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Introduction to Variable Refrigerant Flow Systems
Allen Anaya Application Consultant WM Carroll, LLC Ph: Cell: Fax: 11/16/2010 NM ASHRAE – Introduction to Variable Refrigerant Systems
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NM ASHRAE – Introduction to Variable Refrigerant Systems
Agenda What is VRF? History Concept How does VRF Operate? Refrigerant Compressor Fan Coil Important Standards ASHRAE Standard 15 AHRI 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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NM ASHRAE – Introduction to Variable Refrigerant Systems
What is VRF? V R F Flow Refrigerant Variable Also referred to as VRV ® – Variable Refrigerant Volume VRV is a registered trademark 11/16/2010 NM ASHRAE – Introduction to Variable Refrigerant Systems 3
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NM ASHRAE – Introduction to Variable Refrigerant Systems
VRF History 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 11/16/2010 NM ASHRAE – Introduction to Variable Refrigerant Systems
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NM ASHRAE – Introduction to Variable Refrigerant Systems
VRF Global History VRF world first’s World’s first CO 2 VRF system is developed VRF is launched globally First globally available heat recovery VRF Worlds first R410A VRF Industry changing piping and defrost technology 1982 1987 1990 1991 1998 2003 2005 2007 2008 World’s first VRF system is developed Worlds inverter driven VRF First water cooled VRF system is launch in the USA World’s first R407C VRF system is developed 11/16/2010 NM ASHRAE – Introduction to Variable Refrigerant Systems
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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 2001 1996
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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 1996 2001
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Chiller VRF VRF Concept Simple system Complicated Energy efficient
Outdoor unit indoor Refrigerant piping Space-conscious design Simple system Energy efficient Individual control Remote controller Simple Operation Pump Cooling tower Water piping AHU FCU For cooling heating 2 heat sources Managed by engineer Complicated Inefficient part load operation 11/16/2010 NM ASHRAE – Introduction to Variable Refrigerant Systems
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NM ASHRAE – Introduction to Variable Refrigerant Systems
VRF Concept Simple system One Manufacturer Space-conscious design Top floor Individual control Building floors One Point Of Contact For Technical Support Simple Installation Simple Operation Remote controllers Simple Maintenance 11/16/2010 NM ASHRAE – Introduction to Variable Refrigerant Systems
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NM ASHRAE – Introduction to Variable Refrigerant Systems
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 Heat Pump Heat Recovery 6 Ton 12 Ton Cooling Cooling Heating Heating Cooling Cooling Heating Heating 11/16/2010 NM ASHRAE – Introduction to Variable Refrigerant Systems
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NM ASHRAE – Introduction to Variable Refrigerant Systems
VRF Concept HEAT RECOVERY VRF 11/16/2010 NM ASHRAE – Introduction to Variable Refrigerant Systems
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VRF Concept Advanced 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 11/16/2010 NM ASHRAE – Introduction to Variable Refrigerant Systems
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Where does a VRF system position?
VRF Concept 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 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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NM ASHRAE – Introduction to Variable Refrigerant Systems
Agenda What is VRF? History Concept How does VRF Operate? Refrigerant Compressor Fan Coil Important Standards ASHRAE Standard 15 AHRI 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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NM ASHRAE – Introduction to Variable Refrigerant Systems
How does VRF Operate? HEAT TRANSFER MEDIA Water 8.98 Btuh/lb 88.2 Btuh/lb Refrigerant Air 0.46 Btuh/lb VAV VWV VRF 11/16/2010 NM ASHRAE – Introduction to Variable Refrigerant Systems
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NM ASHRAE – Introduction to Variable Refrigerant Systems
How does VRF Operate? Inverter Drive System T(sec) +V -V Frequency (Hz) 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 Inverter Box T(sec) +V -V Frequency (Hz) 11/16/2010 NM ASHRAE – Introduction to Variable Refrigerant Systems
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How does VRF Operate? Inverter = Energy Efficiency
The start/stop cycle is repeated less frequently – reducing energy loss at startup As room temperature nears set point capacity is automatically “throttled down” Capacity is regulated when outdoor temperature changes Startup time is reduced by 1/3 11/16/2010 NM ASHRAE – Introduction to Variable Refrigerant Systems
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How does VRF Operate? 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 11/16/2010 NM ASHRAE – Introduction to Variable Refrigerant Systems
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Other Inverter Benefits
How does VRF Operate? 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! 11/16/2010 NM ASHRAE – Introduction to Variable Refrigerant Systems
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How does VRF Operate? Electronic Expansion Valve (EEV) Control
EEV’s receive ‘PID’ control feedback to adjust refrigerant volume Up to 2000 steps of control Inlet Outlet PID Control Signal Valve Mechanism Continual management of flow rate controls super heat and coil capacity for optimum performance and energy efficiency 11/16/2010 NM ASHRAE – Introduction to Variable Refrigerant Systems
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How does VRF Operate? Proportional, Integral & Derivative (PID) CPU
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 T2 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. CPU (PID Control) T4 Controller (TSET) T1 11/16/2010 NM ASHRAE – Introduction to Variable Refrigerant Systems
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System Capacity Control
How does VRF Operate? T3 T4 T2 T1 Controller (TSET) CPU (PID Control) System Capacity Control EACH INDOOR CONTROLS ITS CAPACITY VIA PID CONTROL AND AN E.E.V. 1 2 3 4 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. CONDENSING UNIT ADJUST THE INVERTER COMPRESSOR TO PROVIDE THE REQUIRED CAPACITY (Large or Small) 11/16/2010 NM ASHRAE – Introduction to Variable Refrigerant Systems
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How does VRF Operate? DC Fan Motor Efficiency
Efficiency improved in all areas compared to conventional AC motors, especially at low speeds 70 80 90 100 10 20 30 40 50 60 110 Revolutions [rps] Motor Efficiency [%] DC Motor AC Fan Motor Magnet DC Fan Motor Approx. 40% increase 20% AC Motor 11/16/2010 NM ASHRAE – Introduction to Variable Refrigerant Systems
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NM ASHRAE – Introduction to Variable Refrigerant Systems
Agenda What is VRF? History Concept How does VRF Operate? Refrigerant Compressor Fan Coil Important Standards ASHRAE Standard 15 AHRI 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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Important Standards / Code Information
Overview of ASHRAE Std 15 Specifies minimum safety requirements in the event of a refrigerant leak into an occupied space. Safety Issues: Flammable refrigerants causing injury or death by fire. Toxic refrigerants possibly causing injury or death by poisoning. Non flammable and non toxic refrigerants causing injury or death by asphyxiation from oxygen displacement. 11/16/2010 NM ASHRAE – Introduction to Variable Refrigerant Systems
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Important Standards / Code Information
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 To the design, construction, test, installation, operation, and inspection of mechanical and absorption refrigeration systems, including heat pump systems used in stationary applications, To modifications including replacement of parts or components if they are not identical in function and capacity, and To substitutions of refrigerant having a different designation. 11/16/2010 NM ASHRAE – Introduction to Variable Refrigerant Systems
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Important Standards / Code Information
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 11/16/2010 NM ASHRAE – Introduction to Variable Refrigerant Systems
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Compliance Responsibilities
Important Standards / Code Information 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 11/16/2010 NM ASHRAE – Introduction to Variable Refrigerant Systems
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Current Situation Important Standards / Code Information
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 11/16/2010 NM ASHRAE – Introduction to Variable Refrigerant Systems
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Important Standards / Code Information
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
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AHRI-1230 Explanation of the Ratings
Important Standards / Code Information 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 11/16/2010 NM ASHRAE – Introduction to Variable Refrigerant Systems
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NM ASHRAE – Introduction to Variable Refrigerant Systems
Agenda What is VRF? History Concept How does VRF Operate? Refrigerant Compressor Fan Coil Important Standards ASHRAE Standard 15 AHRI 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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NM ASHRAE – Introduction to Variable Refrigerant Systems
VRF/VRV Benefits Outdoor Unit Indoor Units Main features Energy Saving Individual control Long refrigerant Piping Wide range of units Low Noise Level 11/16/2010 NM ASHRAE – Introduction to Variable Refrigerant Systems
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Users Comfort Accurate Temperature Control
VRF/VRV Benefits Users Comfort Accurate Temperature Control 30 25 20 15 10 40 50 60 70 Cooling mode with VRF System: Min.. Conventional A/C VRF system Room Temperature Down to 1F 11/16/2010 NM ASHRAE – Introduction to Variable Refrigerant Systems
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User Comfort Low Operating Sound
VRF/VRV Benefits User Comfort Low Operating Sound Ductless operating sound levels as low as 28dB(A) Ducted operating sound Levels as low as 35dB(A) 11/16/2010 NM ASHRAE – Introduction to Variable Refrigerant Systems
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Lightweight, Small & Flexible
VRF/VRV Benefits Lightweight, Small & Flexible Conventional System VRV 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 11/16/2010 NM ASHRAE – Introduction to Variable Refrigerant Systems
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NM ASHRAE – Introduction to Variable Refrigerant Systems
VRF/VRV Benefits Reduced Intallation Space For 10 Tons capacity Refrigerant R-410A Water Ø 1-1/8“ Ø 1/2“ Ø 2“ Ø 2“ Air 24“ 49“ Ø 25 ½“ Always two ducts needed 24“ 16“ or or 11/16/2010 NM ASHRAE – Introduction to Variable Refrigerant Systems
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Advanced Controls Solutions
VRF/VRV Benefits Advanced Controls Solutions ~ Ethernet (for use in Lon Works networks) BMS Fire alarm Security ~ HRV Power supply facility 11/16/2010 NM ASHRAE – Introduction to Variable Refrigerant Systems
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NM ASHRAE – Introduction to Variable Refrigerant Systems
Agenda What is VRF? History Concept How does VRF Operate? Refrigerant Compressor Fan Coil Important Standards ASHRAE Standard 15 AHRI 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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The Future of VRF in North America
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 11/16/2010 NM ASHRAE – Introduction to Variable Refrigerant Systems
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The Future of VRF in North America
What’s Next: Domestic and Hot Water Heating 11/16/2010 NM ASHRAE – Introduction to Variable Refrigerant Systems
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NM ASHRAE – Introduction to Variable Refrigerant Systems
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. 11/16/2010 NM ASHRAE – Introduction to Variable Refrigerant Systems
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Introduction to Variable Refrigerant Flow Systems
Thank You! Allen Anaya Application Consultant WM Carroll, LLC Ph: Cell: Fax: 11/16/2010 NM ASHRAE – Introduction to Variable Refrigerant Systems
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