define

Project Title : Improve Air Handling Unit PerformanceImprove Air Handling Unit Performance

Team Leader: Edgardo NacpilAssistant Leader : Oscar Roman

Members : Joselito Mendez (OAFA-FM)George Villamor (OAFA-FM)Eduardo de Veyra (OAFA-FM)William Seril (OAFA-FM)Arnel Allan Castro (OAFA-FM)Rommel Protacio (CPMI)Sonny Jose Marquez (CPMI)

Champion : Chatiya Nantham

DEFINEDEFINEProject Charter

Business Case:One of the key functions of OAFA-FM is to maintain a reliable indoor air quality to all offices in this headquarters building complex. So operating and maintaining air-conditioning and mechanical ventilation (MVAC) system plays an important part. It consumes about 44% of the overall energy consumption of the headquarters and its cost of operation and maintenance is also relatively high. Therefore, this system has to be operated and maintained efficiently in order to meet the international standards (ASHRAE and EPA ) of air quality.

This MVAC system consist of two sets of components, i) central refrigeration chillers in the plant room, cooling towers, chilled and condenser water pumps, a few kilometers of piping network, motorized and manual valves that provide cooling water( as a media) to remove the building heat from the offices/workplace and ii) air handling units, the office fan powered units and ventilation fans that supply fresh air and remove stale air from offices/workstations/meeting rooms and auditorium.

In this six sigma project, the primary focus is to improve and sustain the operating efficiency of the aging air handling units, 47 units altogether in the tower block, which are more than 18 years old until they are replaced in the next 3 to 5 years.

DEFINEDEFINEProject Charter

Problem Statement:There are 47 air handling units in the tower block that are more than 18 years old and owing to aging condition of these units, the operating efficiency have degraded overtime and this has to be reevaluated to ensure their performance can be sustained for the next 3 to 5 years of operations until replaced.

Project Goal:

Improve the current operating performance of the old AHUs to at least 80% of their design capacity

Project Scope:

The project will focus on improving the performance of 14 sample air handling units located at the office block which are measured to be operating below 31 tons or 80% of their design capacity.

DEFINEDEFINE

Chilled Water Distribution Piping

CORE 1

CHWP

S-9F

CORE 2

(SOUTH)

CORE 6

(EAST)

CORE 3

CORE 4

(WEST)

CORE 5(NORTH)

S-9D

S-9C

S-9A

S-9B

S-9E

COWP

COOLING TOWER

CHILLER

TOWER BLOCK

BOOSTER PUMP

BOOSTER PUMP

BOOSTER PUMP

BOOSTER PUMP

BOOSTER PUMP

Chilled Water Supply

Chilled Water Return

CENTRAL PLANT ROOM

LEVEL 10

LEVEL 9

LEVEL 8

LEVEL 7

LEVEL 6

LEVEL 5

LEVEL 4

LEVEL 3

LEVEL 2

LEVEL 1

LEVEL B1

BOOSTER PUMP

S-8F

S-8D

S-8C

S-8A

S-8B

S-8E

S-7F

S-7D

S-7C

S-7A

S-7B

S-7E

NOAS-6NOAS-4

NOAS-3

NOAS-1 NOAS-2

NOAS-5

S-1F

S-1D

S-1C

S-1A

S-1B

S-1E

S-2F

S-2D

S-2C

S-2A

S-2B

S-2E

S-3F

S-3D

S-3C

S-3A

S-3B

S-3E

S-4F

S-4D

S-4C

S-4A

S-4B

S-4E

S-5F

S-5D

S-5C

S-5A

S-5B

S-5E

S-6F

S-6D

S-6C

S-6A

S-6B

S-6E

S-B3

S-B1

S-B2

AHU ROOMCORE-

1

AHU ROOMCORE-

4

AHU ROOMCORE-

2

AHU ROOMCORE-

5

AHU ROOMCORE-

6

AHU ROOMCORE-

3

Main Duct Loop

Main Duct Loop

DEFINEDEFINE Typical AHU Layout

(Level 1 – Level 8)

E D

S A

A D

B

A V

E N

U E

OFFICE 1 OFFICE 2

AIR HANDLING

UNITFLOOR LEVEL

CO

OL

ING

CO

IL

CHILLED WATER SUPPLY

BLOWER

AIR

FIL

TE

R

CHILLED WATER RETURN

SH

UT

OF

F

DA

MP

ER

RE

TU

RN

AIR

PL

EN

UM

TH

ER

MO

ST

AT

PRESSURE GUAGE

THERMO METER

SHUT OFF DAMPER

CO2

SENSOR

MAIN SUPPLY AIR DUCT LOOP

FPU

F A N R O O M

OU

TS

IDE

AIR

(T

RE

AT

ED

&

PR

E-C

OO

LE

D)

CEILING

SUPPLY AIR DUCT TO OFFICE SPACE

FLOOR LEVEL

DEFINEDEFINE

Illustration of Air Handling Unit Operation

High Level Process Map

Schematic Diagram of AHU Operation

OA DAMPERRA DAMPERSA DAMPER

OPEN

MANUALON

TIMESCHEDULE

ON

AHU FANSTART

ONSTATUS

PRESSURIZED THE

MAIN DUCT

TEMP.SETTING

CHILLEDWATER

MOTORIZED VALVE

MODULATE

PITCHEDBLADEOF FAN

MODULATE

BMS

AHUFAN

SHUTDOWN

REQUESTFOR

EXTENSION

TIMESCHEDULE

OFF

OA DAMPERRA DAMPERSA DAMPER

CHW MVCLOSED

OFFSTATUS

When the supply fan is off, OA damper, discharge damper and the vane axial pitch blade shall be closed, the return air damper shall be open.

When the fan is on, the minimum outside air damper and return air damper shall be 100% open, the maximum OA damper shall be closed and the static pressure shall modulate the vane axial pitch blade to maintain set supply duct pressure as sense by the duct static pressure sensor, fan shall not start until minimum OA damper and discharge damper have been open by end switches.

The discharge air temperature shall modulate the cooling coil control vane to maintain the desired discharge air temperature.

DEFINEDEFINE High Level Process Map

OAFA-FM

Chilled Water Mixed AirAir FilterFan MotorCooling CoilsBest Practices

Heat TransferAir FlowWater FlowFiltration

Efficient Operationof Air Handling Units

ADB

SUPPLIER CUSTOMEROUTPUTINPUT PROCESS

DEFINEDEFINE SIPOC Diagram

High Level Need:

Improved and reliable performance

Output Unit

Output Characteristic ( Big Y )

Efficient Operation

Improved capacity of inefficient air handling units to an average of 80% of design or 31 tons

Project Y ( Little Y )

Measure

Specification Limits

Operations definition of process to be measured

Conduct performance verification of the capacity of the air handling units

Operating condition of the air handling units

Design capacity of each air handling units in tons (38.6T)

Target

Defect

No. of defect opportunities per unit.

C

T

Q

1 opportunity for a defect per measurement of improved performance

How process will be measured:

The units shall be in set to full operating condition.

Air Handling unit capacity less than 31.0 tons .

DEFINEDEFINE CTQ Matrix

Performance Verification Report Form to Measure the Capacity of Air Handling Unit

Air Handling Unit Air Side a. Date b. Fan Number c. Fan Speed d. Pressure drop across filter e. Pressure drop across coil f. Fan suction static pressure g. Fan discharge static pressure h. Fan motor amperage i. Rated motor amperage and voltage rating j. Re-circulating airflow (lps) k. Outside Airflow (lps) l. Outside Air condition/state (DB, WB) m. Return Air condition/state (DB, WB) n. Entering Coil condition/state (DB, WB) o. Leaving Coil condition/state (DB,WB) p. Fan discharge condition/state (DB,WB)

NOTE: Report form shall contain the following minimum data. Listings shall include design and actual conditions of each air handling unit (supply, outside air, and re-circulation) and water system.

How Process Is Measured

Air Handling Unit Air Side a. Record date and time of test b. Outdoor conditions at time of test c. Test and record motor load in amperage d. Fully open all accessories and set the fan at full load f. Measure and record the re-circulated air (lps) g. Measure the design OA (lps) h. Record entering and leaving air thru coil (DB, WB) i. Record the pressure drop across the filter j. Record the pressure drop across the coil

Air Handling Unit Water Side a. Open manually the motorized valves full open position b. Set temperature controls so coils are calling for full cooling. c. Record the chilled water supply and return temperature d. Record the chilled water supply/return flow using portable ultrasonic flow meter. e. Record and check the pressure drop across the cooling coil.

DEFINEDEFINE CTQ MatrixProject Y (Little Y)

D M A I C

• Define 01 Jan 08 to 8 March 08• Measure 9 March 08 to31 March 08• Analyze 01 Apr 08 to 30 April 08• Improve 01 May 08 to 30 May 08• Control 01 Jun 08 to 30 Jun 08

DEFINEDEFINE Milestone/Timeline

Q = 9.53 x flow(lps) x (h1-h2)

Where:

Q = capacity in tons of refrigeration (TR)

h = enthalpy from psychrometric chart

flow = air flow thru coil (lps)

AHU PerformanceMEASUREMEASURE

Leaving Air

Temperature

RH

Velocity

Entering water

Temperature

Velocity

Leaving water

Temperature

Velocity

Entering Air

Temperature

RH

Velocity

Summary of Measured Parameters of AHUs Less Than 31.0 TR SUPPLY TO

MAIN DUCT

Enthalpy

DifferenceWATER SIDE

Flow (lps)EAT DB

(ºF)% RH

LAT DB

(ºF)

Pressure Drop

(in. WC max)SAT DB (ºF) H2 - H1 Flow (lps)

Typical AHU 2.3 38.638 4590 75.2 56.7 48 1.1 - 10.5 3.7

S-1E 3.20 25.688 3940 73.5 70.60 57.30 0.94 60.0 8.21 1.08

S-1F 1.70 26.854 3019 73.3 59.30 49.00 0.80 53.0 11.20 2.00

S-2F 2.73 30.124 4173 72.9 61.50 52.40 0.90 57.0 9.09 3.06

S-3A 2.02 30.044 3652 74.9 64.30 54.50 0.48 57.7 10.36 2.17

S-3B 2.40 28.485 3671 74.6 64.90 55.60 0.80 60.0 9.77 1.76

S-3C 2.90 19.911 4445 74.9 59.30 60.00 0.90 60.8 5.64 1.20

S-3D 3.00 29.621 4986 74.0 55.70 54.30 0.76 57.4 7.48 1.76

S-3E 2.65 28.079 4592 73.9 62.50 56.80 0.86 60.3 7.70 1.12

S-5A 2.70 30.537 5148 75.9 60.30 57.70 0.56 60.3 7.47 2.15

S-5B 2.38 24.126 4845 75.5 68.10 62.00 0.72 66.0 6.27 1.21

S-5E 2.67 28.170 4761 76.3 65.20 59.30 0.92 62.8 7.45 1.79

S-6F 2.92 29.961 4964 75.1 59.40 57.00 0.80 59.4 7.60 2.25

S-7E 2.40 30.331 5379 73.8 68.30 58.30 0.70 64.4 7.10 1.05

S-8A 1.69 26.257 3766 77.6 63.70 60.10 0.50 57.2 8.78 4.88

Equipment

Face

Velocity

(m/s)

Capacity

(TR)

AIR SIDE ACROSS COOLING COIL

AHU PerformanceMEASUREMEASURE

NOAS-1 NOAS-2 NOAS-3 NOAS-4 NOAS-5 NOAS-6

S-9A S-9B S-9C S-9D S-9E S-9F






OAS7 OAS8 OAS9 OAS10 S-3A S-3B S-3C S-3D S-3E S-3F

S17 S18 S19 S20 S21 S-10B S-10A S-2A S-2B S-2C S-2D S-2E S-2F

S13 S14 S15 S16 S-10D S-10C S-1A S-1B S-1C S-1D S-1E S-1F

BPUMP1 BPUMP2 BPUMP3 SB1 SB2 SB3

BPUMP4 BPUMP5 BPUMP6

Segment ASegment BSegment C

EAST CENTRAL

WEST

EAST WEST

EAST WEST

S11 S12

ASIAN DEVELOPMENT BANKAHU SYSTEM

26.2 37.3 33.4 36.9 31.1 39.5

31.6 36.3 31.0 32.6 30.3 35.7

31.1 31.9 33.5 35.8 32.4 29.9

30.0 28.5 19.9 29.6 28.0 32.2

BASEMENT 1 FANPOWERS

37.2 37.3 34.7 37.34

36.8 38.1

30.5 24.1 36.9 33.3 28.2 35.7

37.7 39.5 39.4 35.1 33.0 38.8

36 40.9 34.7 35.2 42.4 30.1

39.3 39.139.1

38.4 33.6 25.7 26.9

MEASUREMEASURE AHU Performance Summary,Level 1 –Level 8 (Tower Block)

- EXISTING UNIT

- NEW UNIT

- Capacity Above 31.0 TR

- Capacity Below 31.0 TR

Capacity Above 31.0 TR

Capacity Below 31.0 TR

= 33 Units

= 14 Units

CORE 1CORE 2(SOUTH)

CORE 3 CORE 5(NORTH)

CORE 4(WEST)

CORE 6(EAST)

LEGEND:

OSEC

OGC, OSEC, OPR, SPD & OED

SARD, SPRU PSOD

CWRD & RSOD

TD, RMU, OGA & CTL

BPMSD, BPHR, OIST & BPCD

DER & OAS

EDRC, COSO, OREI, PARD & OCO

SERD & EARD

Level 9

Level 8

Level 7

Level 6

Level 5

Level 4

Level 3

Level 2

Roof deck

Level 1

302826242220

Median

Mean

3029282726

Anderson-Darling Normality Test

Variance 8.954Skewness -1.51457Kurtosis 2.46665

N 14

Minimum 19.911

A-Squared

1st Quartile 26.115Median 28.3283rd Quartile 30.064

Maximum 30.537

95% Confidence I nterval for Mean

26.000

0.73

29.455

95% Confidence I nterval for Median

26.228 30.048

95% Confidence I nterval for StDev

2.169 4.821

P-Value 0.043

Mean 27.728StDev 2.992

95% Confidence I ntervals

Summary for Capacity(TR),Level 1-Level 8 Below 31 Tons

For Normal Data: P-Value >0.05Mean is approximately equal to median

For this Normality Test: P-value of 0.043 is < 0.05 Mean (27.728) not equal to Median (28.328)

MEASUREMEASURE Is Data NORMAL

Capacity(TR),act

Perc

ent

4035302520

99

95

90

80

70

605040

30

20

10

5

1

Mean

0.043

27.73StDev 2.992N 14AD 0.733

P-Value

Probability Plot of Capacity (TR) Level 1-Level 8 Below 31 TonsNormal - 95% CI

MEASUREMEASURE Normality Test

Data is not in a straight line pattern.

The normality test confirms that data is non normal

3632282420

LSL USLProcess Data

Sample N 14Shape 14.2118Scale 28.8787

LSL 31

Target *USL 38.6Sample Mean 27.7277

Overall CapabilityPp 0.51

PPL -0.29PPU 2.16Ppk -0.29

Observed PerformancePPM < LSL 1000000

PPM > USL 0PPM Total 1000000

Exp. Overall PerformancePPM < LSL 935324

PPM > USL 0PPM Total 935324

Process Capability of Capacity(TR),actCalculations Based on Weibull Distribution Model

MEASUREMEASURE Process Capability

Zlt = Ppk x 3 = -0.29 x 3 = -0.87Zst = Zlt + 1.5 = - 0.87 +1.5 = 0.63

% Defective of 27% or Equivalent PPM/DPMO = 274,523

Indiv

idual V

alu

e

1413121110987654321

30

25

20

_X=27.73

UCL=32.98

LCL=18.14

Movin

g R

ange

1413121110987654321

10

5

0

__MR=3.47

UCL=11.32

LCL=0

Observation

Valu

es

12963

30

25

20

3632282420

LSL USL

SpecificationsLSL 31.0USL 38.6

35302520

Overall

Specs

OverallShape 14.2118Scale 28.8787Pp 0.51Ppk -0.29

Process Capability Sixpack of Capacity(TR),actI Chart

Moving Range Chart

Last 14 Observations

Capability Histogram

Weibull Prob PlotAD: 0.547, P: 0.156

Capability Plot

MEASUREMEASURE Process Capability

Low Chilled Water Flow

Best Practices

Low Heat Transfer

Rate

ANALYZEANALYZE

Cooling Coil

Fan Motor

Spar

e pa

rts

Wea

r and

Tear

Pressure Drop

Pipi

ng

Particulate

Accumulation

Slime

Manpower and Supervision

Low Air Flow

Preventive Maintenance

Proc

edur

e

ISO Policy

Chilled Water Distribution

Pump

Balancin

g

Field devices

Motorized Valve

StrainerRoot

Causes of

Reduced Tonnage of AHUs

less than 31TR

Sche

dule

Duct P

ress

ure

Sens

or

Cooling Coil

Flat

tene

d

Fins

Cause and Effect Diagram

Wear

and Tear

Cooling Coil

Parameters UnitDesign

ConditionsActual

AverageDifference Effect

Cooling Capacity TR 38.64 27.73 10.91 reduce tonnage

Chilled Water Flow liters/sec 3.70 1.96 1.74 reduce water flow

Air Flow liters/sec 4,590.00 4,381.47 208.53 reduce air flow

Enthalpy Difference Btu/lbmass 10.50 8.15 2.35 low heat ransfer

Entering Air Temp., DB ºF 75.20 74.73 0.47

Leaving Air Temp.,DB ºF 48.00 56.74 -8.74

Supply Air Temp. ºF 53.60 59.74 -6.14

Pressure Drop across Cooling Coil in WC 1.10 0.76 0.34

Summary of AHU Parameters which contributes to the Root Causesof Reduced AHU tonnage below 31.0 TR

AHU Parameters, Level 1- Level 8ANALYZEANALYZE

The root causes of degradation of AHU performance was verified by one time measurement of AHU parameters and using engineering formulas to compare the current data with the manufacturers design data and coupled with the actual physical condition of the AHU components.

• Low Heat Transfer Rate at the cooling coil between the mix air and the chilled water by way of heat transfer at the cooling coil was verified by actual physical inspection of the cooling coil and taking pressure drop calculations on and off the coil.

• Low Chilled Water Flow observed at the AHU was attributed to the pressure drop at the piping components and verified by actual physical inspection. On the other hand low chilled water attributed to the central chilled water system was verified by measurement of chilled water flow at the risers.

• Low Air Flow was verified to have been cause by observed flattening of the cooling coil fins and the presence of particulate accumulation of the fins.

• Best Practices – Lack of supervision and training of AC technicians in measuring the AHU parameters before and after servicing and cleaning of AHU shows that improve performance have not been measured and verified to prove their effectiveness.

Analysis of Root CausesAnalysis of Root CausesANALYZEANALYZE

IMPROVEIMPROVE

Use ISO approved chemical agents.Evaluate the feasibility of replacing the coil.

BEST PRACTICES

PM procedures to include measure of AHU parameters before and after service. Training and supervision

LOW AIR FLOW

Calibration of duct static pressure sensor. Alternative sourcing of critical spare parts. Comb coil fins as necessary.

LOW CHILLED WATER FLOW

Chilled water balancing. Clean out pipes, strainers and coil at regular period based on measured parameter

PERFORMANCE CAPACITY OF AHUs

BELOW 31 TR

LOW HEAT TRANSFER

People or Groups

Level of Commitment

OAFA-FM /Process Owner

OAIS-PCSERVICE

PROVIDERADB STAFF (END USER)

Enthusiastic SupportX O X

Help it work X O

Compliant X

Hesitant

Indifferent

Uncooperative

Opposed

Hostile

X : Current level of commitment

O : Level of commitment needed

IMPROVEIMPROVE STAKEHOLDER ANALYSIS

Summary of Measured Parameters After Improvement SUPPLY TO

MAIN DUCT

Enthalpy

DifferenceWATER SIDE

Flow (lps)EAT DB

(ºF)% RH

LAT DB

(ºF)

Pressure Drop

(in. WC max)SAT DB (ºF) H2 - H1 Flow (lps)

Typical AHU 2.3 38.638 4590 75.2 56.7 48 1.1 - 10.5 3.7

S-1E 2.97 26.960 4032 73.5 63.20 54.60 0.90 61.7 8.42 1.00

S-1F 2.84 32.090 3834 74.7 73.00 55.10 0.90 60.6 10.54 2.71

S-2F 1.89 32.170 4063 73.7 62.00 53.50 0.58 54.5 9.97 3.05

S-3A 1.92 31.260 4753 73.7 64.70 56.80 0.80 60.4 8.28 2.29

S-3B 1.48 31.120 3970 74.8 64.60 54.00 0.73 62.2 9.87 1.77

S-3C 1.86 28.750 4859 73.7 65.40 57.00 1.00 63.5 7.45 1.90

S-3D 2.87 35.820 5113 75.7 58.10 53.20 0.90 55.2 8.82 1.90

S-3E 2.94 32.950 5078 74.4 66.10 56.00 0.88 59.7 8.17 1.10

S-5A 3.07 38.250 5140 73.8 65.30 54.70 0.74 47.0 9.37 2.00

S-5B 3.20 31.220 5878 72.9 64.50 55.90 0.90 58.5 6.69 1.20

S-5E 2.98 34.940 5333 74.4 65.40 55.00 0.90 58.1 8.25 1.46

S-6F 3.03 37.790 5240 72.8 55.20 50.90 1.00 55.0 9.08 2.42

S-7E 2.88 30.550 5366 74.3 68.00 56.80 0.80 62.1 7.17 1.05

S-8A 2.92 30.820 4659 74.8 56.80 53.10 0.94 53.7 8.33 4.50

Equipment

Face

Velocity

(m/s)

Capacity

(TR)

AIR SIDE ACROSS COOLING COIL

AHU PerformanceIMPROVEIMPROVE

NOAS-1 NOAS-2 NOAS-3 NOAS-4 NOAS-5 NOAS-6

S-9A(42.3) S-9B(42.3) S-9C(42.3) S-9D(42.3) S-9E(42.3) S-9F(42.3)

S-8A(40.9) S-8B(40.9) S-8C(40.9) S-8D(40.9) S-8E(40.9) S-8F(40.9)

S-7A(38.6) S-7B(38.6) S-7C(38.6) S-7D(38.6) S-7E(38.6) S-7F(38.6)

S-6A(38.6) S-6B(38.6) S-6C(38.6) S-6D(38.6) S-6E(38.6) S-6F(38.6)

S-5A(38.6) S-5B(38.6) S-5C(38.6) S-5D(38.6) S-5E(38.6) S-5F(38.6)

S-4A(38.6) S-4B(38.6) S-4C(38.6) S-4D(38.6) S-4E(38.6) S-4F(38.6)

OAS7 OAS8 OAS9 OAS10 S-3A(38.6) S-3B(38.6) S-3C(38.6) S-3D(38.6) S-3E(38.6) S-3F(38.6)

S17(102.9) S18(96.0) S19(29.5) S20(48.6) S21 S-10B(63.4) S-10A(63.4) S-2A(38.6) S-2B(38.6) S-2C(38.6) S-2D(38.6) S-2E(38.6) S-2F(38.6)

S13(68.1) S14(68.1) S15(62.3) S16(62.3) S-10D(81.8) S-10C(81.8) S-1A(32.5) S-1B(32.5) S-1C(32.5) S-1D(32.5) S-1E(32.5) S-1F(32.5)

BPUMP1 BPUMP2 BPUMP3 SB1(90.1) SB2(33.0) SB3(90.1)

BPUMP4 BPUMP5 BPUMP6

ASIAN DEVELOPMENT BANKAHU SYSTEM

S11(80.2) S12(114.6)

Segment BSegment C

EAST CENTRAL

WEST

EAST WEST

EAST WEST

Segment A

30.82

30.55

37.79

31.26

31.12

28.75

35.82

32.95

BASEMENT 1 FANPOWERS

38.25

34.94

32.17

26.96

32.09

31.22

IMPROVEIMPROVE

CORE 1CORE 2(SOUTH)

CORE 3 CORE 5(NORTH)

CORE 4(WEST)

CORE 6(EAST)

- EXISTING UNIT

- NEW UNIT

- Capacity Above 31.0 TR

- Capacity Below 31.0 TR

Capacity Above 31.0 TR

Capacity Below 31.0 TR

= 10 Units

= 4 Units

LEGEND:

Level 9

Level 8

Level 7

Level 6

Level 5

Level 4

Level 3

Level 2

Roof deck

Level 1

AHU Performance SummaryAfter Improvement

Parameters UnitDesign

ConditionsBefore After Difference

Cooling Capacity TR 38.64 27.73 32.48 4.75

Chilled Water Flow liters/sec 3.70 1.96 2.12 0.16

Air Flow liters/sec 4,590.00 4,381.47 4,808.00 426.53

Enthalpy Difference Btu/lbmass 10.50 8.15 8.60 0.45

Entering Air Temp., DB ºF 75.20 74.73 74.08 -0.65

Leaving Air Temp.,DB ºF 48.00 56.74 54.76 -1.98

Supply Air Temp. ºF 53.60 59.74 58.00 -1.74

Pressure Drop across Cooling Coil in WC 1.10 0.76 0.85 0.09

Summary of Measured Parameters Before and After Improvement

AHU Parameters, Level 1- Level 8IMPROVEIMPROVE

38363432302826

Median

Mean

353433323130

Anderson-Darling Normality Test

Variance 10.373

Skewness 0.420714Kurtosis -0.187581N 14

Minimum 26.963

A-Squared

1st Quartile 30.754

Median 31.6723rd Quartile 35.159Maximum 38.247

95% Confidence I nterval for Mean

30.618

0.43

34.337

95% Confidence I nterval for Median

30.808 34.985

95% Confidence I nterval for StDev

2.335 5.189

P-Value 0.268

Mean 32.477StDev 3.221

95% Confidence I ntervals

Summary for AHU Capacities (TR),Improve

IMPROVEIMPROVEIs data NORMAL

For Normal Data: P-Value >0.05Mean is approximately equal to median

For this Normality Test: P-value of 0.268 is > 0.05 Mean (32.45)is approximately equal to Median (31.67)

AHU Capacities (TR),Improve

Perc

ent

454035302520

99

95

90

80

70

605040

30

20

10

5

1

Mean

0.268

32.48StDev 3.221N 14AD 0.428P-Value

Probability Plot of AHU Capacities (TR),ImproveNormal - 95% CI

Normality TestIMPROVEIMPROVE

Data points are within the confidence interval

The normality test confirms that data is normal

4038363432302826

LSL USLProcess Data

Sample N 14

StDev(Within) 3.06651

StDev(Overall) 3.28324

LSL 31

Target *USL 38.6

Sample Mean 32.4772

Potential (Within) Capability

Overall Capability

Pp 0.39

PPL 0.15

PPU 0.62Ppk 0.15

Cpm

Cp

*

0.41

CPL 0.16CPU 0.67

Cpk 0.16

Observed Performance

PPM < LSL 285714.29

PPM > USL 0.00PPM Total 285714.29

Exp. Within Performance

PPM < LSL 315002.98

PPM > USL 22930.75PPM Total 337933.73

Exp. Overall Performance

PPM < LSL 326384.16

PPM > USL 31100.25PPM Total 357484.41

WithinOverall

Process Capability of AHU Capacities (TR),Improve

Zlt = Ppk x 3 = 0.15x 3 = 0.45Zst = Zlt + 1.5 = 0.45 +1.5 = 1.95

New Process Sigma is equivalent to 2.9% Defective or 28 or 28,716 DPMO

IMPROVEIMPROVE Process Capability

Baseline Process Sigma =0.63. Equivalent to Defective of 27% or PPM/DPMO = 274,523

AHU Capacities (TR),Improve

Fre

qu

en

cy

38363432302826

6

5

4

3

2

1

0

-1

X_

Ho

Histogram of AHU Capacities (TR),Improve(with Ho and 95% t-confidence interval for the mean)

One-Sample T: AHU Capacities (TR), Improve

Test of mu = 31 vs not = 31

Variable N Mean StDev SE Mean 95% CI T PAHU Capacities ( 14 32.4772 3.2208 0.8608 (30.6176, 34.3368) 1.72 0.110

Ho: mu1 = 31 TRNull Hypothesis: There is no difference between improved performance and the target mean

Ha: mu1 is not = 31TRAlternative Hypothesis: There is a difference between the improved performance and the target mean

Since P (0.110) > 0.05 (0.000), we will reject Ha and accept HoTherefore, there is no difference between the improve performance and the target mean

CONTROLCONTROL 1 Sample t-test

CONTROLCONTROL OLD AHU UNITS

Vane axial fans provide variable air volume by utilizing controllable pitch blades, the most efficient at that time of installation.

1.

Restricted access for cooling coil clean out

2.

Very durable and rugged construction makes these units very reliable

3.

4. ASHRAE equipment handbook estimates the mean economic life of 20 years for the cooling coils.

Problems on sourcing some maintenance parts (original or replacement increases cost of maintenance

5.

FEATURES AND CURRENT OPERATING CONDITIONS

CONTROLCONTROL PROPOSED AHU REPLACEMENT

Newly Installed DAIKIN AHU Units Proven to be Effective With the Following

Features:Highly efficient variable speed drives saves 35% of operating cost with an estimated payback of 3 years for these drives.

1.

Compact size for ease of installation and maintenance.

2.

Advanced performance via digital microprocessor control and serial communications.

3.

Latest trends in AHU technology such as provision of ultraviolet germicidal irradiation (UVGI) for cooling coil disinfection can be explored which makes good energy and environmental example.

4.

CONTROLCONTROLControl Measureand Guidelines

Service Provider ADB Staff1. Implementation of guidelines for the efficient AHU operation.

To be coordinated with ISO group. Document change to be completed on September 30, 2008. Incorporate job plan in CMMS.

Service provider supervisor, AC technicians

Duty Senior Engineering Officers/Asst. Engineers

On-going,

2. Determine optimum cleaning schedule using cleaning chemicals.

Computerized Maintenance Management System (CMMS) report, I-MR Chart

Service provider supervisor, AC technicians

E.Nacpil, A. Castro On- going

3. Training and orientation of ADB engineers and Service provider on the new Standard operating procedures on AHU servicing.

This six sigma control measures to be circulated in O and M group. Service Provider

Management -CPMIE Nacpil, FM Shift Engineers On -going

4. Cleaning and servicing of the rest of the 44 old air handling units.

Schedule as outline in the control phase Service Provider Supervisor, AC technicians

Duty SEO /Assistant Engineers

July 15 onwards

5. Ensure availability of spare parts for the continuous operation and efficient operation of air handling units.

Critical items inventory in Oracle SystemService Provider Supervisor,

Maintenance PlannerADB Assistant Mechanical

EngineersOn-going

6. Monthly review of maintenance of the AHU

7. Ensure AHU operating parameters are within the target range.

I-MR chart, Process Control Plan Service provider supervisor, AC technicians

Duty Senior Engineering Officers,Assistant Engineers

On-going

8. Conduct an in depth analysis of the maintenance item to detect area for continuous improvement.

Computerized Maintenance Management System (CMMS) report Service provider supervisor E.Nacpil, A. Castro On -going

9. Program for the replace air handling unit project.

Computerized Maintenance Management System (CMMS) report E Nacpil, A. Castro

3-to 5 year program

On -going

Action Plan Reference Status

i. defects rectification of AHU components

Responsible

Computerized Maintenance Management System (CMMS) report. Service Provider

Management-CPMI

G. Villamor for Instrumentation,Assistant

Engineers for mechanical and electrical systems

CONTROLCONTROLProcess Control Plan

Process Step

Reference Document

Control Parameter

Specification, as found

Tolerance from

spefications

Inspection Frequency

Sample Size

Monitoring Method

Responsible

Heat transfer Improve PhaseChange in enthalpy

8.60 Btu/lb mass Below 10% every two weeks 100% I-MR chart ADB/CPMI Engineers

Heat transfer Improve Phase Supply air flow4,808 liters per

secondBelow 10% every two weeks 100% I-MR chart ADB/CPMI Engineers

Heat transfer Improve Phase Chilled water flow2.12 liters per

secondBelow 10% every two weeks 100% I-MR chart ADB/CPMI Engineers

Process Control Plan

Monitoring of AHU parameters shall be done every two (2) weeks, beginning at completion of improve phase and taking measurements of parameters thereof to determine the optimum schedule for chemical cleaning which could be quarterly or every six months . However the monthly cleaning using water and detergent shall continue in accordance with the schedule in CMMS.

CONTROLCONTROLControl Plan Root Causes

Service provider ADB staff

Low chilled water flowReduced capacity in tons of

refrigeration (TR)Clean out strainers, motorized valve and piping components

Supervisor, AC technicians

Duty SEO’s and AE’s

On –going

Low air flow Reduced capacity Comb coil fins as necessarySupervisor, AC

techniciansDuty SEO’s and

AE’sOn-going

Chemical cleaning of cooling coilsSupervisor, AC


AE’sOn-going

Servicing of AHU fan motor components such as duct static pressure sensor and replacement of parts

PID and CPMI technicians


On-going

Low heat transfer Reduced capacity Chemical cleaning of cooling coilsSupervisor, AC


AE’sOn-going

Best practices on O&M Reduced capacity

Implementation of preventive maintenance of AHU in accordance with this Six Sigma project on chemical cleaning and taking measurements of key metrics

Supervisor, AC technicians


On-going

Replace cooling coil base on cost and benefit analysis

E Nacpil Next 3 - 5 years

ImplementationResponsible Person

Cause Effect Action to be taken

Observation

Indiv

idual V

alu

e

1413121110987654321

40

35

30

25

20

_X=32.48

UCL=42.14

LCL=22.82

Observation

Movin

g R

ange

1413121110987654321

12

9

6

3

0

__MR=3.63

UCL=11.87

LCL=0

AHU CAPACITY AFTER IMPROVE PHASE

CONTROLCONTROL I –MR CHART, AHU CAPACITY

Observation

Indiv

idual V

alu

e

1413121110987654321

10

9

8

7

6

_X=7.93

UCL=9.857

LCL=6.003

Observation

Movin

g R

ange

1413121110987654321

2.4

1.8

1.2

0.6

0.0

__MR=0.725

UCL=2.368

LCL=0

kW RATING AFTER IMPROVE PHASE

CONTROLCONTROL I –MR CHART,kW RATING

Observation

Indiv

idual V

alu

e

1413121110987654321

6000

5500

5000

4500

4000

_X=4808

UCL=5902

LCL=3715

Observation

Movin

g R

ange

1413121110987654321

1500

1000

500

0

__MR=411

UCL=1343

LCL=0

AIR FLOW(Lps) AFTER IMPROVE PHASE

Observation

Indiv

idual V

alu

e

1413121110987654321

4.8

3.6

2.4

1.2

0.0

_X=2.119

UCL=4.893

LCL=-0.655

Observation

Movin

g R

ange

1413121110987654321

3

2

1

0

__MR=1.043

UCL=3.408

LCL=0

CHILLED WATER FLOW AFTER IMPROVE PHASE

CONTROLCONTROL I –MR CHART,CHW WATER FLOW

Observation

Indiv

idual V

alu

e

1413121110987654321

6000

5500

5000

4500

4000

_X=4808

UCL=5902

LCL=3715

Observation

Movin

g R

ange

1413121110987654321

1500

1000

500

0

__MR=411

UCL=1343

LCL=0

AIR FLOW AFTER IMPROVE PHASE

CONTROLCONTROL I –MR CHART, AIR FLOW

Observation

Indiv

idual V

alu

e

1413121110987654321

12

10

8

6

4

_X=8.601

UCL=12.514

LCL=4.687

Observation

Movin

g R

ange

1413121110987654321

4.8

3.6

2.4

1.2

0.0

__MR=1.472

UCL=4.808

LCL=0

CHANGE IN ENTHALPY AFTER IMPROVE PHASE

I –MR CHART,ENTHALPY CONTROLCONTROL

Timeline for Project Commissioning, Project Closeout Meetings and Validate Gate Review

Gate Review

StopStop

3 months to improve the rest of olderAir Handling Units

12 months

ongoing

ValidateControl$

Sustain (optional)

Final Results Review

Meeting*

Transfer to Process Owner

(Commissioning Meeting*)

Transfer Review

Meeting*

** Project Closeout Meeting

(Team members)

* Meetings that are part of the Project Commissioning Process** Meeting that is the official end of the Project

CONTROLCONTROL

“annual improvement”

HARD AND SOFT SAVINGS

I. Hard Savings

Improve performance of the air handling units resulted in savings of 3.23% in power consumption which translates into annual energy cost savings of USD 7,010.00

Recover loss capacity of around 17.10 % due to improve performance resulted in a recovery of 66.36 tons of refrigeration (TR) for the 14 units and thereby improving

the overall chilled water plant efficiency. This recovery of additional 66.36 TR translates to an additional annual energy cost savings of USD 1,738.90.

II. Soft Savings Improved documentation of current operating condition of air handling unit can

be used for future building retrofit or AHU replacement project.

Energy and Resource Conservation initiatives without major costs proven to be effective.

Knowledge and techniques gained can be replicated to improve the operating performance of the components of the air conditioning system such as cooling towers and refrigeration equipment.

Project BenefitsCONTROLCONTROL

Summary of AHU Power Consumption Savings After Improvement

Cost SavingsCONTROLCONTROL

KW

(Before)

KW

(After)Difference %

Annual

KW-HR Savings (14 sample units)

Annual

KW-HR Saving

(including all

old units)

Rate

Php/(KW-HR)

Total Annual Cost

Savings

Php 312,302

U$ 7,010

10,661 49,259 6.348.04 7.78 0.26 3.23

Reference:

1 US Dollar (USD) = 44.55 Phil. Peso (Php), June 2008

kW-HR Savings in Reduced Chilled Water at the Secondary Chilled Water Pump

Cost SavingsCONTROLCONTROL

Peak HP

(Before)

Hp Rating

(After)Difference %

Annual

KW-HR Savings (14 sample units)

Rate

Php/(KW-HR)

Total Annual Cost

Savings

Php 77,470

U$ 1,739

12,219 6.3422.7 18.2 4.5 19.8

Reference:

1 US Dollar (USD) = 44.55 Phil. Peso (Php), June 2008

• The data driven problem solving approach of Six Sigma enable this complex engineering problem to succeed.

• Teamwork and the proper selection of team members with specific functional roles is crucial so that target completion date of each phase of the project can be met following the DMAIC methodology.

• Using the Minitab as a tool to analyze data, we were able to document the current operating performance of the air handling units in addition to the standard engineering calculations used to measure performance.

• Continuous improvement in AHU performance can be sustained by strategically involving the process owners (AC technicians) in data gathering and analysis and showing them how Six Sigma works to uncover inefficiencies.

Lessons LearnedCONTROLCONTROL

Thank you

OAFA-FM

1. AHU PERFORMANCE VERIFICATION SAMPLE CALCULATION

2. ESTIMATE kW-HR SAVINGS IN AHU POWER CONSUMPTION OF SAMPLE UNITS

3. ESTIMATE kW-HR SAVINGS IN AHU POWER CONSUMPTION OF OLD UNITS

4. ESTIMATE kW-HR SAVINGS DUE TO REDUCED CHILLED WATER FLOW

5. COMPARISON KW RATING BETWEEN NEW AND OLD UNITS

6. HEAT TRANSFER PROCESS SHOWN THROUGH PSYCHROMETRIC CHART

7. CHART OF WATER FLOW VERSUS HEAT TRANSFER RATE

8. PARETO CHART OF DEFECTS FROM 1992 TO 2008

9. MAINTENANCE PARTS (PHOTO)

ATTACHMENTSATTACHMENTS

MEASUREMEASUREPerformance Verification

AHU: S-3A Date:Fanroom: Time:

1 Mix air flow

2.8 1.7 1.7 1.2 1.7 1.6 1.9 1.3 Vel. Ave = 1.75313 m/s2.4 2.1 1.9 1.3 2.2 1.5 1.8 1.9 MA flow = Vel. Ave x Area2.1 1.8 1.8 2 2.4 1.3 1.4 1.8 = 5.78531 m3/sec2.1 1.5 1.3 1.5 1.7 1.6 1.2 1.6 MA flow = 5785.31 lps

2 Flow after Cooling Coil2000mm

2.2 2.1 2.8 1.9 2.4 2.2 Vel. Ave = 2.44583 m/s2.4 2 2.5 2.1 3 2.7 flow off coil = Vel. Ave x Area2.1 2.2 2.7 1.8 2.7 3.1 = 4.89167 m3/sec2 2.4 2.9 2.4 3.1 3 flow off coil = 4891.67 lps

3 OA flow to Fanroom290mm

5.8 8.9 9.7 Vel. Ave = 8.6 m/s6.3 10.4 9.2 OA flow = Vel. Ave x Area7.8 10.4 8.9 = 0.6235 m3/sec

OA flow = 623.5 lps4 RA to Fanroom

3850mm1.9 0.7 1.2 1.4 1.4 1.2 1.6 Vel. Ave = 1.37143 m/s1.9 0.4 1.6 0.6 1.5 1.1 1.5 RA flow = Vel. Ave x Area1.6 0.9 1.3 0.7 1.7 1.6 1.8 = 4.752 m3/sec0.8 1.4 1.8 1.4 1.9 2 1.5 RA flow = 4752 lps

5 CHWS temp. 8.5 ºC = 47.3 ºF6 CHWR temp. 18 ºC = 64.4 ºF7 Off Coil temp. 12.67 ºC = 54.8 ºF9 Off Coil %RH = 90.5 % h1 = 22.14 Btu/hr

10 at Fan temp. 12 ºC = 53.6 ºF12 at Fan %RH = 90.7 %13 SA temp. 12.78 ºC = 55 ºF15 SA %RH = 88.6 %16 RA temp. 23.33 ºC = 74 ºF18 RA %RH = 63.4 %19 OA temp. 23.89 ºC = 75 ºF 28 CHW flow rate21 OA %RH = 91.3 % = 2.8728 lps22 MA temp. 23.33 ºC = 74 ºF 29 CHW velocity24 MA %RH = 61.9 % h2 = 29.95 Btu/hr = 0 m/sec25 Differential Pressure across filter: 0.17 " wc26 Differential Pressure across coil: 1.1 " wc

27 Coil Cooling Load = 9.53 x flow off coil x (h2 - h1)= 9.53 x x 7.81== 33.34 TR

5375.5400,094.70

1000

mm

250m

m

900m

m

14-Jul-0813:40 - 14:57

3000mm

1100

mm

MEASURE MEASURE Estimate KW-HR Savings Of 14 Sample Units

Savings = (8.04 kw – 7.78 kw) x 14 units x 2929 hours/year = 10,661 kw-hrs

Item

NoLocation

kW

reading

before

kW

reading

after

Capacity

before

(TR)

Capacity

after

(TR)

Running hours

(annual)Remarks

Segment ALevel 8

1 S-8A 9.64 9.6 26.26 30.82 2,795Level 7

2 S-7E 7.84 7.69 30.33 30.56 2,730Level 6

3 S-6F 8.11 8.05 29.96 37.79 3,250Level 5

4 S-5A 7.97 7.97 30.54 38.25 2,7305 S-5B 7.76 7.59 24.13 31.22 3,5106 S-5E 7.9 7.71 28.17 34.94 2,730

Level 37 S-3A 7.87 7.73 30.04 31.26 2,7308 S-3B 8.09 8.05 28.49 31.12 3,7709 S-3C 7.89 7.41 19.91 28.75 2,47010 S-3D 7.41 7.15 29.62 35.82 3,25011 S-3E 8.21 8.11 28.08 32.95 2,730

Level 212 S-2F 7.5 6.67 30.12 32.17 2,470

Level 113 S-1E 8.41 7.4 25.69 26.96 2,73014 S-1F 7.92 7.81 26.86 32.09 3,120

8.04 7.78 27.73 32.47 2,929Average

Average decrease in kw capacity at full load = (8.04 kw – 7.78 kw) / 8.04 x 100% = 3.23%

Savings in Tons of Refrigeration (TR) = (32.47 TR – 27.73 TR) x 14 units = 66.36 TR

Average increase in Tons of Refrigeration (TR) at full load = (32.47 TR – 27.73 TR) / 27.73 x 100% = 17.1%

Item No Location kW design Design

Capacity (TR)

Running hours

(annual)Status

Segment ALevel 9

1 S-9A 11.25 42.3 2,8812 S-9B 11.25 42.3 3,1403 S-9C 11.25 42.3 2,8814 S-9E 11.25 42.3 2,881

Level 8

5 S-8B 7.5 38.6 3,8356 S-8C 7.5 38.6 2,5357 S-8D 7.5 38.6 3,8358 S-8E 7.5 38.6 2,5359 S-8F 7.5 38.6 3,315

Level 7

10 S-7A 7.5 38.6 2,73011 S-7B 7.5 38.6 4,23812 S-7C 7.5 38.6 2,47013 S-7D 7.5 38.6 3,51014 S-7F 7.5 38.6 3,640

Level 6

15 S-6A 7.5 38.6 2,73016 S-6B 7.5 38.6 3,77017 S-6C 7.5 38.6 2,47018 S-6D 7.5 38.6 3,38019 S-6E 7.5 38.6 2,730

Level 5

20 S-5C 7.5 38.6 2,47021 S-5D 7.5 38.6 3,510

22 S-5F 7.5 38.6 3,510

Item No Location kW design Design

Capacity (TR)

Running hours

(annual)Status

Segment ALevel 4

23 S-4A 7.5 38.6 2,73024 S-4B 7.5 38.6 3,64025 S-4C 7.5 38.6 2,73026 S-4D 7.5 38.6 3,51027 S-4E 7.5 38.6 3,19828 S-4F 7.5 38.6 3,250

Level 3

29 S-3F 7.5 38.6 3,380Level 2

30 S-2A 7.5 38.6 2,73031 S-2C 7.5 38.6 2,73032 S-2D 7.5 38.6 3,445

Level 1

33 S-1D 7.5 32.5 3,250Basement 1

34 S-B2 5.6 33 3,796Segment B

35 S-10A 11.25 63.4 2,75636 S-10B 11.25 63.4 1,04037 S-10C 11.25 81.8 1,326

Segment C38 S-13 18.75 68.1 13039 S-14 18.75 68.1 3,23740 S-15 18.75 62.3 2,99041 S-16 18.75 18.75 2,730

42 S-17 18.75 102.9 1,126

43 S-19 11.25 29.5 447

44 S-20 15 48.6 1,482

9.59 43.69 2,832Average

Ave. decrease in KW capacity at full load based on 14 samples = 3.23%

MEASUREMEASURE Estimate KW-HR Savings Of 44 Old Units

Estimated savings = .0323 x 9.59 kw x 44 units x 2832 hr/yr = 38,598 kw-hrs

MEASUREMEASURE

ESTIMATE kW-HR SAVINGS DUE TO REDUCED CHILLED WATER FLOW,14 Sample Units

1 capacity (TR) of typical ahu from level 2 to level 8 38.6 tons of refrigeration

2 chilled water flow at full load of ahu from level 2 to level 8 3.7 liters / second

3 average running hours per year of typcial ahu 3000 hours/ year

4 tons recovered from the sample 14 units 66.36tons (six sigma project

improve phase)

5 equivalent chilled water flow 6.36 liters/ second

6

reduce kw rating of new secondary chilled water booster pump at

Segment A using the actual pump curve at the time of testing and

commissioning

18.2 hp

7peak kw rating of new secondary chilled water booster pump at Segment A

using the actual pump curve at the time of testing and commissioning22.7 hp

8 reduction in kw rating of new secondary chilled water pump at Segment A 4.5 hp

9the savings in reduced power required by the secondary chilled water

pump due to reduced chilled water flow63,850.14 Php

10 equivalent savings in USD 1,433.22 USD

COMPUTATION OF SAVINGS FROM REDUCED CHILLED WATER FLOW

WHEREBY THE PUMP GENERATES HEAT BY CHURNING THE

WATER,WHICH MUST IN TURN BE COOLED BY THE CHILLER

1 savings in heat input to the chilled water 13,619.91 Php

2 equivalent savings in USD 305.72 USD

TOTAL PUMP SAVINGS 77,470.05 Php

TOTAL PUMP SAVINGS 1,738.95 USD

COMPUTATION OF SAVINGS ON ELECTRICAL INPUT FROM REDUCED CHILLED WATER AT THE

SECONDARY CHILLED WATER PUMP FLOW OF THE 14 SAMPLE AHU UNITS AT SEGMENT A

Estimate KW-HR Savings Reduced CHW Flow

MEASUREMEASURE

TEST RUN OF AHU BEFORE AND AFTER REPLACEMENT WITH NEW UNITS EQUIPPED

WITH VSD

Item No

Location kW DesignCapacity

(TR)

Running hours

(annual)Status

Segment A

Level 9

1 S-9D 11.25 42.3 3,271 new

2 S-9F 11.25 42.3 3,401 new

Level 2

3 S-2B 7.5 38.6 6,825 new

4 S-2E 7.5 38.6 6,669 new

Level 1

5 S-1A 7.5 32.5 2,860 new

6 S-1B 7.5 32.5 3,510 new

7 S-1C 7.5 32.5 2,470 new

BASEMENT 1

8 S-B1 18.5 90.1 8,736 new

9 S-B3 18.5 90.1 2,730 new

SEGMENT B

10 S-10D 11.25 81.8 390 new

SEGMENT C

11 S-11 22.5 80.2 8,736 new

12 S-12 18.75 114.6 3,198 new

13 S-18 22.5 96 2,100 new

14 S-21 3.7 15 3,523 new

Item No

Location kW DesignCapacity

(TR)

Running hours

(annual)Status

NOAS SEG A

15 NOAS-1 18.5 68.2 1,170 new

16 NOAS-2 18.5 68.2 1,040 new

17 NOAS-3 18.5 68.2 2,210 new

18 NOAS-4 18.5 68.2 2,210 new

19 NOAS-5 18.5 68.2 1,040 new

20 NOAS-6 18.5 68.2 1,170 new

NOAS SEG C

21 NOAS-7 18.5 68.2 1,430 new

22 NOAS-8 18.5 68.2 1,430 new

23 NOAS-9 18.5 68.2 1,430 new

24 NOAS-10 18.5 68.2 1,430 new

360.7 1509.1 72,979

25.76 107.79 5,213

Total

Average

Item

NoLocation

kW

Old

kW

New

%

difference

Running

hours

(annual)

Date of test

Segment A

1 S-2E 12.15 7.88 35% 6,669 03/ 10/ 2007 and 16/ 10/ 2007

BASEMENT 1

2 S-B3 3.79 2.14 43% 2,730 8/ 8/ 2007 and 21/ 8/ 2007

SEGMENT C

3 S-12 16.00 13.38 16.40% 3,198 18/ 10/ 2007 and 02/ 11/ 2007

KW OF OLD AND NEW UNITSCOMPARISON

Entha

lpy,

Btu

/lb(a

)

Hu

mid

ity r

atio

, lb

/lb(a

)

Pressure: 14.6959 psi

Dry bulb temperature, deg F40 50 60 70 80 90 100

0.010

0.020

20%

40%

60%

80%

10

20

30

40

50

30

40

50

50

60

70

80

OA

MA

SA

Off Coil

At Fan

RA

Measure Measure

Psychometric Chart of AHU S-6E showing the heat

transfer process through the coil

Heat Transfer Process

0

70

90

100

40

80

90 100

50

60

30

20

10

50 60 70 8010 20 30 40

ANALYZEANALYZE

Correlation Between Water Flow and Heat Transfer Rates for a

Typical Cooling System Terminal Unit

% Design Flow Rate

% D

esig

n H

eat

Tra

nsfe

r

Source: ASHRAE Handbook

Count

Perc

ent

defects from 1992 to 2008

CountPercent 41.0 12.8 11.0 9.3 9.0 6.6 5.2 5.2Cum %

119

41.0 53.8 64.8 74.1 83.1 89.7 94.8100.0

37 32 27 26 19 15 15

Fan Mot

or

Duct

wor

k Acc

esories

Cooling

Coils

Air Co

mpres

sor

Piping

Rotary U

nion

Diaphrag

m

Pitch

Blad

e Ca

ble

300

250

200

150

100

50

0

100

80

60

40

20

0

Pareto Chart of defects from 1992 to 2008

ANALYZEANALYZE Pareto Chart of Defects on Maintenance Parts

ANALYZEANALYZE

Fan motor assembly which has a record for the most number of defects in the Air Handling Unit such as pitch cable, rotary

union, diaphragm and the air compressor.

Maintenance spare parts of pitch blade such as the diaphragm, rotary union

and pitch cable becomes critical every now and then because these are no longer manufactured by the original

equipment manufacturer.

Pitch blade of fan motor available as saved from scrap of dismantled units last 2007. There are 2 sets of reconditioned spare parts for 4 units for level 9 and 5 sets for the rest of the other 54 units.

Maintenance Parts

define

Documents