Level 4 is not classified as a water efficient non-mixer tap.



Table 6.2 Conversion of Nominal Flow Rates to Water Efficiency Grades of Mixer Taps

Nominal Water Flow Rate f (L/min)

Water Efficiency Grade


f > 9.0 Level 4 6.3.2 An extra merit is proposed to the mixer taps that can achieve a nominal flow rate

≤2 L/min, while another extra merit is proposed to the mixer taps with automatic shut-off mechanism.

6.3.3 If the tested mixer tap cannot fulfill the performance requirements specified in

Section 6.4. The mixer taps will be classified as Level 4. 6.4 Test Parameters and Methodology

6.4.1 The nominal flow rates of the both non-mixer and mixer taps shall be tested in accordance with the testing methodology specified in AS/NZS 3718:2005. The taps are then rated to different grades according to the nominal flow rate test results subject to the compliance with other performance requirements as shown in Table 6.3.

Table 6.3 Performance Requirement for Non-mixer and Mixer Taps Performance Property Performance Requirements




6.4.2 The taps shall be designed and manufactured under a design and production

system operating according to a recognized international quality system (such as ISO 9001).

6.5 Testing Laboratories and Accreditation Bodies

6.5.1 The testing is to be carried out either by an independent testing laboratory or by the manufacturers or the importers or other related parties themselves at their own testing laboratories. The results and certificates issued by the testing laboratories which fulfil one of the criteria as specified in paragraphs 6.5.2, 6.5.3 or 6.5.4 will be accepted.

HOKLAS laboratories

6.5.2 The laboratory is accredited by the Hong Kong Accreditation Service (HKAS) for carrying out the tests stipulated in this Scheme under the Hong Kong Laboratory Accreditation Scheme (HOKLAS) or a scheme with which the HKAS has



concluded a mutual recognition agreement; and the results are issued in a test report or certificate bearing the accreditation mark.

In-house laboratories

6.5.3 An in-house laboratory fulfilling the criteria listed below:- (a) Self-declaration by the manufacturer or importer or other related parties that

the operations of their in-house laboratory follow the requirements of ISO/IEC 17025; and

(b) The manufacturer is currently operating according to a recognized international quality system (such as ISO 9001); and

(c) The manufacturer’s or importer’s or other related parties’ in-house laboratory has been successful in carrying out tests on taps and where these tests have been evaluated and certified by internationally recognised third party certification organisations.

Other laboratories

6.5.4 A laboratory which achieves HOKLAS accreditation (or is accredited by a scheme with which HKAS has concluded a mutual recognition agreement) for laboratory testing of plumbing fixtures and water-consuming appliances other than the tests stipulated in the Scheme, and the laboratory can demonstrate capability of carrying out tests on taps in accordance with AS/NZS 3718:2005.



7 Proposed Technical Specification of Taps

7.1 Recommended Water Efficiency Grade for Non-Mixer Taps

7.1.1 It is recommended to use Level 1 (Excellent) water efficiency non-mixer taps in the toilets of all new buildings except hospitals.

7.1.2 Users may consider lower levels of water efficiency taps if they have concerns

about hygiene in some critical applications, like clinics or elderly centres. 7.1.3 Users shall also be reminded that as the flow rates of the water efficiency taps will


7.1.4 Users shall also consider using non-mixer taps with automatic shut-off mechanism

and an extra credit will be given to recognize the additional benefit in water saving. 7.1.5 The recommended grades of water efficiency of non-mixer taps for different

applications are summarized in Table 7.1.



Table 7.1 Recommended Grades of Non-mixer Taps for Various Applications

Level 1# Excellent

(f ≤ 2.0 L/min)

Level 2# Very Good

(2.0 L/min < f ≤ 4.0 L/min)

Level 3# Good

(4.0 L/min < f ≤ 6.0 L/min)

- No technical constraints; - Used in public places ; - For general personal hygiene purpose - Mainly for hand washing; - Not recommended for high volume

usage such as cleansing and filling up containers like kettles and buckets,


- No technical constraints; - Used in private and public facilities; - For general personal hygiene purposet; - For high volume usage such as


- For facilities that involve physical activities such as sports which lead to frequent and high volume usage.


- Examples: Toilets for residential premises, including dormitories of boarding schools and universities, performance venues (e.g. town halls, cultural centres, theatres etc.), schools and leisure venues (e.g. sports centres, playgrounds, sports stadiums, swimming pools etc,


hygienic condition. - For higher personal hygiene


cleansing of dirty substances to remove germs.





7.2 Recommended Water Efficiency Grade for Mixer Taps

7.2.1 Level 1 is recommended from the perspective of water saving unless there are technical applicability problems or inadequate local availability hindering the use of Level 1 mixer taps.

7.2.2 Level 1 water efficiency mixer taps will be recommended if storage type water

heaters or centralized water heating systems can be used in the new buildings. Whereas, if instantaneous type water heaters have to be used, it is recommended to use flow-controlled type water heaters and Level 2 water efficiency mixer taps will be compatible to these water heaters. However, if only pressure-controlled type instantaneous water heaters can be used, it will be advisable to install Level 3 water efficiency mixer taps in order to avoid any compatibility problem between the taps and the water heaters.

7.2.3 Similar to non-mixer taps, users may consider lower levels of water efficiency taps

if they have concerns about hygiene in some critical applications, like clinics or elderly centres.



7.2.5 When storage type water heaters or centralized water heating systems are used,

users may consider using mixer taps with nominal flow rates of < 2 L/min so as to get an extra credit.

7.2.6 Users shall also consider using mixer taps with automatic shut-off mechanism and

an extra credit will be given to recognize the additional benefit in water saving. 7.2.7 The recommended grades of water efficiency of non-mixer taps for different

application are summarized in Table 7.2.



Table 7.2 Recommended Grades of Mixer Taps for Various Applications Level 1*, # Excellent

(f ≤ 5.0 L/min)

Level 2# Very Good

(5.0 L/min < f ≤ 7.0 L/min)

Level 3# Good

(7.0 L/min < f ≤ 9.0 L/min)






















7.3 Technical Specifications of Non-mixer and Mixer Taps on Materials

Compatibility to existing system

7.3.1 An issue is related to the compliance of water saving taps to certain British Standards in order to obtain the approval from Office of the Water Authority. Water saving taps may not comply with certain condition stated in the British Standard, such as the flow rate requirement in BS 1415:Part 2:1986.

7.3.2 As informed by the Water Supplies Department, the flow rate requirement in BS

1415:Part 2:1986 has been relaxed. It is no longer necessary to comply with this flow rate requirement in order to obtain the approval from Office of the Water Authority.

General Specification for Building (2007 Edition)

7.3.3 This section of technical specification makes reference to the section of “Sanitary Appliances” of General Specification for Building (2007 Edition) issued by the Architectural Services Department.

7.3.4 Taps and combination tap assemblies shall be chromium plated brass to BS 5412.

7.3.5 Taps shall be:

(a) Sensor tap shall conform to BS EN 816:1996. Operating pressure between 0.3-10 bar. Flow rate 2-6 litre per min. Max. water temp. 80 degree aerator. Self cleaning. Turn-off control pre-set 0-3 sec.

(b) Sensor mixer or cold. (c) Self-closing tap for time delay function.

Specification Library 2008 Edition

7.3.6 This section of technical specification makes reference to the section of “Sanitary Appliances” of Specification Library 2008 Edition issued by the Hong Kong Housing Authority.

7.3.7 The bath/showers mixers and basin mixers shall be tested for conformity with the

performance requirements as shown in Table 7.3.



Table 7.3 Performance Requirement for Bath/showers Mixers and Basin Mixers

Reference to the Specification Library 2008 Edition Items Method Acceptance Standards Flow Rate BS 1415:Part 1:1976:

Cl. 12.1 BS 1415:Part1:1976: Cl.12.3

Water Tightness Tests BS 5412:1996: Cl.8.2.1 to 8.2.3

BS 5412:1996: Cl.8.2 & Table 12

Pressure Resistance Tests BS 5412:1996:Cl.9.2 BS 5412:1996: Cl.9.2.2.2 and 9.2.3.2

Mechanical Strength Test BS 5412:1996:Cl.11 BS 5412:1996:Cl.11.2.4 Mechanical Endurance Tests

- Endurance Test of the Operating Mechanism

BS 5412:1996:Cl.12.1 BS 5412:1996:Cl.12.1.4

- Endurance of Diverters (For bath mixer only)

BS 5412:1996:Cl.12.2 BS 5412:1996:Cl.12.2.2

Pressure Drop Test (For bath mixer & shower mixer only)

Method No.1 Total pressure drop across the mixer with hot water tap fully open and cold water tap fully closed not more than 0.25 bar at 7 litre/minute

Blend Water Extreme Temperature

BS 5779:1979:Cl.16 & App K Temperature of supply water: Cold water = 20°C ± 1°C Hot water = 82°C ± 1°C

BS 5779:1979:Cl.16

7.3.8 The performance requirements indicated in red and bold in Table 7.3 are

recommended to be relaxed. The requirement on flow rate is not related to the other essential performance requirements of water saving taps, such as water tightness, pressure resistance and mechanical endurance. The requirement on pressure drop is indispensable only at locations with low water pressure. The number of these locations is expected to be minimal in new buildings, as the water pressure is proposed to be maintained at no less than 150 kPa. Therefore, these two requirements are recommended to be relaxed.

7.3.9 The kitchen sink mixers shall be tested for conformity with the performance

requirements as shown in Table 7.4.



Table 7.4 Performance Requirement for Kitchen Sink Mixers Reference to the

Specification Library 2008 Edition Items Method Acceptance Standards Flow Rate BS 1415:Part 1:1976:

Cl. 12.3 BS 1415:Part1:1976: Cl.12.3

Water Tightness Tests BS 5412:1996: Cl.8.2 (Tests in Cl.8.2.4 & 8.2.5 do not apply)

BS 5412:1996:Cl.8.2 & Table 12

Pressure Resistance Tests BS 5412:1996:Cl.9.2 BS 5412:1996:Cl.9.2.2.2 and 9.2.3.2

Mechanical Strength Test BS 5412:1996:Cl.11 BS 5412:1996:Cl.11.2.4 Mechanical Endurance Tests

- Endurance Test of the Operating Mechanism

BS 5412:1996:Cl.12.1 BS 5412:1996:Cl.12.1.4

- Endurance of Swivel Nozzles

BS 5412:1996:Cl.12.3 BS 5412:1996:Cl.12.3.2.4

Blend Water Extreme Temperature

BS 5779:1979:Cl.16 & App K Temperature of supply water: Cold water = 20°C ± 1°C Hot water = 82°C ± 1°C

BS 5779:1979:Cl.16

7.3.10 The performance requirements indicated in red and bold in Table 7.4 is

recommended to be relaxed. The requirement on flow rate is not related to the other essential performance requirements of water saving taps, such as water tightness, pressure resistance, mechanical strength and mechanical endurance. Therefore, this requirement is recommended to be relaxed.

Specification developed from the proposed standard

7.3.11 The water supply pressure at the cold water inlet of the individual water heater is maintained at no less than 150 kPa for mixer taps.

7.3.12 From the environmental perspective, taps equipped with energy saving features,

such as solar panels to drive the electronic sensors, shall be encouraged to use. 7.3.13 In respect of the taps with automatic shut-off devices, the time for the tap to be

closed should be as short as possible in order to minimize the water wastage. Taps with maximum closing time of no more than 1 min are recommended.

7.3.14 The taps shall be tested for conformity with the performance requirements as

shown in Table 7.5.

Table 7.5 Performance Requirement for Non-mixer and Mixer Taps Performance Property Performance Requirements



Endurance of the flow controller The flow rate shall be within ±1 litre/min of the nominal flow rate, as determined in the flow rate test.



7.3.15 The testing methodology is with reference to the testing conditions and

requirements specified in the Australia/New Zealand Standard No. AS/NZS 3718:2005 – Water Supply – Tap Ware with Amendment Nos. 1 and 2. The non-mixer and mixer taps are then rated to different grades according to Table 6.1 and Table 6.2 respectively.

7.4 Technical Specification of Non-mixer and Mixer Taps on Workmanship


7.4.1 This section of technical specification makes reference to the section of “Sanitary Appliances” of General Specification for Building (2007 Edition) issued by the Architectural Services Department.

7.4.2 Fix taps to make water tight seal with the sanitary appliance. Place hot tap to left of

cold tap as viewed by the user. Ensure that Hot/Cold markings are correctly applied and located.



8 Proposed Technical Standard for Urinals

8.1 Scope

8.1.1 This proposed standard specifies the water efficiency grading and performance requirements together with test methods for urinals.

8.1.2 In this proposed standard, “urinals” means:

(a) a urinal suite; (b) a urinal; (c) a urinal flushing control mechanism; or (d) a combination of a urinal and urinal flushing control mechanism

8.1.3 This standard does not apply to waterless and trough urinals. 8.2 Water Efficiency Grading

8.2.1 The water efficiencies of the urinals are rated to different grades according to their volume of discharge as shown in Table 8.1. Level 1 is the most water efficient whereas Level 3 is the least water efficient (Good). Level 4 is not classified as a water efficient urinal.

Table 8.1 Conversion of Volume of Discharge to Water Efficiency Grades

Volume of Discharge f (litre)

Water Efficiency Grade


f > 4.5 Level 4 8.2.2 A urinal flushing control mechanism associated with these water saving urinals is

necessary. This is a device that controls the release of water to flush a urinal. Such devices can be classified by how they are operated, as follows: (a) Conscious operation

The flush is activated manually by the user (may be by pulling a cord or chain, or by pressing a button or foot pedal).

(b) Demand-driven operation The flush is activated automatically on demand, rather than by conscious activation of a user, with an adjustable activation sensitivity field at the front of the urinal or a urine-sensing device. Demand-driven operation does not include a system that relies solely on a time clock or a fill-and-empty type mechanism.

(c) Smart-demand operation The flush is activated by programmable operation with an adjustable activation sensitivity field at the front of the urinal or a urine-sensing device to control a predetermined flush cycle, with smart logic that detects users, and controls programmable delay and flushing modes of the device. For example, in a smart-demand operation, the device might detect that people are queued up during interval at the theatre, and not initiate a flush after every user but rather after 5 users; or, if no flushing has been required for 30 min, the system might provide three flushes to clear the waste pipes and



traps of urine and then shut down unit required; and, for long periods without user activity, the system might provide only one flush every 12 hours.

8.2.3 If the tested urinals cannot fulfill the performance requirements specified in Section

8.3. The urinals will be classified as Level 4. 8.3 Test Parameters and Methodology

8.3.1 The volume of discharge of the urinals shall be tested in accordance with the testing methodology specified in AS/NZS 3982:1996. The urinals are then rated to different grades according to the volume of discharge test results subject to the compliance with other performance requirements as shown in Table 8.2.

Table 8.2 Performance Requirements for Urinals


Flushing test for single stall wall-hung urinals


Splash test for urinals The urinals shall not splash water onto the floor. 8.3.2 The urinals shall be designed and manufactured under a design and production



8.4.1 The testing is to be carried out either by an independent testing laboratory or by the manufacturers or the importers or other related parties themselves at their own testing laboratories. The results and certificates issued by the testing laboratories which fulfils one of the criteria as specified in paragraphs 8.4.2, 8.4.3 or 8.4.4 will be accepted.

HOKLAS Laboratories

8.4.2 The laboratory is accredited by the Hong Kong Accreditation Service (HKAS) for carrying out the tests stipulated in this Scheme under the Hong Kong Laboratory Accreditation Scheme (HOKLAS) or a scheme with which the HKAS has concluded a mutual recognition agreement; and the results are issued in a test report or certificate bearing the accreditation mark.





(c) The manufacturer’s or importer’s or other related parties’ in-house laboratory has been successful in carrying out tests on urinals and where these tests



have been evaluated and certified by internationally recognised third party certification organisations.

Other laboratories

8.4.4 A laboratory which achieves HOKLAS accreditation (or is accredited by a scheme with which HKAS has concluded a mutual recognition agreement) for laboratory testing of plumbing fixtures and water-consuming appliances other than the tests stipulated in the Scheme, and the laboratory can demonstrate capability of carrying out tests on urinals in accordance with AS/NZS 3982:1996.



9 Proposed Technical Specification of Urinals


9.1.1 It is recommended to use wall-hung type Level 1 (Excellent) urinals in the toilets of all new buildings except hospitals.

9.1.2 If it is intended to install water efficiency urinals in the new buildings, adequate

space shall be allocated to accommodate enough number of wall-hung urinals. 9.2 Technical Specification on Materials

Hong Kong Waterworks Standard Requirements for Plumbing Installation in

Buildings

9.2.1 According to Hong Kong Waterworks Standard Requirements for Plumbing Installation in Buildings Feb 2004 Version, issued by Water Supplies Department (WSD), the water discharge mechanism of flushing devices shall either be one of the following types: (a) with a flushing cistern:

(i) valveless siphonic; (ii) drop valve; (iii) flap valve; or (iv) dual flush valve;

(b) without a flushing cistern: (i) flushing valve (flushometer valve).

They can either be actuated by mechanical means or by sensors. 9.2.2 Every flushing cistern shall have an overflow terminating in a conspicuous position.

9.2.3 The discharge volume of the flushing devices shall be preset at the smallest compatible with the toilet bowl to ensure that effective clearance can be achieved by a single flush of water.

9.2.4 The requirements on the use of valve type flushing cisterns (refer to paragraph

9.2.1(a)(ii), (iii) and (iv)) are as follows: (a) The valve seal of the flushing devices shall be easily replaceable. (b) A dual flush valve which is designed to give two different volumes of flush

shall have a readily discernible method of actuating the flush at different volumes. Such method should be illustrated clearly and permanently displayed at the cistern or nearby.

(c) For dual flush devices, the reduced flushing volume shall not be more than two-thirds of the larger flushing volume.

(d) The components of all valve type flushing devices shall be resistant to salt water corrosion.

(e) The flushing devices must pass the 200,000-cycle endurance test. 9.2.5 The requirements on the use of flushing valves (refer to paragraph 9.2.1(b)) are as

follows: (a) Installation of a filter before a flushing valve or a group of flushing valves is

required.



(b) The cartridge and other valve components shall be easily replaceable. (c) The valve components shall be resistant to salt water corrosion. (d) Flushing valves shall be used within the range of working pressures specified

by the manufacturer. (e) The flushing devices must pass the 200,000-cycle endurance test. (f) Flushing valve shall only be used where there is a good maintenance

management system for frequent inspection and cleaning of filters. Normally only public toilets (such as those administered by government, quasi-government bodies, hotel operators, commercial complex management offices, etc.) will be considered.

(g) To facilitate users to report defective flushing valves in case they occur, it is advisable to secure in a conspicuous place in the public toilet, where the flushing valves are installed, a plate etched with the name of the responsible party and the telephone number in both Chinese and English. Other effective arrangements may also be considered.

9.2.6 For an existing building with permission to use mains water (fresh or salt) for

flushing purposes, any existing flushing apparatus found unsuitable shall be replaced with a proper apparatus as specified above.

9.2.7 It is the requirement under the Buildings Ordinance [Hong Kong Law Chapter 123]

that all new buildings shall be provided with a plumbing system to supply water for flushing purposes and every part of such plumbing system (including the storage tank) shall be constructed of such materials that are suitable for use with salt water.


9.2.8 This sections of technical specification makes reference to the section of “Sanitary Appliances” of General Specification for Building (2007 Edition) issued by the Architectural Services Department.

Flushing valve

9.2.9 In the case of urinals, the discharge volume shall be not less than 4.5 litres for every basin or stall, or for every metre of a trough urinal. The flow rate of the flush water shall be adjustable. The flush valve to maintain a minimum of 1.5 litres/second flow rate.

Urinals

9.2.10 Sensor valve shall conform to BS EN 12164’sCW602N. Operating pressure shall be 0.3-10 bar rinse. Time-off control approx. 9 sec. and remote adjust from 7-22 sec. Dry battery shall be 6V Lithium 2 CR5. A/C operate shall be 220-230/50z; voltage 6V. Sensor fittings shall be suitable for use in salt water application.

9.2.11 The performance requirements indicated in red and bold above is recommended to be relaxed. The relax on the discharge volume will not affect the performance of urinals as they are specified by the technical specification developed from the proposed standard.





9.2.13 The urinals shall be tested for conformity with the performance requirements as

shown in Table 9.1.

Table 9.1 Performance Requirement for Urinals Reference to the Specification Library 2008 Edition

Items Requirements Bowl Urinal Suite Comprising

1. Vitreous china bowl to BS 5520:1977: (a) Inlet supply: top of surface fixed pipework or back

for concealed pipeworks; (b) Non-corroding, concealed, screw fixed brackets; (c) Colour: as shown on Drawings or to Approval.

2. Plastics waste outlet, 40 mm nominal size with backnut and plastics or stainless steel domed outlet grating


9.2.14 A reduced flush mode can be automatically activated when urinals are used frequently in public toilets w ith high volume usage.

9.2.15 The urinals shall be tested for conformity with the performance requirements as

shown in Table 9.2.

Table 9.2 Performance Requirements for Urinals Performance Property Performance Requirements

Flushing test for single stall wall-hung urinals


Splash test for urinals The urinals shall not splash water onto the floor.


requirements specified in the Australian/New Zealand Standard No. AS/NZS 3982:1996 – Urinals.

9.3 Technical Specification on Workmanship


9.3.1 It is advisable to install extra strainers before the flushing valves’ water filters so as to prevent potential blockage of the water filters by solid particles such as silt and rust, in the flushing water.





9.3.3 Fix urinals as follows:

(c) Wall type (i) Fix bowl and division to wall with brackets, concealed hangers or

screws, as required.



10 Proposed Technical Standard for Toilets/lavatory Equipments

10.1 Scope

10.1.1 This proposed standard specifies the water efficiency grading and performance requirements together with test methods for toilets/lavatory equipments.

10.1.2 In this proposed standard, “toilets/lavatory equipment” means:

(a) a toilet suite; or (b) a water closet pan; or (c) a water closet cistern; or (d) a combination of a water closet and cistern


10.2.1 The water efficiencies of the toilets/lavatory equipment are rated to different grades according to their volume of discharge as shown in Table 10.1. Level 1 is the most water efficient whereas Level 3 is the least water efficient (Good). Level 4 is not classified as a water efficient toilets/lavatory.

Table 10.1 Conversion of Volume of Discharge to Water Efficiency Grades for

Toilets/lavatory equipment Volume of Discharge

f (litre) Water Efficiency Grade


f > 7.5 Level 4 10.2.2 If the tested toilets/lavatory equipment cannot fulfill the performance requirements

specified in Section 10.3 below. The toilets/lavatory equipment will be classified as Level 4.

10.3 Test Parameters and Methodology

10.3.1 The volume of discharge for full-flush and reduced-flush (if any) of the toilets/lavatory equipment shall be tested in accordance with the testing methodology specified in AS/NZS 1172.1:2005 and AS/NZS 1172.2:1999. The toilets/lavatory equipment are then rated to different grades according to the equivalent volume of discharge test results subject to the compliance with other performance requirements as shown in Table 10.2.



Table 10.2 Performance Requirements for Toilets/lavatory Equipment Performance Property Performance Requirements

Full-flush test on water closets








10.3.2 The toilets/lavatory equipment shall be designed and manufactured under a design

and production system operating according to a recognized international quality system (such as ISO 9001).


10.4.1 The testing is to be carried out either by an independent testing laboratory or by the manufacturers or the importers or other related parties themselves at their own testing laboratories. The results and certificates issued by the testing laboratories which fulfils one of the criteria as specified in Sections 10.4.2, 10.4.3 or 10.4.4 will be accepted.

HOKLAS laboratories






(c) The manufacturer’s or importer’s or other related parties’ in-house laboratory has been successful in carrying out tests on toilets/lavatory equipment and where these tests have been evaluated and certified by internationally recognised third party certification organisations.



Other laboratories

10.4.4 A laboratory which achieves HOKLAS accreditation (or is accredited by a scheme with which HKAS has concluded a mutual recognition agreement) for laboratory testing of plumbing fixtures and water-consuming appliances other than the tests stipulated in the Scheme, and the laboratory can demonstrate capability of carrying out tests on toilets/lavatory equipment in accordance with AS/NZS 1172.1:2005 and AS/NZS 1172.2:1999.



11 Proposed Technical Specification of Toilets/lavatory Equipment


11.1.1 It is recommended to use Level 1 (Excellent) water efficiency toilets/lavatory equipment in the toilets of all new buildings except hospitals.

11.1.2 The flushing water volume is reduced. If the trap outlet of toilets/lavatory

equipment is not connected with the anti-syphonage pipe, then the sewage cannot be drained away easily. This issue is expected to be prevented in new buildings, as every anti-syphonage pipe in buildings shall be connected with the trap outlet of toilets/lavatory equipment, regulated by Building (Standards of Sanitary Fitments, Plumbing, Drainage Works and Latrines) Regulations [Hong Kong Law Chapter 123I].

11.2 Technical Specification on Materials

Hong Kong Waterworks Standard Requirements for Plumbing Installation in

Buildings

11.2.1 According to Hong Kong Waterworks Standard Requirements for Plumbing Installation in Buildings Feb 2004 Version, issued by WSD, the water discharge mechanism of flushing devices shall either be one of the following types: (a) with a flushing cistern:

(i) valveless siphonic; (ii) drop valve; (iii) flap valve; or (iv) dual flush valve;

(b) without a flushing cistern: (i) flushing valve (flushometer valve).

They can either be actuated by mechanical means or by sensors.

11.2.2 Every flushing cistern shall have an overflow terminating in a conspicuous position.

11.2.3 The discharge volume of the flushing devices shall be preset at the smallest compatible with the toilet bowl to ensure that effective clearance can be achieved by a single flush of water.

11.2.4 The requirements on the use of valve type flushing cisterns (refer to paragraphs 11.2.1(a)(ii), (iii) and (iv) above) are as follows: (a) The valve seal of the flushing devices shall be easily replaceable. (b) A dual flush valve which is designed to give two different volumes of flush

shall have a readily discernible method of actuating the flush at different volumes. Such method should be illustrated clearly and permanently displayed at the cistern or nearby.

(c) For dual flush devices, the reduced flushing volume shall not be more than two-thirds of the larger flushing volume.

(d) The components of all valve type flushing devices shall be resistant to salt water corrosion.

(e) The flushing devices must pass the 200,000-cycle endurance test.



11.2.5 For an existing building with permission to use mains water (fresh or salt) for flushing purposes, any existing flushing apparatus found unsuitable shall be replaced with a proper apparatus as specified above.

11.2.6 It is the requirement under the Buildings Ordinance [Hong Kong Law Chapter 123]

that all new buildings shall be provided with a plumbing system to supply water for flushing purposes and every part of such plumbing system (including the storage tank) shall be constructed of such materials that are suitable for use with salt water.


11.2.7 This sections of technical specification makes reference to the General Specification for Building (2007 Edition) issued by ASD.

11.2.8 Flushing valve shall be corrosion resistant, made of brass, stainless steel or high

grade thermoplastics and activated by simply pressing on a push-button or lever. The volume of water per flushing cycle for water closet fitment shall be ranging from 7.5 litres to 15 litres. In the case of urinals, the discharge volume shall be not less than 4.5 litres for every basin or stall, or for every metre of a trough urinal. The flow rate of the flush water shall be adjustable. The flush valve to maintain a minimum of 1.5 litres/second flow rate.

11.2.9 W.C. pans shall be vitreous china washdown with horizontal outlet to BS 5503: Pt 3 or BS 5504: Pt 4, white plastic single ring seat and cover with plastic fixing bolts all to BS 1254 and flushing cistern to BS 7357, complete with 7.5 litres max capacity flushing apparatus, discharge pipe, ball valve and overflow, of one of the following types as specified: (a) Low level plastic. (b) High level plastic. (c) Low level vitreous china. (d) Close coupled vitreous china Sensor valve where specific for automatic flushing shall conform to BS EN 12164’sCW602N. Operating pressure shall be 0.5-10 bar rinse. Time-off control approx. 10 sec. and remote adjust from 1.5-30 sec. Dry battery shall be 6V Lithium 2 CR5. A/C operation shall be 220 to 230/50z; voltage 6V. Sensor fittings shall be suitable for use in salt water application.



11.2.11 The WC pan shall be tested for conformity with the performance requirements as

shown in Table 11.1.



Table 11.1 Performance Requirement for WC Pan Reference to the Specification Library

2008 Edition Items Method Acceptance Standards Functional Dimensions BS 5503:Part 3:1990: Table

1 and Fig. 2 BS 5503:Part 3:1990: Table 1 X: refer to Drawings

Visual Examination BS 3402:1969:Cl. 5.1 & 5.4 BS 3402:1969:Cl. 5.1 & Table 1.

Water Absorption BS 3402:1969:Cl. 6 & App. A.

BS 3402:1969:Cl. 6.

Crazing BS 3402:1969:Cl. 7 & App. B.

BS 3402:1969:Cl. 7.

Chemical Resistance BS 3402:1969:Cl. 8 & App. C.

BS 3402:1969:Cl. 8.

Resistance to Staining and Burning

BS 3402:1969:Cl. 9 & App. D.

BS 3402:1969:Cl. 9.

11.2.12 The cistern shall be tested for conformity with the performance requirements as

shown in Table 11.2. Table 11.2 Performance Requirement for Cistern Reference to the Specification Library

2008 Edition Items Method Acceptance Standards Dimensional Test on:

- Shell Thickness BS 7357:1990:Cl. 5.1.3. BS 7357:1990:Cl. 5.1.3. - Spill-over Level BS 7357:1990:Cl. 12 & Fig.

1. BS 7357:1990:Cl. 12

- Warning Pipe Connections

BS 7357:1990:Cl. 13.1. BS 7357:1990:Cl. 13.1.

Visual Examination BS 3402:1969:Cl. 5.2 & 5.4. BS 3402:1969:Cl. 5.2 & Table 2. (requirements on discolouration and polishing marks do not apply to the back of the cistern.)

Operating Mechanism Test BS 7357:1990:Cl. 17.1, 17.3 & App. H.2.

BS 7357:1990:Cl. 17.1 and 17.3

Flushing Apparatus Torque Test

BS 7357:1990:Cl. 8 & App. D BS 7357:1990:Cl. 8

Hydraulic Pressure Tests - Static Pressure BS 1212:Part 3:1990:Cl. 14.1 BS 1212:Part 3:1990:Cl.

14.1 - Shut-off Pressure BS 1212:Part 3:1990: Cl.

14.2 & App. D BS 1212:Part 3:1990: Cl. 14.2

- Dynamic Pressure on Discharge Arrangement

BS 1212:Part 3:1990: Cl. 14.3 & App. E

BS 1212:Part 3:1990: Cl. 14.3

11.2.13 The completed assembly shall be tested for conformity with the performance

requirements as shown in Table 11.3.



Table 11.3 Performance Requirement for Completed Assembly Reference to the Specification Library 2008 Edition

Items Method Acceptance Standards Flushing Test BS 7358:1990:Cl. 8 & App. A BS 7358:1990:Cl. 8 Volume of Discharge per Flush

BS 7358:1990:Cl. 9 & App. B 7.5 +1.0, -0.0 Litres

11.2.14 The performance requirement indicated in red and bold is recommended to be

relaxed. The requirement on flush volume is not necessary if other performance requirements of water saving toilets/lavatory equipment are fulfilled.


11.2.15 The volume of discharge for full-flush and reduced-flush (if any) of the toilets/lavatory equipment shall be tested in accordance with the testing methodology specified in AS/NZS 1172.1:2005 and AS/NZS 1172.2:1999. The toilets/lavatory equipment are then rated to different grades according to the equivalent volume of discharge test results subject to the compliance with other performance requirements as shown in Table 11.4.

Table 11.4 Performance Requirements for Toilets/lavatory Equipment









11.3 Technical Specification on Workmanship



11.3.2 Fix W.C. pans as follows:

(a) Pedestal type (i) Bed W.C. pans on concrete floors in white lead putty or other non-

hardening compound. If cement mortar is used for bedding, it shall be



not richer than 1:6, and a thin layer shall be applied only to that part of the pedestal which is in contact with the floor. Fix with No. 14 SG round-headed brass screws 70 mm long with domed plastic inserts in colour to match to fixture.

(ii) Joint W.C. pans to soil or drain pipes with approved PVC W.C. pan connectors to BS 5627 or other approved type.

(c) Wall hung type (i) Fix wall hung type WC pans to load bearing walls or support frame by

non-ferrous fixing bolts. Water tight seal between the walls and the edge of the W.C. pans shall be made by appropriate sealant.



12 Proposed Technical Standard for Showers

12.1 Scope

12.1.1 This proposed standard specifies the water efficiency grading and performance requirements together with test methods for showers.

12.1.2 A shower may include the showerhead and the accessories such as fixed or pivot

arm, a flexible hose (with or without a flow controller), tap top assemblies or other components, which is used solely for personal bathing. There are different types of showers available in the markets, such as: (a) wall mounted shower and (b) hand shower


12.2.1 The water efficiencies of the showers are rated to different grades according to their nominal flow rates as shown in Table 12.1. Level 1 is the most water efficient whereas Level 3 is the least water efficient (Good). Level 4 is not classified as a water efficient toilets/lavatory.

Table 12.1 Conversion of Nominal Flow Rates to Water Efficiency Grades Nominal Water Flow Rate

f (L/min) Water Efficiency Grade

f ≤ 9.0 Level 1 (Excellent) 9.0 < f ≤ 12.0 Level 2 (Very Good)

12.0 < f ≤ 16.0 Level 3 (Good) f > 16.0 Level 4

12.2.2 If the tested showers cannot fulfill the performance requirements specified in

Section 12.3. The showers will be classified as Level 4. 12.3 Test Methodology

12.3.1 The nominal flow rates of the showers shall be tested in accordance with the testing methodology specified in AS/NZS 3662:2005. The showers are then rated to different grades according to the nominal flow rate test results subject to the compliance with other performance requirements as shown in Table 12.2.



Table 12.2 Performance Requirements for Showers




Temperature drop The temperature drop shall not exceed 3 °C.

Endurance of the flow controller (if incorporated in a shower or being a component of a shower)


12.3.2 The showers shall be designed and manufactured under a design and production



12.4.1 The testing is to be carried out either by an independent testing laboratory or by the manufacturers or the importers or other related parties themselves at their own testing laboratories. The results and certificates issued by the testing laboratories which fulfils one of the criteria as specified in paragraphs 12.4.2, 12.4.3 or 12.4.4 will be accepted.

HOKLAS laboratories






(c) The manufacturer’s or importer’s or other related parties’ in-house laboratory has been successful in carrying out tests on showers and where these tests have been evaluated and certified by internationally recognised third party certification organisations.

Other laboratories

12.4.4 A laboratory which achieves HOKLAS accreditation (or is accredited by a scheme with which HKAS has concluded a mutual recognition agreement) for laboratory testing of plumbing fixtures and water-consuming appliances other than the tests



stipulated in the Scheme, and the laboratory can demonstrate capability of carrying out tests on showers in accordance with AS/NZS 3662:2005.



13 Proposed Technical Specification of Showers


13.1.1 To resolve the compatibility problem, it is recommended: (a) To maintain a water supply pressure of at least 150kPa at the cold water inlet

of the individual water heater in all new buildings; (b) To limit the variation of the actual flow rates for each water efficiency shower

under pressures between 150 kPa and 350 kPa to within ±1 L/min of the nominal flow rate as determined in the flow rate test; and


13.1.2 It is recommended to use Level 1 (Excellent) water efficiency showers in the toilets

of all new buildings except hospitals. 13.1.3 The designers of the buildings should contemplate the issue of flexibility in

temperature adjustment and the minimum flow rate requirement to trigger the water heater.

13.1.4 In general, all grades of water efficient showers are applicable to flow controlled

type water heaters. 13.1.5 Only water efficient showers with water flow rate no less than 7 L/min under inlet

pressure of 150kPa at shower head are suggested to be used in conjunction with pressure controlled type water heaters and no water efficient showers are recommended for electric water heaters which have relatively fairly high minimum flow rate requirement.

13.1.6 In case of storage type electric water heater which has no minimum flow rate

requirement, all grades of water efficient showers with generally no hampering of flexibility in water temperature adjustment are recommended.

13.2 Technical Specification on Materials



13.2.2 The showers shall be tested for conformity with the performance requirements as




Table 13.1 Performance Requirement for Showers Reference to the Specification

Library 2008 Edition Items Method Acceptance Standards Pressure Drop Test Refer to Method No. 2 as

given in (d)(iii) in the Specification Library 2008

Total combined pressure loss across shower hose and shower head shall not be more than 0.75 bar at 7 litre/minute

Hot Water Resistance Test Refer to Method No. 3 as given in (d)(iv) in the Specification Library 2008

No visual defect e.g. melting of any component. The sample shall be able to pass Pressure Drop Test after being cooled for 5 minutes. No leakage or defect found in hydraulic test.

13.2.3 The performance requirement indicated in red and bold is recommended to be

relaxed. The requirement on pressure drop is indispensable only at locations with low water pressure. The number of these locations is expected to be minimal in the government buildings, municipal venues and schools. It can be technically overcome by installation of booster pumps for those locations with low water pressure. The requirement on pressure drop is necessary to be relaxed in order to use water efficient showers. Specification developed from the proposed standard

13.2.4 The water supply pressure at the cold water inlet of the individual water heater is maintained at no less than 150 kPa for mixer taps.

13.2.5 The showers shall be tested for conformity with the performance requirements as


Table 13.2 Performance Requirements for Showers Performance Property Performance Requirements




Temperature drop The temperature drop shall not exceed 3 °C. Endurance of the flow controller (if incorporated in a shower or being a component of a shower)



requirements specified in the Australian/New Zealand Standard No. AS/NZS 3662:2005 – Performance of Showers for Bathing.



14 Summary of the Recommended Grades for Various Water Saving

Devices

14.1 Summary of the Recommended Grades

14.1.1 The recommended water efficiency grades of the water saving devices, including taps, urinals, toilets and showers, to be used in the recommendation are summarized in Tables 14.1 to 14.3.

Table 14.1 Recommended Grades of Non-Mixer Taps and Mixer Taps

Various Water Saving Devices

Recommended Levels


Other Concerns

Non-Mixer Taps Level 1 # Nominal flow rate: ≤ 2.0 L/min for taps

Level 1 #,* Nominal flow rate: ≤ 5.0 L/min Applicable to storage type water heaters

Level 2 #,* Nominal flow rate: 5.0 L/min < f ≤ 7.0 L/min Applicable to storage type and flow-controlled water heaters

Mixer Taps

Level 3 #,* Nominal flow rate: 7.0 L/min < f ≤ 9.0 L/min Applicable to storage type, flow-controlled and pressure-controlled water heaters


• Lower water efficiency levels may be considered if more concerns about hygiene in some critical applications, like clinics or elderly centres;

• Longer time will be required for filling up containers;

• Lower water efficiency levels may be considered if the afore-mentioned issue is very critical to their operations.

• From the environmental perspective, taps equipped with energy saving features, such as solar panels to drive the electronic sensors, shall be encouraged to use.

• In respect of the taps with automatic shut-off devices, the time for the tap to be closed should be as short as possible in order to minimize the water wastage. Taps with maximum closing time of no more than 1 min are recommended.




* An extra merit is proposed for using mixer taps with nominal flow rates of not more than 2 L/min

Table 14.2 Recommended Grades of Urinals and Toilets/lavatory equipment Various Water Saving Devices

Recommended Levels


Other Concerns

Urinals Level 1 Volume of discharge: f ≤ 1.5 L/unit

• Trough urinals are not recommended as water efficiency urinals for new buildings;

• Adequate space shall be allocated to accommodate enough number of wall-hung urinals;

• A reduced flush mode can be automatically activated when urinals are used frequently in public toilets with high volume usage;

• It is advisable to install extra strainers before the flushing valves’ water filters so as to prevent potential blockage of the water filters by solid particles such as silt and rust, in the flushing water.

Toilets/lavatory equipment

Level 1 Equivalent volume of discharge: ≤ 3.5 L (reduced flush: ≈ 3 L; full flush: ≈ 4.5 L)

• Squat toilets are not recommended as water efficiency toilets for new buildings;



Table 14.3 Recommended Grades of Showers

Various Water Saving Devices

Recommended Levels


Other Concerns

Showers Level 1 Nominal flow rate: ≤ 9.0 L/min

• The water supply pressure is maintained at the cold water inlet of the individual water heater at no less than 150 kPa.

• The designers of the buildings should contemplate the issue of flexibility in temperature adjustment and the minimum flow rate requirement to trigger the water heater.

• In general, all grades of water efficient showers are applicable to flow controlled type water heaters.

• Only water efficient showers with water flow rate no less than 7 L/min under inlet pressure of 150kPa at shower head are suggested to be used in conjunction with pressure controlled type water heaters and no water efficient showers are recommended for electric water heaters which have relatively fairly high minimum flow rate requirement.

• In case of storage type electric water heater which has no minimum flow rate requirement, all grades of water efficient showers with generally no hampering of flexibility in water temperature adjustment are recommended.



Part 4 – Comments from Various Bodies



15 Comments from Various Bodies

15.1 Overview

15.1.1 A briefing on the proposed technical standards was held on 1st June, 2009 at the Headquarter of WSD. Representatives from various bodies, WSD, the Architectural Services Department (ArchSD), the Housing Department (HD) and the Hong Kong Housing Society (HKHS) attended the briefing. The purpose of this briefing is to get the view towards the proposed technical standards.

15.2 Details of Comments

15.2.1 Details of the comments from WSD are illustrated in Table 15.2.

Table 15.1 Comments from WSD Comments from WSD Our Responses

General Comment Should the report be written so that any reader need not make reference to the report previously completed under the retrofitting project? The report can then be issued as an independent document.

The previously circulated report is the draft of the executive summary. The report is revised and it is feasible to be issued as an independent document.

Page 1, Section 1.1.3 Please clarify that bathroom taps are included. There may be misunderstanding on points (a) and (b).

The bathroom taps are proposed to be included in this standard. This paragraph is revised to clarify this issue.

Page 6, Table 2.4 Please clarify on the criteria for assessing the “availability in local market”. This comment will similarly apply to the other water saving devices.

In general, Level 1 water saving devices is recommended from the perspective of water saving unless there are technical applicability problems or inadequate local availability hindering the use of Level 1 devices (such as mixer taps). The aim of this table is a general comment on the availability in local market. It is expected the market will be also changed after the release of this technical standard.

Page 10, Section 2.9.2 Please provide the reference for the compatibility test. In general, a reference list should be provided in the Main Report.

The reference of the compatibility test and the list of reference are added.

Page 10, Section 2.9.4 Figure 5.1 should read as Figure 2.1

The report is revised accordingly.

Page D-4, A4(k), A5(c) Please include 50 kPa

The water supply pressure at the cold water inlet of the individual water heater in all new buildings is proposed to be maintained at no less than 150kPa. The nominal flow rate is the average values of the measured water flow rates under pressure of 150, 250 and 350 kPa. It would be in voluntary basis to include 50 kPa. If a shower is graded using WELS of Hong Kong, this pressure will be included.



Comments from WSD Our Responses

Appendices A to D Are these necessary to be appended to the Executive Summary? Have agreement / approval been obtained from the necessary authority for reprinting these testing guidelines in the report?

The test procedures are made reference to various Australian standards. With reference to other technical specifications in Hong Kong, the details of the test procedures are not included in this report.

15.2.2 Details of the comments from ArchSD are illustrated in Table 15.2.

Table 15.2 Comments from ArchSD Comments from ArchSD Our Responses

A. General (i) As the implementation of these technical standards would

involve revision of various requirements and specifications, the tentative implementation programme should be defined. For your information, ArchSD is reviewing our General Specification for Buildings 2007 Edition which is targeted to complete by end of 2010;

(ii) The relaxation of the specification and WSD’s requirements should be at the same time;

(iii) The market availability of these water saving devices should be considered;

(iv) The standards should have correlation with the relevant green building performance assessment tools;

(v) The way of giving extra merit should be defined to encourage more green initiative.

As discussed in the briefing, it is desired to review the technical specification from all interested parties in order to come up an unified technical specification. We also agree that the relaxation of the specification and WSD’s requirements should be done at the same time in order to encourage the use of water saving devices. We agree that the proposed standard should be announced earlier to the trades to make sure there are enough suppliers of water saving devices in the market. Any merit related to the use of water saving devices is encouraged.

B. Tap (non-mixed type) Tap of flow rate < 2L/min. is not common in the HK market (tap of lowest flow rate is 3 L/min). Please review the result of the Voluntary Water Efficiency Labelling Scheme; or otherwise the proposed standard should be announced earlier to the trades so that suppliers can obtain the required water efficiency label for the taps when the standard is implemented.

We agree that the proposed standard should be announced earlier to the trades to make sure there are enough suppliers of water saving devices in the market. From the experience of the water saving project, there is a number of tap available in the market with flow rate less than 2 L/min .

C. Tap (mixed type) Referring to Table 2.9 – it is suggested to include changing rooms for sports centre, sports ground and swimming pool, toilets for auditorium, and concert hall as examples for level 2, as these are “facilities which have peak demand of water and where prolonged queueing time is required in case of low water flow rate”.

The table is a suggestion of the application of various grades of water saving taps. The party can choose a suitable grade of water saving tap according to the preference of the users.

D. WC Dual flush WC with 4.5 L (full) is not common in the HK market (usually is 6 L (full)), the proposed standard should be announced earlier to the trades so that suppliers can obtain the required water efficiency certificate for the tap when the standard is implemented.

We agree that the proposed standard should be announced earlier to the trades to make sure there are enough suppliers of water saving devices in the market. From the experience of the water saving project, there is a number of dual flush WC with 3/4.5 L flush.



Comments from ArchSD Our Responses

Urinal & Toilet/lavatory Equipment (i) In Section 3.7 and Section 4.7, Level 1 urinals and Level 1

toilets/lavatory equipment are recommended for general use. From operation and maintenance point of view, it is suggested to include Level 2 and Level 3 to suit different applications similar to the recommendation for mixer and non-mixer taps in Table 2.9. In this regards, it is recommended to use Level 2 urinals and toilets/lavatory equipment for places with high volume usage and Level 3 for places having higher personal hygiene requirement;

(ii) In Section 3.5, it seems that most Level 1 urinals available in market are controlled by electronic sensors. Due to management and maintenance reasons, electronic sensors are usually not preferred by our client departments and are less widely used for urinals and toilets/lavatory equipment than for water taps. The recommendation in para (i) above will allow flexibility in selecting the water saving devices.

The technical standard established in this project will be on a voluntary basis. In general, Level 1 will be recommended from the perspective of water saving unless there are technical applicability problems or inadequate local availability hindering the use of Level 1 urinals or toilets/lavatory equipment. The actual level of water saving devices is dependent on various factors, such as actual locations and personal acceptance. An automatic shut-off mechanism is the key feature of a water efficient urinal. This automatic flushing control mechanism is not restricted to electronic sensors. A conscious activation by a user can also be classified as an automatic flushing control. As discussed previously, the selection of water saving devices level is flexible to suit for actual situations.



15.2.3 Details of the comments from HD are illustrated in Table 15.3.

Table 15.3 Comments from HD Comments from HD Our Responses

For mixers and shower heads The report recommends to have at least 150 kPa at the “Point of Use” for adaption of water saving mixers and shower heads. The consultant is requested to provide the definition of “Point of Use” for further discussion. For HA projects, we provide at least 170 kPa at cold water tap for water heater. Deducting the pressure loss of mixer (25 kPa) and shower hose & head (75 kPa), the output pressure is only 70 kPa. If “Point of use” is regarded at the final output from the shower head, we may need to double our minimum water pressure to cater for it, and which may result in unfavourably higher energy consumption. We have reservation in your suggestion to eliminate the maximum allowable pressure loss for shower hose and mixers from our Specification Library because we cannot control the output water pressure from the shower head for tenants. Alternatively, you may specify the maximum allowable pressure loss for mixers and shower heads in the grading system to ensure adequate water pressure and the expected flow rate that can be delivered to users for the proper operation of different types of water heaters. We have no comment to eliminate the compliance of mixer’s flow rate to BS 1415 from our Specification Library provided that WSD approves this relaxation.

The pressure in our study refers to water pressure at cold water inlet of the water heater. The report has been revised accordingly. A separate set of results have been prepared for the pressure drop across the water efficient taps and showers. In a meeting among WSD, EMSD, HD and HKPC on 9/7/2010, we presented the results and concluded that the pressure drops across current water saving showers are larger than the existing requirement set by HD. HD would relax its pressure drop requirement in order to allow the use of water efficient showers in its future projects. We also agree that the relaxation of the specification and WSD’s requirements should be done at the same time in order to encourage the use of water saving devices.



Comments from HD Our Responses

For toilets We have no comment on the suggested relaxation of the volume of discharge per flush for toilets (7.5 L) provided that WSD’s waterwork regulations can be met and the compliance with this specification would still result in effective flushing. For dual flush cistern, our preliminary observation from one of our pilot projects revealed that water consumption could be higher. The reasons behind might be due to improper use by our tenants, or existence of impurities in sea water that compromise the proper functioning of the flushing apparatus and result in water leakage. Hence a well planned and intensive public education on proper usage of dual flush cistern, together with a competent quality control regime that keeps tracking the performance of the water saving devices, should be built into the scheme.

From the experience of the water saving project, there is a number of dual flush WC with 3/4.5 L flush available in the market. From the experience of the water saving project, the impurities in sea water did affect the performance of the flushing cistern with sophisticated parts. We recommend the party concerned should contemplate the working capability of the flushing cistern taking into account the possible impurities of sea water. Promotional and educational campaigns such as advertisement or seminar are required to educate the public about the dual flush toilets. Besides, as excessive use of toilet paper increases the burden on water flushing, the public needs to be educated to have appropriate use of toilet paper so as to minimize the wastage of flushing water. To make dual flush cistern more user-friendly, stickers or labels should also be added to give a clear induction of flushing mode.

Testing guidelines On the recommended testing guidelines based on AS/NZS, it is desirable that the required testing services for the proposed performance requirements are available from HOKLAS laboratories to verify the products.

We agree that the proposed standard should be announced earlier to the laboratories to make sure there are enough HOKLAS laboratories to verify the products. Similar experience can be referenced to the promotion of WELS showers.

Grading of Taps The suggested application of the graded taps/mixers given in Tables 2.5 and 2.9 is too general and lacking backup studies. Perhaps a detailed study is required to establish a proper design guide for the graded taps and mixers. It should be noted that promulgation of water saving devices without a consolidated supporting guideline will be misleading and lead to confusion.

The table is a suggestion of the application of various grades of water saving taps. The party can choose a suitable grade of water saving tap according to the preference of the users.



15.2.4 Details of the comments from HKHS are illustrated in Table 15.4.

Table 15.4 Comments from HKHS Comments from HKHS Our Responses

1. Time frame for implementation of new technical standard for water saving device for new development shall be indicated in this proposal.

It is the first step of the development of the standard. As discussed in the briefing, all interested parties can further discuss the time frame for the implementation of this new technical standard.

2. In Table 6.2 of Section 6 (P.51), the toilet/lavatory equipment of Level 1 (i.e. equivalent volume of discharge ≤ 3.5L) is recommended. However, searching over the net, the commonly available dual flush toilets are models of 3L/6L, but not 3L/4.5L. Hence recommended level of toilet/lavatory equipment for new building should be Level 2 (i.e. 3.5 < f ≤ 4.5L) instead of level 1. If the standard of Level 1 is achieved, it is an extra merit.

From the experience of the water saving project, there is a number of dual flush WC with 3/4.5 L flush available in the market.

3. As discussed in the briefing , the pressure drop across the water tap and shower shall be provided for system design.

A separate set of results have been prepared for the pressure drop across the water efficient taps and showers.

4. As discussed in the briefing, the supply pressure at the point of use shall be amended to the supply pressure at the point of inlet to water saving device.

The pressure in our study refers to water pressure at cold water inlet of the water heater. The report has been revised accordingly.

5. Item 1.1.3 (a), elderly housing shall also be excluded for using water saving device for hygiene consideration

The reason of excluding toilets in hospital is the special requirements in plumbing appurtenance for hospitals. The table is a suggestion of the application of various grades of water saving taps. It is flexible to consider the use of water saving tap according to the actual locations.

6. Typing error: page 10, clause 2.9.4, line 2, should be Figure 2.1 instead of 5.1


7. Typing error: page 14, clause 2.12.6, line 2, should be Table 2.9 instead of 2.8


8. Typing error: page 46, clause 5.7.8 last sentence, Paragraph 5.4.5 shall be 5.7.5


9. Page 17, clause 2.13.2, the BS 1415, Part 1 or 2 is stated in the current WWO46 form (10/2004) for mixing valves (Notes 7 (i)). Amendment to Form WWO46 is required.

We agree that the relaxation of the WSD’s requirements should be done accordingly.

10. Incentive scheme shall be considered to promote water saving like Environment and Conservation Fund.

Any merit related to the use of water saving devices from external bodies is encouraged. We agree that the future promotion of this technical specification should take note this suggestion.

11. Award the Water Saving Certificate to the building shall be considered if all recommended levels of water efficiency are performed.

Any merit related to the use of water saving devices from external bodies is encouraged. We agree that the future promotion of this technical specification should take note this suggestion.



Part 5 – References



16 References

16.1 Literature References

Architectural Services Department (2007) “General Specification for Building”, 2007 Edition Centre for Health Protection Leaflet “Hand Hygiene – An Easy and Effective Way to Prevent Infection” printed in June 2009 HKPC (2010) “Consultancy for the Study of Compatibility Between Water Efficient Taps and Water Heaters”, Consultancy report Hong Kong Housing Authority (2008) “Specification Library”, 2008 Edition Pittet, D., Allegranzi, B. and Boyce, J. (2009) “The World Health Organization Guidelines on Hand Hygiene in Health Care and Their Consensus Recommendations”, Infection Control and Hospital Epidemiol, 30, 611-622 Water Supplies Department (2004) “Hong Kong Waterworks Standard Requirements for Plumbing Installation in Buildings” Feb 2004 Version 16.2 Key International Standards

AS/NZS 1172.1:2005 – Water closets (WC) – Pans AS/NZS 1172.2:1999 – Water closet (WC) pans of 6/3 L capacity or proven equivalent – Cisterns AS/NZS 3662:2005 – Performance of showers for bathing AS/NZS 3718:2005 – Water supply – Tap ware AS/NZS 3982:1996 – Urinals AS/NZS 6400:2005 – Water efficient products – Rating and labeling

Appendix 1

Extracts of Pressure Drop Test on Water Efficient Showers

Experimental setup of pressure drop test of water efficient showers

Pressure drop across water efficient showers

Town gas heater 1

(pressure-controlled) Town gas heater 2

(flow-controlled) LPG heater 1

(pressure-controlled) LPG heater 2

(flow-controlled)

Water Efficient Showers

Pressure at the inlet of

water heater (P1)

Pressure at P2 (kPa)

Total flowrate (L/min)







American Standard (WF-9028.000.50) (8.3 L/min)

150 120 5.8 135 6.4 130 5.8 135 6.4

Bellini (BL-JM-001-4) (7.3 L/min)

115 7.3 135 8 125 7.5 135 7.5

Delong (HS9014) (11.0 L/min)

115 6.6 135 7.5 115 6.5 135 7.5

EXQ (EXQ246CH) (9.4 L/min)

110 8 120 9 115 8.7 120 9

Kludi (KD607300500) (13.8 L/min)

100 9.8 110 11 105 9.5 110 10.7

Grohe (Tempesta Duo 28261000) (13.7 L/min)

100 11.5 110 11 100 7.5 110 10.7

Three Drop (B2C) (18.4 L/min)

90 10 110 10.5 100 9.5 110 10.2

Kims (T625) (20.6 L/min)

75 15 70 14 75 11.5 80 15

final report technical standard of water ......singapore, u.k. and u.s. therefore, this review...

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