hvac talk - · pdf filesuper-e electric motor 5. ... improperly mounted ultrasonic flow meter...
TRANSCRIPT
Date
By Lee Eng Lock
HVAC Talk
Insert Footer2
• Chong Qing, • Hang Zhou, • Shen Zhen
in China
Psychometric Chart for Weather Data from:
Insert Footer3
Location Map of the 3 cities
Insert Footer4
Chong Qing Weather Data
2004 - 2006
2004 2006
Insert Footer5
Hang Zhou Weather Data
2004 - 2006
2004 2006
Insert Footer6
Shen Zhen Weather Data
2004 - 2006
2004 2006
Insert Footer7
AHU ENERGY RETROFIT
New AHU Design Criteria
1. Low air velocity across filter and cooling coil2. Air pre-cool by 15 degC chilled water3. High efficiency Airfoil direct driven fan4. Super-E electric motor5. Variable speed drive6. Digital temperature Control7. Non flammable AHU panel8. High resistance of coil to corrosion (powder coating)
CASE STUDY 1. ST Microelectronics CASE STUDY 1. ST Microelectronics PtePte LtdLtd
Insert Footer8
AHU ENERGY RETROFIT
New AHU Plan View
CASE STUDY 1. ST Microelectronics CASE STUDY 1. ST Microelectronics PtePte LtdLtd
Insert Footer9
AHU ENERGY RETROFIT
New AHU Section
CASE STUDY 1. ST Microelectronics CASE STUDY 1. ST Microelectronics PtePte LtdLtd
Insert Footer10
AHU ENERGY RETROFIT
CASE STUDY 1. ST Microelectronics CASE STUDY 1. ST Microelectronics PtePte LtdLtd
Executive SummaryOLD and NEW AHU PERFORMANCE
# AHU Parameter (100% fresh air): Unit OLD AHU NEW AHU
1 Total cooling capacity Ton refrigerant 340 354
2 Chilled water supply temperature Degree C 6
15-pre-cool,
6-final cooling
3 Chilled water temperature rise Degree C 5.5 11
4 Fan power consumption KW 35 7
5 Chiller power consumption KW 212 170
6 AHU efficiency KW/Ton 0.1 0.02
SAVINGS
# Savings (for 2 units): kW % $Sin/Year
1 Fan power consumption 56 80 72,800
2 Chiller power consumption 84 20 109,200
3 Total 140 182,000
Payback period of investments 1.9 years
Insert Footer11
Existing Ultrasonic Flow Meter
Insert Footer12
Newly Installed Ultrasonic Flow Meter
Header MF?
Insert Footer13
Magnetic flow meter on condenser flow
Insert Footer14
Magnetic flow meter on chilled water flow
Insert Footer15
New USFOld USF on the vertical pipe
Three MFs on chilled side
Three MFs on condenser side
Insert Footer16
UF installation
Insert Footer17
MF installation
From OMEGA Engineering
Insert Footer18
Flow measure comparison
Flow measurement comparison (GPM) 18Nov08
1000.00
1100.00
1200.00
1300.00
1400.00
1500.00
1600.00
1700.00
1800.00
1900.00
2000.00
7:0
0
8:0
0
9:0
0
10:0
0
11:0
0
12:0
0
13:0
0
14:0
0
15:0
0
16:0
0
17:0
0
18:0
0
time
gpm USFnew(header)
USFold(header)
MF existing(header)
1) Correctly mounted ultrasonic flow meter reading matches the existing magnetic flow reading
2) Improperly mounted ultrasonic flow meter reading is 15% lower than correctly mounted ultrasonic flow meter and the existing magnetic flow meter
Insert Footer19
Cooling load comparison
Cooling load comparison (tons) 18Nov08
400
500
600
700
800
900
1000
1100
7:00 8:00 9:00 10:00 11:00 12:00 13:00 14:00 15:00 16:00 17:00 18:00
Cooling load (USF new)
Cooling load (USF old)
Cooling load (MF existing)
1) Equipment switched on at 7.30am, switched off at 6:pm
2) There is a cooling load spike in the early morning due to the heat accumulation during the night.
Insert Footer20
Efficiency comparison (kw/ton) (18Nov08)
0.60
0.70
0.80
0.90
1.00
1.10
1.20
7:00
7:30
8:00
8:30
9:00
9:30
10:0
010
:30
11:0
011
:30
12:0
012
:30
13:0
013
:30
14:0
014
:30
15:0
015
:30
16:0
016
:30
17:0
017
:30
18:0
018
:30
Efficiency (USF new)
Efficiency (USF old)
Efficiency (MF existing)
Efficiency comparison
Insert Footer21
Efficiency comparison
Efficiency comparison (kw/ton) (18Nov08)
0.00
0.20
0.40
0.60
0.80
1.00
1.20
7:00
7:30
8:00
8:30
9:00
9:30
10:0
010
:30
11:0
011
:30
12:0
012
:30
13:0
013
:30
14:0
014
:30
15:0
015
:30
16:0
016
:30
17:0
017
:30
18:0
018
:30
Efficiency (USF new)
Efficiency (USF old)
Efficiency (MF existing)
Insert Footer22
Spot measurement
Chill plant power: 421.8 kw
Chiller plant flow rate: 2441gpm
Chiller Chw temp in: 52.34F (11.3 C)
Chiller Chw temp out: 46.22F(7.9C)
The resultant plant efficiency: 0.6776 kw/ton
The measurement time is around 9:30am to 10:30amComparing with the logging graph, the spot measured efficiency is lower than logging data which is 0.71-0.88kw/ton based on UF new and MF existing flow measurement, but acceptable
Insert Footer23
• The sampling rate is 1 minute
• The readings from correctly mounted ultrasonic flow meter matches well those from magnetic flow meter mounted on the header
• Due to the improper mounting of the old ultrasonic ( air accumulation), the readings from old UF is 15% lower than new correctly mounted UF, which causes the higher efficiency deviation
• During the equipment switching on and off period, unsteady operating condition affects the flow meter reading greatly
• Chiller plant average efficiency from 8:am to 6pm on Nov.18, 2008 is 0.79kw/ton, which is meet the GreenMark baseline minimum efficiency requirement 0.85kw/ton
• There is big room to improve chiller plant efficiency:
Insert Footer24
Insert Footer25
Figure 3a
Insert Footer26
Figure 3b
Insert Footer27
Figure 3c
Insert Footer28
Insert Footer29
Insert Footer30
Insert subtitle here
Figure 5a
Insert Footer31
Figure 5b
Insert Footer32
Figure 5c
Insert Footer33
Figure 5d
Insert Footer34
Insert Footer35
Insert Footer36
Figure 6a
Insert Footer37
Figure 6b
Insert Footer38
Figure 6c
Insert Footer39
Figure 6d
Insert Footer40
Insert Footer41
Figure 7a
Insert Footer42
Figure 7b
Insert Footer43
Low Face VelocityAn Energy Conservation Option
forMake-Up Air Units
Presented by:Greg Owen, PE
October 4, 2000
Insert Footer44
Cleanroom facility design decisions must be economically
justified.
FACT:
Low Face Velocity
Insert Footer45
• Unit CFM - 43,500 CFM
• Site Elevation - 1500 Ft
• Summer Conditions - 96oF / 65oF
• Winter Conditions - -20oF
• Chilled Water - 39oF / 51oF
• Hot Water - 180oF / 150oF
• Supply Air Conditions - 55oF / 48.6oF
Make-Up Unit Design Conditions
Low Face Velocity
Insert Footer46
Elements That Affect Make-up Air Unit Energy Consumption
CoilSize
FilterSize
Fan CFM, Motor Hp
oF &RH%of OA
Under the control ofthe Design Engineer
oF &RH%
Low Face Velocity
Insert Footer47
FACE VELOCITIES CONSIDERED
• Unit CFM
Face Area
500FPM
350FPM
425
FPM
300FPM
Low Face Velocity
Insert Footer48
Low face velocities reduce air handling unit coil and filter static
pressure and result in lower energy consumption by the unit.
PREMISE #1
Low Face Velocity
Insert Footer49
FILTER DIFFERENTIAL PRESSURE
0
0.5
1
1.5
2
2.5
500 425 350 300(FPM)
Pre Filters Carbon Filters 95% Filters HEPA Filters
(INWG)
Low Face Velocity
Insert Footer50
COIL DIFFERENTIAL PRESSURE
0
0.2
0.4
0.6
0.8
1
1.2
1.4
(INWG)
500 425 350 300(FPM)
Preheat Cooling Dehum Reheat
Low Face Velocity
Insert Footer51
Energy savings from low face velocity systems reduce the operating costs of the units.
PREMISE #2
Low Face Velocity
Insert Footer52
Component Cost Impact
Larger Casing Increase Capital Cost
Larger Coils Increase Capital Cost
Increased Filter Count Constant Life Cycle Cost
Smaller Fan Motors Decreased Capital Cost
Reduced Infrastructure Decreased Capital Cost
ECONOMIC IMPACT FOR LOW FACE VELOCITY COMPONENTS
Low Face Velocity
Insert Footer53
MAKE-UP AIR UNIT MOTOR SELECTION
Static RPM Brake Hp
• 500 FPM 801 65.0
• 425 FPM 757 55.6
• 350 FPM 709 46.0
• 300 FPM 687 41.8
Low Face Velocity
Insert Footer54
Includes
• Fan, Motor & Drives
• Coils
• Filter Racks
• Humidifier
• Housing & Inlet
• EE Infrastructure Impact
MAKE-UP AIR UNIT COST ESTIMATE
Excludes• Filter Media
• Installation Cost
• Building Space
Low Face Velocity
Insert Footer55
Make-up Air Unit (MAU) Capital Cost Differential
• 500 FPM
• 425 FPM
• 350 FPM
• 300 FPM
• Base Cost
• +$4,820
• -$1,610
• +$9,450
Low Face Velocity
Insert Footer56
Energy Cost
• High Average Industrial / Commercial Rate
– Boston Edison
– $0.097/kWHr
• Low Average Industrial / Commercial Rate
– Portland General Electric
– $0.0382/kWHr
Low Face Velocity
Insert Footer57
• 425 FPM Unit $38,187 +37 Weeks (9.5 months)
MAU Electrical Operating Cost (High Rate)
• 500 FPM Unit $44,959 Base Condition
Pay Back PeriodUnit Size Cost/Yr.
• 350 FPM Unit $31,964 Immediate
• 300 FPM Unit $28,764 + 29 Weeks (7.25 months)
Low Face Velocity
Insert Footer58
• 425 FPM Unit $15,039 +94 Weeks (23.5 months)
MAU Electrical Operating Cost (Low Rate)
• 500 FPM Unit $17,705 Base Condition
Pay Back PeriodUnit Size Cost/Yr.
• 350 FPM Unit $12,588 Immediate
• 300 FPM Unit $11,328 + 77 Weeks (19.2 months)
Low Face Velocity
Insert Footer59
• Low face velocities do save energy & money.
• Return on Investment (ROI) is dependent on local energy rates.
• High tech companies generally require ROI’s of 12 months or less.
CONCLUSION
Low Face Velocity
Questions??
Low Face Velocity
Insert Footer61
Questions??
Low Face Velocity
Questions??
Insert Footer62
Insert subtitle here