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Transcript of Introduction to Variable Refrigerant Flow Systems Allen Anaya Application Consultant WM Carroll, LLC...
NM ASHRAE – Introduction to Variable Refrigerant Systems
1
Introduction to Variable Refrigerant Flow Systems
Allen AnayaApplication Consultant
WM Carroll, LLCPh: 505-268-6776Cell: 505-385-7338Fax: 505-255-1329
E-Mail: [email protected]
11/16/2010
NM ASHRAE – Introduction to Variable Refrigerant Systems
2
Agenda
• What is VRF? –History – Concept
• How does VRF Operate? – Refrigerant– Compressor– Fan Coil
• Important Standards– ASHRAE Standard 15– AHRI-1230-2010
• VRF Benefits – Installation & Design Flexibility – User Comfort
• The Future of VRF in North America
11/16/2010
NM ASHRAE – Introduction to Variable Refrigerant Systems
3
V R F
What is VRF?
Variable Refrigerant Flow
Also referred to as VRV ® – Variable Refrigerant Volume
VRV is a registered trademark
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NM ASHRAE – Introduction to Variable Refrigerant Systems
11/16/2010 4
• 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
VRF History
NM ASHRAE – Introduction to Variable Refrigerant Systems
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• VRF world first’s
VRF Global History
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
6
VRF47%
Chillers/Central Plant25%
Packaged/Splits28%
Development of VRF Market Japan Buildings under 70,000ft2
• By 1996 VRF had established itself as a proven technology with 34% market share• With increased market acceptance as a replacement to traditional applied central
systems VRF achieved 47% market share by 2001– 9% share was taken from the chiller/central plant market – The 4% taken from the split and package section was through replacing VAV
projects and allowing customer to afford the “chiller” they originally wanted
VRF34%
Chillers/CentralPlant34%
Packaged/Splits32%
1996
2001
7
VRF32%
Chillers/CentralPlant33%
Packaged/Splits35%
Development of VRF Market Japan Buildings over 70,000ft2
• Further evidence of acceptance can be seen by the increase in VRF market share in the larger applications– 12% share taken from the chiller/central plant market
• This trend was common in Europe, Australia and now North America
VRF15%
Chillers/CentralPlant45%
Packaged/Splits40%
1996
2001
NM ASHRAE – Introduction to Variable Refrigerant Systems
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VRF Concept
Pump
Pump
Coolingtower
Water piping
AHUFCU FCU
For cooling
For heating
2 heat sourcesManaged by
engineer
Complicated
Inefficient part load operation
Outdoorunit
indoorunit
Refrigerant piping
Space-conscious design
Simple system
Energy efficient
Individual controlRemotecontroller
Simple Operation
Chiller
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VRF
NM ASHRAE – Introduction to Variable Refrigerant Systems
11/16/2010 9
VRF Concept
Top floor
Building floors
Space-conscious design
Simple system
Individual control
Simple Installation
Simple MaintenanceRemote controllers
Simple Operation
One Point Of Contact For Technical Support
One Manufacturer
NM ASHRAE – Introduction to Variable Refrigerant Systems
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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
Cooling Cooling Heating Heating
Heat Pump Heat Recovery
12 Ton
6 Ton
6 Ton
Cooling Cooling Heating Heating
NM ASHRAE – Introduction to Variable Refrigerant Systems
1111/16/2010
VRF ConceptHEAT RECOVERY VRF
NM ASHRAE – Introduction to Variable Refrigerant Systems
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VRF ConceptAdvanced Zoning Capabilities
• Total comfort for occupants– Office buildings– Hospitals– Assisted living facilities– Schools– Hotels– Retail space
• Reduced operating costs– Shut down zones that are not in use
• Variable capacity design enables maximization of diversity– Each zone is individually controlled
NM ASHRAE – Introduction to Variable Refrigerant Systems
13
VRF ConceptWhere 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
• Special Advantage of Modular Design: If you loose 1 condenser, you only loose a small part of the building; NOT the entire building.
• Modular design only requires installation of a zone as required; entire cooling and heating system does not have to be piped during initial construction
VRF competes most naturally as a chiller.(this doesn’t mean it can only compete with chillers)11/16/2010
NM ASHRAE – Introduction to Variable Refrigerant Systems
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Agenda • What is VRF?
– History – Concept
• How does VRF Operate? – Refrigerant– Compressor– Fan Coil
• Important Standards– ASHRAE Standard 15– AHRI-1230-2010
• VRF Benefits – Installation & Design Flexibility – User Comfort
• The Future of VRF in North America
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NM ASHRAE – Introduction to Variable Refrigerant Systems
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HEAT TRANSFER MEDIA
Water
8.98 Btuh/lb
88.2 Btuh/lb
Refrigerant
Air
0.46 Btuh/lb
VAV VWV VRF
How does VRF Operate?
NM ASHRAE – Introduction to Variable Refrigerant Systems
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Inverter Drive SystemT(sec)
+V
-VFrequency (Hz)
T(sec)
+V
-VFrequency (Hz)
Inverter Box
• The inverter control adjusts the supply frequency• Thus the rotational speed of the compressor is controlled• Exactly the right amount of refrigerant gas is pumped to meet the cooling requirements
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How does VRF Operate?
NM ASHRAE – Introduction to Variable Refrigerant Systems
17
Inverter = Energy Efficiency
Capacity is regulated when outdoor temperature changes
Startup time is reduced by 1/3
The start/stop cycle is repeated less frequently – reducing energy loss at startup
As room temperature nears set point capacity is automatically “throttled down”
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How does VRF Operate?
NM ASHRAE – Introduction to Variable Refrigerant Systems
Other Inverter Benefits• Very low startup amperage• No locked rotor amps• No stress on windings or compressor frame• No “light flicker”• Lubrication of bearings increases before speed
increases• System pressures increase gradually reducing
noise and stress on piping• Quiet compressor startup
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How does VRF Operate?
NM ASHRAE – Introduction to Variable Refrigerant Systems
19
Other Inverter Benefits• Longer Run Periods at Lower Capacities
– Better Dehumidification– Fewer compressor starts mean less wear and tear on
the compressor = longer life!– Lower compressor speeds = higher system efficiency
since the condenser coil surface remains large in relation to reduced capacity
– Higher efficiency = Lower electric bills!
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How does VRF Operate?
NM ASHRAE – Introduction to Variable Refrigerant Systems
20
Inlet
Outlet
PID ControlSignal
ValveMechanism
Electronic Expansion Valve (EEV) Control• EEV’s receive ‘PID’ control feedback to adjust
refrigerant volume– Up to 2000 steps of control
Continual management of flow rate controls super heat and coil capacity for optimum performance and energy efficiency
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How does VRF Operate?
NM ASHRAE – Introduction to Variable Refrigerant Systems
21
Proportional, Integral & Derivative (PID)• Electronic expansion valve using PID
– Continuously adjusts the refrigerant volume in response to load variations
– Comfortable room temperature is maintained without the wide temperature swings of a conventional system
T4
T2
T1
Controller(TSET)
CPU(PID Control)
LEGENDT1: Refrigerant Liquid Line Temp.T2: Refrigerant Suction Line Temp.T3: Return Air / Remote Sensor Temp.T4: Controller Temperature SensorTSET: Controller Set Point Temp.
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How does VRF Operate?
NM ASHRAE – Introduction to Variable Refrigerant Systems
11/16/2010 22
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)
T3
T4
T2
T1
Controller(TSET)
CPU(PID Control)
LEGENDT1: Refrigerant Liquid Line Temp.T2: Refrigerant Suction Line Temp.T3: Return Air / Remote Sensor Temp.T4: Controller Temperature SensorTSET: Controller Set Point Temp.
How does VRF Operate?
NM ASHRAE – Introduction to Variable Refrigerant Systems
23
• Efficiency improved in all areas compared to conventional AC motors, especially at low speeds
DC Fan Motor Efficiency
Magnet
DC Fan MotorDC Fan MotorAC Fan MotorAC Fan Motor
70
80
90
100
10 20 30 40 50 60 70 80 90 100 110
Revolutions [rps]M
otor
Effi
cien
cy [%
]
DC Motor
AC Motor
Approx.40%
increase
Approx.20%
increase
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How does VRF Operate?
NM ASHRAE – Introduction to Variable Refrigerant Systems
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Agenda • What is VRF?
– History – Concept
• How does VRF Operate? – Refrigerant– Compressor– Fan Coil
• Important Standards– ASHRAE Standard 15– AHRI-1230-2010
• VRF Benefits – Installation & Design Flexibility – User Comfort
• The Future of VRF in North America
11/16/2010
NM ASHRAE – Introduction to Variable Refrigerant Systems
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Overview of ASHRAE Std 15
• Specifies minimum safety requirements in the event of a refrigerant leak into an occupied space.
• Safety Issues:
1. Flammable refrigerants causing injury or death by fire.
2. Toxic refrigerants possibly causing injury or death by poisoning.
3. Non flammable and non toxic refrigerants causing injury or death by asphyxiation from oxygen displacement.
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Important Standards / Code Information
NM ASHRAE – Introduction to Variable Refrigerant Systems
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Scope of Standard 15
• Scope• 2.1 This standard establishes safeguards for life, limb, health, and
property and prescribes safety requirements.• 2.2 This standard applies
a. To the design, construction, test, installation, operation, and inspection of mechanical and absorption refrigeration systems, including heat pump systems used in stationary applications,
b. To modifications including replacement of parts or components if they are not identical in function and capacity, and
c. To substitutions of refrigerant having a different designation.
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Important Standards / Code Information
NM ASHRAE – Introduction to Variable Refrigerant Systems
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Basic Steps
• Determine volume of smallest occupied space (cu.ft.)• Determine refrigerant qty potential of the smallest
occupied space (lbs)• Check that refrigerant qty potential doesn’t exceed the
allowable Refrigerant Concentration Limit (RCL) per 1000cuft.
• Check routing of piping (must be non obstructive) in corridors, lobbies and versus the RCL requirements
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Important Standards / Code Information
NM ASHRAE – Introduction to Variable Refrigerant Systems
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Compliance Responsibilities
• Specifies application, not manufacturing requirements.• Impossible for a unit to comply, only an application can comply.• Design engineer is responsible for assessment and compliance.
– ASHRAE Std 15 has an easy to follow “Users Handbook” that can be purchased by the Engineer / Contractor.
• All units should comply with mandatory U.S. manufacturing standards.
• ASHRAE Std 15 equivalent standards exist in Europe and Asia and are just as stringent. “Direct” systems such as VRF are the most common solution in these regions and are applied successfully to meet these standards
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Important Standards / Code Information
NM ASHRAE – Introduction to Variable Refrigerant Systems
11/16/2010 29
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
Important Standards / Code Information
30
AHRI 1230• The industry has been working on
the VRF testing and rating standard for the last 5 years– Now, the hard work has paid off!
• We are proud to announce that the VRF testing and rating standard, AHRI 1230, will be launched and the efficiency levels will be in ASHRAE 90.1 by January 2011
Important Standards / Code Information
NM ASHRAE – Introduction to Variable Refrigerant Systems
11/16/2010 31
AHRI-1230 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 this; 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) ?
Important Standards / Code Information
NM ASHRAE – Introduction to Variable Refrigerant Systems
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Agenda • What is VRF?
– History – Concept
• How does VRF Operate? – Refrigerant– Compressor– Fan Coil
• Important Standards– ASHRAE Standard 15– AHRI-1230-2010
• VRF Benefits – Installation & Design Flexibility – User Comfort
• The Future of VRF in North America
11/16/2010
NM ASHRAE – Introduction to Variable Refrigerant Systems
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VRF/VRV Benefits
Outdoor Unit
Indoor Units
Main features Energy Saving Individual control Long refrigerant Piping Wide range of units Low Noise Level
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NM ASHRAE – Introduction to Variable Refrigerant Systems
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Users Comfort Accurate Temperature Control
30
25
20
15
10 20 30 40 50 60 70
Cooling mode with VRF System:
Min..
Conventional A/C
VRF system
Room
Te
mpera
ture
Down to 1F
VRF/VRV Benefits
NM ASHRAE – Introduction to Variable Refrigerant Systems
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• Ductless operating sound levels as low as 28dB(A) • Ducted operating sound Levels as low as 35dB(A)
35
41
38
44
39
45
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
12 MBH 24 MBH 36MBH
Standard Ducted Sound Levels
Low Fan High Fan
28
31
29
3433
40
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
12 MBH 24 MBH 36MBH
Cassette Ductless Sound Levels
Low Fan High Fan
User Comfort Low Operating Sound
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VRF/VRV Benefits
NM ASHRAE – Introduction to Variable Refrigerant Systems
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Lightweight, Small & Flexible• Indoor units are lightweight and compact
– Fit into nearly any ceiling space• Outdoor units don’t require special cranes or
lifting devices– Can be hauled using a hand-lift and the
building elevator• Installation by floor
– If necessary, installation can be done by floor
• No need to wait until the full system is installed to test the system sections
ConventionalSystem
VRVSystem
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VRF/VRV Benefits
NM ASHRAE – Introduction to Variable Refrigerant Systems
11/16/2010 37
Refrigerant R-410A
Air
Water
Ø 1-1/8“ Ø 1/2“ Ø 2“ Ø 2“
Ø 25 ½“
49“
16“
24“
24“
or
Always twoducts needed
or
Reduced Intallation Space For 10 Tons capacity
VRF/VRV Benefits
NM ASHRAE – Introduction to Variable Refrigerant Systems
3811/16/2010
Advanced Controls Solutions
Fire alarm Security
Ethernet
Power supply facility
BMS
~
~
(for use in Lon Worksnetworks)
HRV
VRF/VRV Benefits
NM ASHRAE – Introduction to Variable Refrigerant Systems
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Agenda • What is VRF?
– History – Concept
• How does VRF Operate? – Refrigerant– Compressor– Fan Coil
• Important Standards– ASHRAE Standard 15– AHRI-1230-2010
• VRF Benefits – Installation & Design Flexibility – User Comfort
• The Future of VRF in North America 11/16/2010
NM ASHRAE – Introduction to Variable Refrigerant Systems
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Worlds First CO2 VRF• This 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
The Future of VRF in North America
NM ASHRAE – Introduction to Variable Refrigerant Systems
4111/16/2010
What’s Next: Domestic and Hot Water Heating
The Future of VRF in North America
NM ASHRAE – Introduction to Variable Refrigerant Systems
11/16/2010 42
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.
NM ASHRAE – Introduction to Variable Refrigerant Systems
43
Introduction to Variable Refrigerant Flow Systems
Allen AnayaApplication Consultant
WM Carroll, LLCPh: 505-268-6776Cell: 505-385-7338Fax: 505-255-1329
E-Mail: [email protected]
Thank You!
11/16/2010