m&e topic6b

8/11/2019 M&E Topic6b

1/57

8/11/2019 M&E Topic6b

2/57

Rahmat Muslim 2010

17/09/2014 BFC 3153 2

Presentation Outcomes

At the end of the presentation, student

should be able to :

Identify the different between Water

Efficiency & Water Conservation

Identify the suitable water efficiency

approach.

Design/Calculate the selected waterefficiency approach.

8/11/2019 M&E Topic6b

3/57

Rahmat Muslim 2010

17/09/2014 BFC 3153 3

Content

Introduction to WE & WC

Water Efficiency Approach

Rainwater Harvesting (RWH) Water Recycling

Water Efficient Irrigation

Water Efficient Fittings

Metering and Leak Detection System

8/11/2019 M&E Topic6b

4/57

Rahmat Muslim 2010

17/09/2014 BFC 3153 4

Water Efficiency

Introduction

8/11/2019 M&E Topic6b

5/57

Rahmat Muslim 2010

17/09/2014 BFC 3153 5

Efficiency vs Conservation

Water efficiency means using improved technologies andpractices that deliver equal or better service with less water.For example, the use of low-flow faucet (A regulator forcontrolling the flow of a liquid) aerators can be more powerful thanno aerators for washing hands.

Water conservation has been associated with curtailment ofwater use and doing less with less water, typically during awater shortage, such as a drought; for example, minimizing lawnwatering and automobile washing in order to conserve water.Water conservation also includes day-to-day demandmanagement to better manage how and when water is used,It is common to hear the words water conservation usedsynonymously with water efficiency.

8/11/2019 M&E Topic6b

6/57

Rahmat Muslim 2010

17/09/2014 BFC 3153 6

Water Resources

8/11/2019 M&E Topic6b

7/57 Rahmat Muslim 2010

17/09/2014 BFC 3153 7

Water Use

8/11/2019 M&E Topic6b


17/09/2014 BFC 3153 8

Drinking Water & Sanitation

8/11/2019 M&E Topic6b


17/09/2014 BFC 3153 9

Benefits of

Water Efficiency Programs

I. Reduced Water Demand Generally faster, cheaper and easier than supply-side

programs.

II. Water and Wastewater Treatment Saving Reduces costs and defers plant expansion.

III. Less Environmental Impact Due to fewer surface and subsurface withdrawals.

IV. Sustained Water Quality Reduces groundwaters contaminant intrusion and

curtails demand for new supplies that are of lowerquality.

8/11/2019 M&E Topic6b


17/09/2014 BFC 3153 10

Changing Behavior vs Equipment

Equipment changes may be viewed as apermanent fix to achieve water efficiency.

Changing employee behaviors, such as anoperating procedure, may be viewed as aquick and

inexpensive way to achieve similar savingswithout up-front capital expense.

In reality, both the technical and human side ofwater management issues must be addressed.

Consistenttraining and awareness in combinationwith proper tools and equipment will achieve morepermanent water savings.

8/11/2019 M&E Topic6b


17/09/2014 BFC 3153 11

10 Steps of Water Efficiency

Planning

Modify

Demand

Forecasts

Rank, Select

& Package

Measures

PerformCost/Benefit

Analysis

Identify

Feasible

Measures

Define

Efficiency

Potential

EvaluateExisting

Measures

Develop

Water

System

Profile

Review

Demand

Forecasts

Develop

a Workplan

& Budget

Combined

Estimated

Savings

8/11/2019 M&E Topic6b


17/09/2014 BFC 3153 12

Water Efficiency

Approach

8/11/2019 M&E Topic6b


17/09/2014 BFC 3153 13

Water Efficiency Approach

Rainwater Harvesting (RWH)

Water Recycling

Water Efficient Irrigation Water Efficient Fittings

Metering and Leak Detection System

8/11/2019 M&E Topic6b


17/09/2014 BFC 3153 14

Rainwater Harvesting (RWH)

The two (2) main approaches to RWH are

i) collection of runoff rainwater from surrounding site and

ii) collection of rainwater from roof top.

Both systems require separate water storage tanks and additionalpressure boosting equipment may be required.

Gravity fed system is encouraged to avoid additional energy use forpumping.

Use rainwater for non-potable applications such as toilets and urinalflushing, landscape irrigation, washing clothes etc.

Water purifying system may be necessary depending on theapplication and methodology of harvesting the rainwater.

Where rainwater filtration/purification is required, use of ozone oractivated oxygen in lieu of chlorine or other GHG chemicals, ispreferred to obviate negative environmental impact.

8/11/2019 M&E Topic6b


17/09/2014 BFC 3153 15

RWH in MalaysiaAwareness &

Potential Malaysia is endowed with far more rainfall than our water

demand when compared with other countries.

RWH could be an effective tool for helping to reduce theuse of treated water and provides a convenient buffer in

times of emergency or a shortfall in the public watersupply.

Malaysia received 990 billion cubic metre of rainwaterannually.

Surface runoff water account for 566bcu.m evaporatesand 64bcu.m end up as ground water

(Assoc Prof Ar Zuhairuse Md Darus)

8/11/2019 M&E Topic6b


17/09/2014 BFC 3153 16

Malaysia Rainfall AmountMay

2009

8/11/2019 M&E Topic6b


17/09/2014 BFC 3153 17

The Background

In March 2006, PM chaired and launched The NationalWater Resources Council with the two main agenda onRainwater and Groundwater.

For RWH, it was intended to formulate by-laws

nationwide to make it compulsory for bungalows,factories and schools/institutions to install RWH system

After 1998 drought, a study of alternative source of watersupply was being carried out.

1999, a Guideline for installing a RWH policy in Malaysiawas introduced which aimed to reduce dependence ontreated water.

8/11/2019 M&E Topic6b

18/57

8/11/2019 M&E Topic6b


17/09/2014 BFC 3153 19

Quality of Rainwater

The first rainfall may contain higher than averageamounts of accumulated dust, industrial pollutants,bird and animal droppings, leaves and otherdebris. It is recommended that, to prevent the risk

of potential contaminants adversely affectingrainwater quality and human health, the followingmeasures be implemented: Screened downpipe rainwater head of other suitable

leaf and debris device to be install on each downpipe.

To improve rainwater quality, a minimum of 20 litresper 100 sqm of the first flush of the roof catchmentneeds to be diverted/discarded before entering therainwater tank.

8/11/2019 M&E Topic6b


17/09/2014 BFC 3153 20

8/11/2019 M&E Topic6b


17/09/2014 BFC 3153 21

Rainwater Harvesting System

Developers can build rainwater

collection systems to collect

rainwater in their premises.

This applies to premises

located within water

catchments as well as thoseoutside water catchments.

Waterborne fees may be

charged as the used rainwater

that is discharged into sewers

will require proper treatmentand disposal. Computation of

waterborne fees is based on

tank size and expected usage.Collecting rainwater

8/11/2019 M&E Topic6b


17/09/2014 BFC 3153 22

Rainwater Collection Calculation

Rainfall Data from Malaysian Meteorological Dept. Local RainfallStations and responsible regulatory authorities (Refer Table 1).

Catchments sizesquare metres of the specific roof catchmentarea discharging to storage tank.

Pre-treatment - devices (first flush) that divert rainwater away

from storage tank. Coefficient runoff percentage from catchment area (Refer Table2).

Formula :

Max

amount

of rainfall

collected

(lit/year)

=

AnnualRainfall

(mm/yr)*

CatchmentArea

(m2)*

Runoff

Coefficient*

Percentage

Diverted

(%)

8/11/2019 M&E Topic6b


17/09/2014 BFC 3153 23

NEGERI Jan Feb Mac Apr Mei Jun Jul Aug Sep Okt Nov Dis Annual Stat

Johor 251.3 104.5 259.0 292.5 251.1 166.9 187.1 238.2 277.1 294.5 250.8 182.3 2755.3 Med

Kedah 16.7 22.4 133.7 219.7 174.2 110.8 204.7 202.7 315.4 373.3 233.4 60.5 2067.5 Med

Kelantan 81.5 21.6 72.6 98.9 178.1 113.1 188.7 185.3 353.7 244.6 707.7 414.3 2660.1 Med

Kuala Lumpur 169.0 184.0 0.0 294.4 0.0 151.3 96.5 172.7 268.8 294.0 198.4 151.3 1980.4 Med

Melaka 89.3 99.9 259.1 309.3 196.0 127.9 134.6 135.2 221.5 238.7 247.5 104.5 2163.5 Med

Negeri Sembilan 70.1 80.4 145.6 173.5 156.3 61.9 91.3 107.1 180.0 189.2 179.3 82.6 1517.3 Med

Pahang 333.6 61.7 230.5 169.7 213.0 146.8 146.1 161.0 257.1 244.7 465.0 481.1 2910.3 Med

Perak 120.8 90.6 113.0 159.8 174.0 74.4 102.6 103.0 226.6 270.4 189.6 94.8 1719.6 Med

Pulau Pinang 31.3 86.1 186.9 316.0 272.5 196.3 238.3 273.9 335.2 252.0 302.8 62.1 2553.4 Med

Perlis 13.1 28.2 104.3 203.2 193.1 157.1 260.4 273.5 353.1 246.4 186.4 49.0 2067.8 Med

Selangor 179.0 154.6 225.4 310.2 158.5 141.7 93.5 175.8 249.8 294.8 259.9 252.4 2495.6 Med

Sabah 158.6 142.3 100.9 179.9 304.2 254.9 254.2 376.5 374.6 396.2 477.4 181.1 3200.8 Med

Sarawak 490.0 94.5 200.5 192.0 251.5 85.0 111.5 161.0 89.5 463.0 307.0 631.0 3076.5 Med

Terengganu 89.7 21.6 96.6 115.4 103.2 92.8 82.0 104.6 202.7 241.0 846.5 357.4 2353.5 Med

Table 1Rainfall Data for Cities in

Malaysia

8/11/2019 M&E Topic6b

24/57

Rahmat Muslim 2010

17/09/2014 BFC 3153 24

Table 2Runoff Coefficient for

Differen Roof Types

Roof Type Runoff Coefficient

Pitched Tile Roof 0.9

Steel Roof 0.8

Flat Smooth Roof 0.5

Flat Gravel or Turf Roof 0.4

Asphalt/Smooth/Dense Pavement0.9

Block Pavement (Wide Joints) 0.7

Gravel Roadway 0.3

8/11/2019 M&E Topic6b

25/57

8/11/2019 M&E Topic6b

26/57

Rahmat Muslim 2010

17/09/2014 BFC 3153 26

Example : Calc of RWH Collection -

Selangor15m

12m

6m

4m9m

8m

DP-C

DP-B

DP-D

DP-A

HP

HP

HP

HP

LEGEND

Vertical Downpipe =

High Point = HP

Downpipe = DP

8/11/2019 M&E Topic6b

27/57

Rahmat Muslim 2010

17/09/2014 BFC 3153 27

Using Tangki NAHRIM Software

This software was developed for the RWH projects. The main purpose of this software is for predicting the size

of the rainwater tank to be used for a RWH system.

This software can generate the amount of rainwatercaptured, total rainwater volume delivered, reliability of the

system (= delivered volume / demand volume), coefficientof rainwater utilization, storage efficiency, percentage timeof tank empty.

Twenty years of rainfall data for different cities/townsthroughout Malaysia are available in this software.

This software is meant to be a guide in estimating the sizeof the rainwater tank with its respective reliability.

http://www.nahrim.gov.my/my/perisian-tangki-nahrim
http://www.nahrim.gov.my/my/perisian-tangki-nahrimhttp://www.nahrim.gov.my/my/perisian-tangki-nahrimhttp://www.nahrim.gov.my/my/perisian-tangki-nahrimhttp://www.nahrim.gov.my/my/perisian-tangki-nahrimhttp://www.nahrim.gov.my/my/perisian-tangki-nahrimhttp://www.nahrim.gov.my/my/perisian-tangki-nahrim

8/11/2019 M&E Topic6b

28/57

Rahmat Muslim 2010

17/09/2014 BFC 3153 28

Water Recycling

Water treatment systems and re-use technology optionsare acceptable for treating grey water and black water.The treated water is then recycled for use in irrigation,toilet flushing etc. Sand filters can be a cost effective

treatment technique.

POTENTIAL TECHNOLOGIES & STRATEGIES

Consider channeling grey water from sinks, showers andother sources to wastewater treatment plant.

Options for on-site wastewater treatment includepackaged biological nutrient removal systems and highefficiency filtration systems.

8/11/2019 M&E Topic6b

29/57

Rahmat Muslim 2010

17/09/2014 BFC 3153 29

Water Recycling

Recycling of Wastewater:

Grey Water

Black Water

8/11/2019 M&E Topic6b

30/57

Rahmat Muslim 2010

17/09/2014 BFC 3153 30

Types of Water Recycling

Treated & Untreated Greywater

Parameter Treated Greywater Untreated Greywater

Source Bath, Shower, Basin,

Laundry, Urinal and Kitchen

Bath, Basin, Shower and

Laundry

General Use Garden Irrigation, Laundry

Washing (cold water), ToiletFlushing and Vehicle Washing

Direct sub-surface garden

irrigation or surface application(usually through manual

bucketing)

Storage Storage of treated greywater

is allowedstored water

quality may need to bemonitored on an ongoing

basis

Storage Greywater system to

be emptied every 24 hours or

less depending on regulations

Approval &

Quality

8/11/2019 M&E Topic6b

31/57

Rahmat Muslim 2010

17/09/2014 BFC 3153 31

General Overview

Greywater generated by building occupants canbe recycled to provide a reliable source of waterfor activities that do not require drinking waterquality (eg irrigation, toilet flushing and general

washing).

Product approval certification, signage andlabelling or colouring of taps/pipes to indicatewater is recycled and not suitable for drinking.

Greywater is collected, stored and treated to thestandard specified by Local Authority.

8/11/2019 M&E Topic6b

32/57

Rahmat Muslim 2010

17/09/2014 BFC 3153 32

Table 3Volume of Wastewater Generated Per

Person in Malaysia (Usage Pattern in SelangorSWAn)

Wastewater Source

(Residential)

Volume Used

l/p/d l/p/y

Greywater (Untreated)

Shower 65 23,725

Basin 40 14,600

Cooking & Drinking 10 3,650

Washing Machine 45 16,425

Leaks 5 1,825

Total Greywater 165 60,225

Blackwater (Treated)

Toilet (WC) 65 23,725

8/11/2019 M&E Topic6b

33/57

Rahmat Muslim 2010

17/09/2014 BFC 3153 33

Calculation of Greywater Demand

and Availability Assume potable water

calculations for sewageconveyance for a officebuilding with a capacity of 300occupants.

The calculations are based ona typical 8 hours workday.

Take as 50% Male & 50%Female.

Male occupants are assumedto use WC once and urinalstwice.

Female occupants areassumed to use WC threetimes.

Table 4 Sample Fixture

Types and Capacity

Fixtures Types Litres

Conventional WC 6

Low-Flow WC 4

Composting Toilet 0

Conventional Urinal 6

Low-Flow Urinal 3

Waterless Urinal 0.02

8/11/2019 M&E Topic6b

34/57

Rahmat Muslim 2010

17/09/2014 BFC 3153 34

Table 5 Baseline Case

Fixture Type Daily Uses Flowrate (l) Occupants Sewage Generation (l)

WC (Male) 1 6 150 900

WC (Female) 3 6 150 2700

Urinals 2 6 150 1800

Total Daily Volume (l) 5400

Table 6 Design Case

Fixture Type Daily Uses Flowrate (l) Occupants Sewage Generation (l)

WC (Male) 1 6 150 900

Low-Flow WC 3 4 150 1872

Urinal-Flush 2 3 150 900

W/less Urinal 2 0.02 150 0

Total Daily Volume (l) 3672

8/11/2019 M&E Topic6b

35/57

Rahmat Muslim 2010

17/09/2014 BFC 3153 35

Volume of Water Storage Capacity Per

Person for Office Building(SYABAS Guidelines)

800 litres per 100 sq.m (GFA)

The actual percentage of savings from

recycled water shall be compared against

the total water storage capacity required

by local water authority.

8/11/2019 M&E Topic6b

36/57

Rahmat Muslim 2010

17/09/2014 BFC 3153 36

Water Efficient Irrigation

Design a water-efficient landscape by selectingnative or adaptive plants that require minimal water.

Reduce or eliminate use of potable water forlandscape irrigation system.


Perform soil / climate analysis to determineappropriate plant material and design the landscapewith native or adaptive plants to reduce or eliminateirrigation requirements. Where irrigation is required,use high efficiency equipment and/or climate basedcontrollers.

8/11/2019 M&E Topic6b

37/57

Rahmat Muslim 2010

17/09/2014 BFC 3153 37

Water Efficient

Irrigation/Landscaping Encourage the design of systems that do not

require the use of potable water supply from

local water authority.

Reduce potable water consumption forlandscaping irrigation by 50% (e.g. through

use of native or adaptive plants to reduce or

eliminate irrigation requirement), OR

Not use potable water at all for landscape

irrigation.

8/11/2019 M&E Topic6b

38/57

Rahmat Muslim 2010

17/09/2014 BFC 3153 38

WATER EFFICIENT PLANTS

Where applicable, use

drought resistant plants

or plants that fit

naturally into theexisting climatic

conditions including

rainfall and temperature

pattern and require littleirrigation.

Draught resistant plants

8/11/2019 M&E Topic6b

39/57

Rahmat Muslim 2010

17/09/2014 BFC 3153 39

WATER EFFICIENT PLANTS

The amount of turf area

should be limited as most

turf grasses need a lot of

water and require continual

upkeep. Group plants bytheir water needs such as

plants that need high,

moderate or little to no

irrigation rather than byappearance or functions.Limit turf area

8/11/2019 M&E Topic6b

40/57

Rahmat Muslim 2010

17/09/2014 BFC 3153 40

WATER EFFICIENT IRRIGATION

SYSTEM Irrigation system should be zoned so that plants with different types

of water needs are irrigated separately. For example, turf grassshould be watered separately from shrubs and flowers. Trees andshrubs that require little irrigation may only require water duringprolonged periods of dry season when they show signs of stress.For these plants, hand watering may be all that is required.

Water efficient irrigation system such as drip irrigation systemshould be used. Drip irrigation applies water slowly and directly tothe roots of plants through small flexible pipes and flow controldevices (called emitters). Since water is applied directly to the root,evaporation and runoff is minimized. The irrigation system usingpotable water is only permitted for system to be turned on manuallyand turned off automatically.

Automatic controller should be used to turn the irrigation system offand to control the water flow through the various zones according toa pre-set schedule. Rain sensors should be incorporated toautomatically turn off irrigation system during raining days.

8/11/2019 M&E Topic6b

41/57

Rahmat Muslim 2010

17/09/2014 BFC 3153 41

Water Efficient Irrigation System

Rain

Sensor

Turn off irrigation

system

This project uses drip irrigation that

was activated based on time

schedule regardless of the weather.

By simply incorporating rain sensor to

shut the irrigation system off during

raining days, savings of 35% of water

a year were achieved.

Rain sensor to shut the irrigation systemDrip irrigation system

Drip irrigation uses 30% to 50% less

water than sprinkler irrigation

8/11/2019 M&E Topic6b

42/57

Rahmat Muslim 2010

17/09/2014 BFC 3153 42

Calculation of Water Use for

LandscapingLandscape Coefficient (KL) = Species Factor x Density Factor x Microclimate Factor

(Equation 1)

Project Specific Evaportranspiration Rate (ETL) = Evaportranspiration Rate (ETo) x KL

(Equation 2)

Design Case TWA (gal) = [Area (sf) x ETL/IE] x Controller Eff (CE) x 0.6233 gal/sf/in

(Equation 3)Design Case Total Potable Water (TPWA) (gal) = TWA (gal) x Reuse Water (gal)

(Equation 4)

Baseline Case TWA (gal) = Area (sf) x ETL/IE x 0.6233 gal/sf/in

(Equation 5)

Reduction of Potable Water (%) = (1Design TPWA/Baseline TWA)/100

(Equation 6)

Reduction of Total Water (%) = (1Design TWA/Baseline TWA) x 100

(Equation 7)

8/11/2019 M&E Topic6b

43/57

Rahmat Muslim 2010

17/09/2014 BFC 3153 43

Example : Calculation of Water

Efficient LandscapingAn office building with site area of 6000 sqft. The site consists of ground, mixedvegetation and turf grass. The whole site is irrigated with a combination ofpotable water and greywater harvested from the building.

Table 8 Landscape Factors

Vegetation

Type

Species Factor (Ks) Density Factor (Kd) Microclimate Factor (Kmc)

Low Avg High Low Avg High Low Avg HighTrees 0.2 0.5 0.9 0.5 1.0 1.3 0.5 1.0 1.4

Shrubs 0.2 0.5 0.7 0.5 1.0 1.1 0.5 1.0 1.3

Ground Cover 0.2 0.5 0.7 0.5 1.0 1.1 0.5 1.0 1.2

Turfgrass 0.6 0.7 0.8 0.6 1.0 1.0 0.8 1.0 1.2

Table 7 Irrigation Types

Irrigation Type IE

Sprinkler 0.625

Drip 0.9

8/11/2019 M&E Topic6b

44/57

Rahmat Muslim 2010

17/09/2014 BFC 3153 44

Table 9 Design Case

Landscape

Type

Area

(sqf)

Species

Factor

(Ks)

Density

Factor

(Kd)

Micro

climate

Factor

(Kmc)

KL ETL IETPWA

(gal)

Shrubs 1200 Low 0.2 Avg 1.0 High 1.3 0.3 2.11 Drip 2,815

Mixed 3900 Low 0.2 Avg 1.1 High 1.4 0.3 2.50 Drip 10,837

Turfgrass 900 Avg 0.7 Avg 1.0 High 1.2 0.8 6.82 Sprinkler 9,822

Total Plant Water Applied (gal) 23,474

Table 10 Baseline Case

Landscape

Type

Area

(sqf)

Species

Factor

(Ks)

Density

Factor

(Kd)

Micro

climate

Factor

(Kmc)

KL ETL IETPWA

(gal)

Shrubs 1200 Avg 0.5 Avg 1.0 High 1.3 0.7 5.28 Sprinkler 10,134

Turfgrass 4800 Avg 0.7 Avg 1.0 High 1.2 0.8 6.82 Sprinkler 52,384

Total Plant Water Applied (gal) 62,518

Therefore, comparison of the baseline to the designed building indicates a 62% reduction in irrigation

water volume used for landscape.

8/11/2019 M&E Topic6b

45/57

Rahmat Muslim 2010

17/09/2014 BFC 3153 45

Water Efficient Fittings

The use of water efficient water closets, wash

hand basins or shower heads or systems

which has the potential to reduce potable

water consumption in the building. Specify the use of automatic self-closing

faucets, electronic or otherwise, to eliminate

wastage through faucets left runningunnecessarily.

Specify the use of modified waterless urinals.

8/11/2019 M&E Topic6b

46/57

Rahmat Muslim 2010

17/09/2014 BFC 3153 46

Water Efficient Labelled Fittings

FITTINGS GOOD RATINGVERY GOOD

RATING

EXCELLENT

RATING

Shower Taps, Mixers &

Showerheads (L/min)>7 to 9 >5 to 7 5 or less

Basin Taps & Mixers

(L/min)

>4 to 6 >2 to 4 2 or less

Sink/Bib Taps (L/min) >6 to 8 >4 to 6 4 or less

Flushing CisternsDual

Flush Type (L/flush)

>4.0 - 4.5 (full flush)

> 2.5 -3.0 (low flush)

>3.5 to 4.0 (full flush)

> 2.53.0 (low flush)

3.5 or less (1)(full flush)

2.5 or less (low flush)

Urinals & Urinal Flush

Valve(L/flush)

> 1.0 to 1.5 > 0.5 to 1.0

0.5 or less (2)

Orwaterless urinals

(1) To pass laboratory simulation test on waste transportation efficiency in pipe. Source: PUB

(2) To pass dilution test.

WATER EFFICIENT FLUSHING

8/11/2019 M&E Topic6b

47/57

Rahmat Muslim 2010

17/09/2014 BFC 3153 47

WATER EFFICIENT FLUSHING

SYSTEM

Dual Flush LCFCs

Urinal Flush valve 0.5 litres

flush volume

Dual flush low capacity flushing cisterns should be used. Each flushing shoulduse 4.5 litres or less of water for a full flush and less than 3 litres for a half

flush.

Urinal flush valves that use not more than 0.5 litres of water per flush should be

used. This is the recommended flush volume for standard size urinal of 300mm

width.

8/11/2019 M&E Topic6b

48/57

Rahmat Muslim 2010

17/09/2014 BFC 3153 48

WATER EFFICIENT FIXTURES

A study (PUB) found that a flow rate of 2 litres/min at thewash basin taps in staff and public toilets is sufficient fornormal washing purpose. The lower flow rate will help toreduce water consumption and save on the water bills.

Sensor taps with a flow rate of 2 litres/min can also beinstalled. These taps should also cut off water supplywhen the hands are removed from under the tap, orwhen the preset timing of 30 or 60 seconds is reached,whichever is earlier.

Self-closing taps also help to prevent running tap afteruse. A combination of regulators and self-closing tapscan achieve significant savings.

E l f W t Effi i t

8/11/2019 M&E Topic6b

49/57

Rahmat Muslim 2010

17/09/2014 BFC 3153 49

Examples of Water Efficient

FixturesInstall self-closing delayed actiontaps (timing of between 2 and 3

secs) at all wash basins. The flow

rate should be 2 litres/min.

Install self-closing delayed actionshower tap (timing not exceeding 15

secs) at all showers. The flow rate

should not exceed 7 litres/min

(except for hotels).

8/11/2019 M&E Topic6b

50/57

Rahmat Muslim 2010

17/09/2014 BFC 3153 50

WATER EFFICIENCY LABELS

8/11/2019 M&E Topic6b

51/57

Rahmat Muslim 2010

17/09/2014 BFC 3153 51

Install constant flow regulators and

adjust flow rate to less than 6

litres/min for all bib taps and sink/

kitchen taps.

Flow rate can be reduced by simple

method such as fixing thimbles or

constant flow regulators

M t i d L k D t ti

8/11/2019 M&E Topic6b

52/57

Rahmat Muslim 2010

17/09/2014 BFC 3153 52

Metering and Leak Detection

System

Specify the provisions of sub-meters for majorwater consuming systems/equipment.

Incorporate EMS monitoring system of sub-meters.


To incorporate provisions of analogue or digitalflow water sub-meters.

Incorporation of EMS monitoring will enableearly detection of water leakage and containwater wastage.

8/11/2019 M&E Topic6b

53/57

Rahmat Muslim 2010

17/09/2014 BFC 3153 53

METERING & ACCOUNTING

Sub-meters BMS display

Sub-meters should be installed on all major water systems, such as cooling

tower, irrigation, hot water devices, etc. The readings taken can help to give abetter picture of water consumption in buildings and allow building owners

know how much water is consumed by the major water equipment. By

monitoring water usage, water saving opportunities can be identified. The main

and sub-meters should be linked to a building management system (BMS). By

linking the reading to BMS, water usage trends can be recorded. An alarm

could also be activated if there is a sudden increase in water consumption or anew trend in water consumption as this will indicate the possibility of a water

leakage.

COOLING TOWER WATER

8/11/2019 M&E Topic6b

54/57

Rahmat Muslim 2010

17/09/2014 BFC 3153 54

COOLING TOWER WATER

CONSUMPTION

Condensate water from

AHUs or FCUs could also

be used for cooling tower

make-up water. Using

condensate water from airside to top up cooling tower

water not only lowers its

water temperature to raise

chiller efficiency, it alsohelps to reduce the amount

of make-up water needed.Collecting condensate water from AHU

BETTER CYCLES OF

8/11/2019 M&E Topic6b

55/57

Rahmat Muslim 2010

17/09/2014 BFC 3153 55

BETTER CYCLES OF

CONCENTRATION

Cooling tower water treatment should be designed toachieve 6 or better cycles of concentration for waterbased cooling system. With the quality of water suppliedby PUB or NEWater, cycles of concentration of 6 orhigher are achievable.

Higher concentration cycles reduce make-up and blow-down water requirements and hence reduce the cost ofoperation.

The optimum concentration cycle should be decided in

consultation with the water treatment service provider.The potential for scale, corrosion, deposition andbiological fouling problems should also be considered.

8/11/2019 M&E Topic6b

56/57

Rahmat Muslim 2010

17/09/2014 BFC 3153 56

EFFICIENT DRIFT ELIMINATORS

Efficient drift eliminatorshould be used. Itshould restrict the driftloss to less than 0.02%

of cooling towerrecirculating water. Thedrift eliminators controlunnecessary loss of

water and help reducethe nuisance of waterspraying near the tower.

8/11/2019 M&E Topic6b

57/57

17/09/2014 BFC 3153 57

The End

m&e topic6b

Documents