Variable Refrigerant Volume Tech Ology
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Transcript of Variable Refrigerant Volume Tech Ology
© 2005 Daikin AC
Variable Refrigerant FlowOverview
Thomasena Philen– Technical Trainer
Daikin AC ( Americas), Inc.
National Educators & Trainers Conference
Las Vegas 2011
© 2005 Daikin ACSlide 2Presentation Title : Presenter Name : Date
Hea
t
OUTDOOR Unit
Low Pressure Vapour
INDOOR Unit
Low Pressure Liquid
Wa
rm a
ir e
xtr
acte
d a
nd
co
ol a
ir in
tro
du
ce
dHeat
exchanger
DX Refrigeration Cycle – Cooling Mode
© 2005 Daikin ACSlide 3Presentation Title : Presenter Name : Date
High Pressure Liquid
Hea
t
High Pressure Vapour
Coo
l a
ir e
xtr
acte
d a
nd
wa
rm a
ir in
tro
du
ce
d
INDOOR UnitOUTDOOR Unit
Heat
exchanger
DX Refrigeration Cycle – Heating Mode
© 2005 Daikin ACSlide 4Presentation Title : Presenter Name : Date
Comfort Cooling & Heating
Developed as a measure for humidity control
Overlaps process cooling in many applications
Americans think “Inside the Box”
1930’s Efficiency not an issue
R-12 – 64.7 BTU/lb
R-22 – 100.5 BTU/lb
R-410A – 116.8 BTU/lb
© 2005 Daikin ACSlide 5Presentation Title : Presenter Name : Date
Efficiency & Coil Size
Residential Market – Push for more efficiency
Green Building
R-22 & High Efficiency
Footprint & Technology
© 2005 Daikin ACSlide 6Presentation Title : Presenter Name : Date
Variable Air Volume/Zoning
Commercial VAV
Residential Zoning
Efficiency & End-user comfort generally applied to
the airside
© 2005 Daikin ACSlide 7Presentation Title : Presenter Name : Date
Compressor Multiple Step Control
Standard HVAC system
1 to 2 stages of capacity
Uses mechanical unloading techniques
VRV uses inverter technology
Electronic inverter varies compressor rotational speed in steps
50% 100% 52~230HzCompressor capacity Applied frequency
Load
Load
Unloader Principle Multi-Step Control Principle
© 2005 Daikin ACSlide 8Presentation Title : Presenter Name : Date
Design Conditions
Block Load
Peak Load
Diversity
© 2005 Daikin ACSlide 9Presentation Title : Presenter Name : Date
VRV-VRF
What is VRF, History & Concept
How it Operates
VRF Benefits
Efficiency & Capacity Performance
Installation & Design Flexibility
User Comfort
Latest Technology
The Future of VRF in North America
© 2005 Daikin ACSlide 10Presentation Title : Presenter Name : Date
What is VRF?Variable Refrigerant Flow
Also referred to as VRV ® – Variable Refrigerant Volume
VRV is a registered trademark
© 2005 Daikin ACSlide 11Presentation Title : Presenter Name : Date
Background of Development of VRF
1973 – Global oil crises
1979 – New energy efficiency laws passes in
Japan
1980 – Chiller design engineers challenged with
making a higher efficiency chiller
1982 – The worlds first VRF System is launched
© 2005 Daikin ACSlide 12Presentation Title : Presenter Name : Date
VRF Global History
VRF world first’s
19901982
World’s first VRF
system is
developed
20071987
VRF is launched globally
2003
Worlds first R410A
VRF
20081991 1998
First globally
available heat
recovery VRF
World’s first
R407C VRF
system is
developed
Worlds inverter
driven VRF
2005
First water cooled
VRF system is
launch in the USA
World’s first CO 2
VRF system is
developed
Industry changing
piping and defrost
technology
© 2005 Daikin ACSlide 13Presentation Title : Presenter Name : Date
Where does a VRF system position?
VRF has the following attributes:-
Energy Efficient
Tight Temperature Control
Quiet Operation
The Ability To Have Many Zones
Large Capacity (Modular Build Up)
Centralized Plant (long piping)
Advanced BAS Control
Premium Specification & Priced Product
VRF competes most naturally as a chiller.
(this doesn’t mean it can only compete with chillers)
© 2005 Daikin ACSlide 14Presentation Title : Presenter Name : Date
VRF Concept
Multiple indoor units connected to one outdoor unit
Up to 62 on a single refrigerant piping network
Available in either air cooled or water cooled
© 2005 Daikin ACSlide 15Presentation Title : Presenter Name : Date
VRF Concept Think of a VRF system as a chiller that circulates refrigerant to each
zone instead of water
A heat pump system is equivalent to a 2 pipe chiller
Major benefit is smaller heat/cool changeover zones due to the
modular build up
A heat recovery system is equivalent to a 4 pipe chiller system
6 Ton
6 Ton
Heat recovery
Cooling Cooling Heating Heating
12 Ton
Heat Pump
© 2005 Daikin ACSlide 16Presentation Title : Presenter Name : Date
T(sec)
+V
-VFrequency (Hz)
T(sec)
+V
-VFrequency (Hz)
Inverter Technology
© 2005 Daikin ACSlide 17Presentation Title : Presenter Name : Date
Start with smooth inverter voltage output current wave
Smooth waveRough wave
DC Inverter
© 2005 Daikin ACSlide 18Presentation Title : Presenter Name : Date
ulse mplitude odulation
I(A)Vc
I(A)
VcSW
Standard rectifier circuit (without PAM) provides a smooth, steady voltage. However, under peak load conditions, efficiency is lost
due to modulation of the current wave.
Daikin rectifier circuit (with PAM) adds a coil and switching contact that cycles at 20 kHz. This creates an improved current wave resulting in
10% higher compressor efficiency than standard inverter systems.
Pulse Amplitude Modulation (PAM)
© 2005 Daikin ACSlide 19Presentation Title : Presenter Name : Date
High Efficiency in Part-Load conditions
Very low startup amperage
No locked rotor amps
No stress on windings or compressor
frame
No “light flicker”
Lubrication of bearings increases
before speed increase
System pressures increase gradually
reducing noise and stress on piping
Quiet compressor startup
Better Dehumidification
Fewer start/stop cycles
As room temperature nears set point
capacity is automatically throttled down”
Very consistent comfort levels
Capacity is adjusted as the load changes Low
Ambient control - Standard
Inverter Benefits
© 2005 Daikin ACSlide 20Presentation Title : Presenter Name : Date
0 1 2 3 4 5Time [Hour]
122
86
104
68
50
32
Te
mp
era
ture
F
150
90
120
60
30
0 Fre
qu
en
cy o
f co
mp
resso
r [H
z]
0 1 2 3 4 5Time [Hour]
122
86
104
68
50
32
Te
mp
era
ture
F
150
90
120
60
30
0 Fre
qu
en
cy o
f co
mp
resso
r [H
z]Inverter Unit
Non-Inverter Unit Outdoor temp: 32F Set Temp: 73F
Room Temp.
Outlet Temp.
Compressor Freq
Room Temp
Outlet Temp
Compressor Freq.
Operation Cycle – How it Looks
© 2005 Daikin ACSlide 21Presentation Title : Presenter Name : Date
Electronic control of the compressor
High outdoor ambient temperature
Temperature sensors identify high temperature condition
Compressor speed is electronically reduced to limit high side pressure and energy usage
Reduces energy usage during peak conditions
Great heating performance
Compressor increases speed during cold outdoor ambient conditions
Generates higher head pressure, discharge gas temperatures and discharge air temperatures
Achieves the same heat output as competitive systems with electric booster heat without using the extra energy
Additional Inverter Benefits
© 2005 Daikin ACSlide 22Presentation Title : Presenter Name : Date
Neodymium
© 2005 Daikin ACSlide 23Presentation Title : Presenter Name : Date
CompressorsDigitally Commutated (DC) Motors in both Swing and Scroll
© 2005 Daikin ACSlide 24Presentation Title : Presenter Name : Date
Advanced VRF Controls
Individual Zone Controllers Multi-zone Controllers
Open Protocol Gateways Adapter PCB’s
© 2005 Daikin ACSlide 25Presentation Title : Presenter Name : Date
Heat Transfer Media The commonly used methods of Heat Transfer in Air Conditioning Solutions each
exercise different operational characteristics regards adding or removing heat energy to a conditioned space as follows: -
This diagram represents the Energy Transfer possible per lb of media due to the performance characteristic of the fluid used.
Water
2.6 watts/lb
25 watts/lb
Refrigerant
Air
0.14 watts/lb
VAV VWV VRF
Why Refrigerant?
© 2005 Daikin ACSlide 26Presentation Title : Presenter Name : Date
Comparable Chilled Water System
Cooling tower
EXP tankFCUAHU
Header
Chiller
Pump
Boiler
Valves
Top floor
Machine Room
Building floors
Water pipe
And also …
Complicated installation
Complicated maintenance
Multiple
Manufacturers
“Blame Game” When
System Does Not
Operate Correctly
© 2005 Daikin ACSlide 27Presentation Title : Presenter Name : Date
VRF Concept
Top floor
Building floors
Space-conscious design
Simple system
Individual control
Simple Installation
Simple MaintenanceRemote controllers
One Point Of
Contact For
Technical Support
Simple Operation
One Manufacturer
© 2005 Daikin ACSlide 28Presentation Title : Presenter Name : Date
Current Situation All VRF Equipment is currently
sold under a waiver from the DOE
No available testing and rating standard
This means that only full load EER and COP can be published
Advantage can not be taken of the true VRV system benefits:-
Part load performance
Low ambient heating capabilities
© 2005 Daikin ACSlide 29Presentation Title : Presenter Name : Date
AHRI 1230 is a testing and rating
standard specially designed for VRF
type equipment.
This will allow us to show VRV
efficiency levels for:
Full Load
Part Load
Heat Recovery
We have been working on the VRF
testing and rating standard for the
last 5 years
Now, the hard work has paid off
What is AHRI 1230?
© 2005 Daikin ACSlide 30Presentation Title : Presenter Name : Date
Explanation of the Ratings All efficiency values will be based on the total system
performance including:-
Outdoor unit power input
Power input of indoor units
Piping loss correction factors to reflect real life building
performance
With the new VRVIII we can now promote efficiency levels
for Ducted, Ductless and Mixed combinations
Rating
Daikin VRVIII
PB Series Other VRF
System Full Load EER ?
System Full Load COP ?
System Low Ambient COP (17°F) ?
IEER (Part Load Operation) ?
SCH (Heat Recovery Mode) ?
© 2005 Daikin ACSlide 31Presentation Title : Presenter Name : Date
AHRI 1230 vs. DOE Waiver
AHRI 1230 does not replace the DOE wavier
DOE has to officially recognize AHRI 1230 before the waiver
becomes obsolete.
This may happen as soon as January 2012
AHRI 1230 numbers can still be published because
they were cited in Daikin’s waiver application to the
DOE
© 2005 Daikin ACSlide 32Presentation Title : Presenter Name : Date
Air Cooled & Water Cooled VRV
Systems from 65-300MBH can be
certified with an AHRI rating
Systems above 300MBH can be rated to
the standard but they are not part of the
certification program
Program was written before larger VRF
systems were available.
Will be updated in the future
Systems under 65MBH such as VRV-S or
Multi or single splits are currently covered
by AHRI 210/240.
Which products are covered?
© 2005 Daikin ACSlide 33Presentation Title : Presenter Name : Date
The Biggest VRF Design Mistakes
Positioning VRF as a “big multi split”
This is a chiller that circulates refrigerant
instead of water
FCU in every room
Think of it as you would designing a
VAV system
Ductless focus
This leads to a FCU in every room
Over 55% of VRF FCU sold world wide are ducted
The whole application must be VRF
© 2005 Daikin ACSlide 34Presentation Title : Presenter Name : Date
System Capacity Control
1 2 3 4
EACH INDOOR CONTROLS ITS CAPACITY
VIA PID CONTROL AND AN E.E.V.
CONDENSING UNIT ADJUST THE INVERTER
COMPRESSOR TO PROVIDE THE REQUIRED
CAPACITY (Large or Small)
INDEPENDENT
BRAIN
T3
T4
T2
T1
Controller
(TSET)
CPU(PID Control)
LEGEND
T1: Refrigerant Liquid Line Temp.
T2: Refrigerant Suction Line Temp.
T3: Return Air / Remote Sensor
Temp.
T4: Controller Temperature Sensor
TSET: Controller Set Point Temp.
© 2005 Daikin ACSlide 35Presentation Title : Presenter Name : Date
8 & 10 Ton Outdoor UnitsThe Capacity Build-up
© 2005 Daikin ACSlide 36Presentation Title : Presenter Name : Date
6,8,10,12*Ton 12,14,16,18,20, 30 Ton
6 8 10 12 14 16 18 20
460 v
208/230 v
VRF
H/P H/R
Air Cooled 3ph Outdoor Unit Range
© 2005 Daikin ACSlide 37Presentation Title : Presenter Name : Date
6 & 7 Ton 12,14Ton
Water Cooled Outdoor Unit Range
6 7 12 14 18 21
208/230VVRF-W
18,21Ton
Geothermal Application With Limits
© 2005 Daikin ACSlide 38Presentation Title : Presenter Name : Date
Air Cooled Single Phase Outdoor Unit Range
3 4
208/230VVRF
© 2005 Daikin ACSlide 39Presentation Title : Presenter Name : Date
39
Indoor Type
Capacity Range
MBH 07 09 12 18 24 30 36 42 48
Tons 0.6 0.75 1 1.5 2 2.5 3 3.5 4
Vertical Air Handling
Ceiling Mounted Cassette Type
Ceiling Mounted Built-in Type
Concealed Ceiling Unit (Medium Static)
Slim Duct Concealed Ceiling Mounted FXDQ-M
Floor Standing Type
Floor Standing Type (uncased)
Ceiling Suspended Type
Wall Mounted Type
2x2
3x3
© 2005 Daikin ACSlide 40Presentation Title : Presenter Name : Date
What About Efficiency?
Typical energy consumption in office building
How can VRF reduce energy costs?
Air Conditioning 47%
Other utilities
20%Lighting 33%
© 2005 Daikin ACSlide 41Presentation Title : Presenter Name : Date
Partial Load Performance (VRV)
0.0
2.0
4.0
6.0
8.0
10.0
12.0
14.0
16.0
18.0
10% 20% 30% 40% 50% 60% 70% 80% 90% 100%Load
EER75%
595
340
680
340
170
425
510
255
85
Operation Hours
of Main Machine75% of total operation
hours- less than 70% of full load
Partial Load System Performance VRF
© 2005 Daikin ACSlide 42Presentation Title : Presenter Name : Date
Standard VRF Capacities at Low Ambient
76
80
84
86
88
91
93
97
102
106
108
108
108
108
108
108
108
5.5
9.5
13
15
17
19
22
26
30
35
39
44
47
51
54
57
60
AM
BIE
NT
TE
MP
(F
)
70% of Capacity at 5.5F
© 2005 Daikin ACSlide 43Presentation Title : Presenter Name : Date
3.99
2.70
0.0
1.0
2.0
3.0
4.0
72 MBH Heat
Recovery @
47F
72 MBH Heat
Recovery @
5.5F
But What About Efficiency?
COP Comparing a 6 Ton VRF Heat
Recovery outdoor only unit at -
Full load in heating @ 47°F
COP of 3.99
Full load heating at @ 5.5°F
COP of 2.76
Efficiency increases at part load
© 2005 Daikin ACSlide 44Presentation Title : Presenter Name : Date
Hotel 4 Pipe with Chiller vs. VRF
91,000 ft2 Hotel
4 Pipe System
80% Gas Boiler
200 ton Water Cooled Chiller – 0.65 kW/ton
Heat Recovery VRF
(5) 16 ton
(4) 20 ton
$0.10/kWh electricity cost
$1.30/therm natural gas cost
Annual Energy Cost Conventional VRV III Savings
New York $ 132,608 $ 93,014 $ 39,594 30%
Atlanta $ 124,297 $ 90,366 $ 33,931 27%
Phoenix $ 117,413 $ 89,270 $ 28,143 24%
St. Louis $ 134,985 $ 95,492 $ 39,493 29%
© 2005 Daikin ACSlide 45Presentation Title : Presenter Name : Date
Office Rooftop VAV vs. VRF
11,000 ft2 Office
Rooftop Packaged VAV
30 ton - 9.5 EER w/economizer & hot water reheat terminal boxes
Heat Recovery VRF
(1) 12 ton
(2) 8 ton
$0.10/kWh electricity cost
$1.30/therm natural gas cost
Annual Energy Cost Conventional VRV III Savings
New York $ 9,796 $ 7,138 $ 2,658 27%
Atlanta $ 9,562 $ 7,274 $ 2,288 24%
Phoenix $ 10,216 $ 7,789 $ 2,427 24%
St. Louis $ 10,323 $ 7,528 $ 2,795 27%
© 2005 Daikin ACSlide 46Presentation Title : Presenter Name : Date
Total Piping length
1,000 ft (3280ft)
165 ft
(295ft)
50 ft
Actual
piping length(liquid line)
492 ft (540ft)
Top
130 ft
(295ft)
No oil traps
Sight Glasses
Driers
VRF Piping Flexibility
© 2005 Daikin ACSlide 47Presentation Title : Presenter Name : Date
Eldorado Business
Tower
High-rise office building
In a
© 2005 Daikin ACSlide 48Presentation Title : Presenter Name : Date
Location : Sao Paul BZ.
Office building
Height : 33F + B3
Total Floor area : 728,178 ft2
Typical floor area: 17,222 ft2
Completion : 2007
Building Profile
© 2005 Daikin ACSlide 49Presentation Title : Presenter Name : Date
Location of CDU
217 ft
167 ft
How to
overcome
higher level
difference
384 ft
© 2005 Daikin ACSlide 50Presentation Title : Presenter Name : Date
CDU on Upper Roof
217 ft
167 ft
1454 Tons
© 2005 Daikin ACSlide 51Presentation Title : Presenter Name : Date
CDU on Lower Roof
217 ft
167 ft
1259 Tons
© 2005 Daikin ACSlide 52Presentation Title : Presenter Name : Date
Standard refrigerant balancing joint and header
HEADER
JOINT
Simple Pre-Engineered Piping Installation
© 2005 Daikin ACSlide 53Presentation Title : Presenter Name : Date
Wide range of indoor capacity to fit to your room
Ducted and Ductless
0.6 Ton
8 TonRoom 1
Room 2
Design Flexibility
© 2005 Daikin ACSlide 55Presentation Title : Presenter Name : Date
It is suitable for putting an outdoor unit on each floor or in mechanical rooms
Duct
Louver
Window
Exhaust
duct
Suction
Suction louver
Exhaust duct
Up to 0.32” W.G
Design Flexibility-Indoor Installation
© 2005 Daikin ACSlide 56Presentation Title : Presenter Name : Date
Flexible Installation
Floor by floor installation
and commissioning
Ideal for new construction or
renovation projects
Time and cost saving
© 2005 Daikin ACSlide 57Presentation Title : Presenter Name : Date
They fit in the elevator
SMALL FOOTPRINT
Easy Installation
© 2005 Daikin ACSlide 58Presentation Title : Presenter Name : Date
Ideal for Random Occupancy
Individual Operation
© 2005 Daikin ACSlide 59Presentation Title : Presenter Name : Date
30-Ton
Refrigerant
Pipework
6-Ton
Ductwork
“ VRF meets VAV”
Heat Transfer Media - Installation
© 2005 Daikin ACSlide 60Presentation Title : Presenter Name : Date
Simple, Easy, Flexible Wiring Installation A simple 2 wire daisy chain communication system
16-18 gauge AWG Not polarity sensitive
Up to 6560ft of total system wiring
Longest length up to 3280ft
Auto Addressing
Cost savings at installation
Cost savings at commissioning
© 2005 Daikin ACSlide 61Presentation Title : Presenter Name : Date
Low Operating Sound Levels
Ductless operating sound levels as low as 27dB(A)
Ducted operating sound levels as low as 29dB(A)
© 2005 Daikin ACSlide 62Presentation Title : Presenter Name : Date
Users Comfort Easy Maintenance & Repair
Self-Diagnostics
Should an error occur, a fault code is displayed
Up to 66 Alphanumeric malfunction codes
Each code relates to an indoor, outdoor or system fault
Automatic storage of data for improved repair response
time
Operating
Automatic
operation
data storage
of the last 3
minutes just
before the
malfunction
Malfunction
© 2005 Daikin ACSlide 63Presentation Title : Presenter Name : Date
Compressor Back Up Operation
OperationTrouble
Alarm
INV
Activated by remote
control or field setting
Operation
INV INV
INV
Trouble
INV
© 2005 Daikin ACSlide 64Presentation Title : Presenter Name : Date
Oil Recovery
The Oil separator recovers up to
95% of the migrating oil
Logic checks the integrated
amount of oil leaving the
compressor
Automatic oil return starts after 2
hours working after cold start
Duration of up to 6 minutes.
Every 8 hours of accumulated
operation
Centrifugal oil separator
© 2005 Daikin ACSlide 65Presentation Title : Presenter Name : Date
High/Low Pressure Gas Pipe
Liquid pipe
Suction gas type
BS unit
Heating HeatingHeating Heating
LL LL LL LL
Defrost Defrost
Defrost Operation
Each outdoor completes defrost operation individually, in doing so heating operation
continues at each indoor unit. (Manifolded system example)
© 2005 Daikin ACSlide 66Presentation Title : Presenter Name : Date
ASHRAE HQ Renovation Success Story
28 tons of VRF heat recovery & 4
tons of single phase VRF were
installed into the first floor office
space and learning center
In addition to this 5 tons of
Inverter Driven Splits were
installed in the data room
The VRF systems helped
ASHRAE in achieving LEED
Platinum
© 2005 Daikin ACSlide 67Presentation Title : Presenter Name : Date
Worlds First CO2 VRF This last year, the worlds first CO2 based VRF System
was released for sale in Europe
One of the most environmentally friendly
refrigerants with a GWP of 1
New Technologies
New optimized swing compressor to handle the
higher pressures and reduce leakage
Dual stage intercooler to help control the
refrigerant and reduce pipe dimensions
New 3 row heat exchanger and pass pattern for
optimum heat transfer
© 2005 Daikin ACSlide 68Presentation Title : Presenter Name : Date
Conclusion
VRF provides and alternative, realistic choice to traditional central systems.
It captures many of the features of chilled water systems, while incorporating the simplicity of DX systems.
Allows for the correct equipment selection with both air cooled and water cooled equipment
It brings some of the latest technology to the market and provides a higher degree of reliability, comfort and energy efficiency that is expected from today's consumer.
© 2005 Daikin ACSlide 69Presentation Title : Presenter Name : Date
Thank You
Any Questions?