introduction to vrf

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John Chavez!Gunder & Associates, LLC!

SELLING AND APPLYING

VRF TECHNOLOGY

Began my career in 1986!

About me

24 years as a Mechanical Contractor!

NATE Certified!

Mini-Split Experience since 1995!

VRF Experience since 2007!

Currently: Technical Sales and Support!

My Customers are:!

End Users and Building Owners

Contractors

Distributors

Mechanical Engineers

Architects

Factory Sales Personnel

About me

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Todays Topics

! ! !1. What is VRF Technology?!

! ! !2. What are the Key System Features?!

! ! !3. How Do VRF Systems Work?!

! ! !4. Review of System Components!

! ! !5. Applications and Design!

! ! !6. Service and Maintenance!

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Introduction to VRF?

VARIABLE REFRIGERANT FLOW

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not your typical heat pump!

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Software !Driving !

Hardware!

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First Installation was 32 Years Ago!

>Two Million Installations! World Wide!

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Chapter 18. Variable Refrigerant Flow

Proven Technology

Mitsubishi Electric!LG Electronics!Daikin!Panasonic/Sanyo!Fujitsu!Hitachi!Carrier/Toshiba!

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Samsung!EMI/Enviromaster!

Midea!Gree!MHI!

Sharp!about 10 more….!

The PLAYERS


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Midea!Gree!MHI!


The PLAYERS


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Midea!Gree!MHI!


The PLAYERS

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What is VRF?

A system of singular or modular heat pumps !and indoor fan coils that are connected !

by a common system control and !a common set of refrigerant piping.!

!

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What is VRF?



!

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What is VRF?



!

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The refrigerant is passed through a series of !fan coils by means of variable speed

compressors and metered by an !electronic expansion valve (EEV) that !

regulates refrigerant flow to !accommodate the comfort set point !

for individual fan coils and zones!

What is VRF?

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!The variable speed compressor increases!

or decreases the system capacity to !satisfy the individual load requirements!

What is VRF?

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!The variable speed compressor increases!

or decreases the system capacity to !satisfy the individual load requirements!

What is VRF?

Personalized zoned comfort control

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!The software programming in the outdoor unit

continually scans about 250 data points to!meet specific tolerances in target temperatures

and pressures.!

What is VRF?

the software is a conductor in a sophisticated symphony

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Heat Pump vs. Heat Pump with Heat Recovery

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Heat Pump vs. Heat Pump with Heat Recovery

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Heat Pump

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Heat Pump

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Heat Pump

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Heat Recovery Simultaneous Heating and Cooling

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Simultaneous Heating and Cooling

Heat Recovery

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Simultaneous Heating and Cooling

Heat Recovery

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Common Network Refrigerant Circuit and Control Communication Buss

32 What are the Key Features?

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Mix and Match Indoor Units!

Inverter Driven Scroll Compressors!

Up to 150% Connected Capacity!

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Flexibility in Design!

Zoned Space Control!

Simultaneous Heating and Cooling!

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Two or Three Pipe System!

Two Wire DDC Network!

Integrated Controls Network!

BACnet and LonWorks!

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Diversity!Building

Load Profile

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Distributed Capacity!

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Flexible Piping Design

3280 FT

295 FT 49 FT

295 FT 540 FT

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8 inches Tall

80 Tons

Economy of Scale

Economy of Scale

Fits into a Six Person Elevator

Air 30” Diameter

Ductwork

Water 2 1/2” Iron Pipe

2” Iron Pipe

Refrigerant R410A 1 1/8” Copper Pipe

Space required to deliver 20 tons of cooling

Economy of Scale

Air .3 Watts/kg

Water 5.8 Watts/kg

Refrigerant R410A 57 Watts/kg

Economy of Scale

Air .3 Watts/kg

Water 5.8 Watts/kg

Refrigerant R410A 57 Watts/kg

Economy of Scale

Transporting expensively generated conditioned air Is probably not the best method to heat and cool a building

Refrigerant has 10x the heat transfer capacity of chilled water and 190x that of air

Ceiling Space

Economy of Scale

Integrated Controls

Low Sound Rating

VRF Heat Pump

VRF Indoor Units

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System Automatically Matches the Zone Load

Adjusts the Flow of Refrigerant and Energy

Adjusts the Compressor Speed and Fan Speed

Improves Temperature Control

Energy Efficient

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off the charts energy efficiency when in part load conditions

Inverter driven compressor matches compressor speed to meet the full or part load demand

soft starts no lock rotor amps

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allows for precise temperature and humidity control

Room Temperature

Set Point 75F

60Hz

Compressor

0Hz

150Hz

30Hz

Room temperature is steady.

High rotation speed up to 120Hz

Keeps rotation speed low after temperature stabilizes.

adjusts rotation speed precisely keeps steady space temperature

80F

ON Very Efficient

Comfortable! Very fast!

Load Matching Refrigerant Flow

“soft start” Low Current at start

Lower Electrical Loads

Lower Architectural Costs

Lower Structural Costs

Total Building First Costs

Typical HVAC Efficiency Ratings

rating systems are based at part load capacity

•  IEER – Integrated Energy Efficiency Rating = Took the place of IPLV, is used for VRF product, and is explained in detail on the next slide

•  SCHE – Simultaneous Cooling & Heating Efficiency = the efficiency of VRF Heat Recovery at simultaneous 50% heating & 50% cooling

Schematic Design Phase System Benefits

Federal Guidelines-AHRI Standard 1230

!Establishes Testing Procedures""

""! "

"

!VRF Efficiency Database ""

"! "

"

!Part-Load Efficiencies""

"! "

"

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If installed correctly,!VRF systems are bullet proof.!

!-Large Texas Based Commercial Contractor!

“ ”

.05% (Five Hundredths of One Percent) Warranty Return

Reliability

Lower Life Cycle

Lower Life Cycle

the cost of an hvac system is about more than the cost of design, equipment and installation.

you need to consider operation, service, maintenance and replacement in the total cost equation.

VRF zoning systems are more efficient, easier to design, takes less time to install and require significantly less maintenance than conventional hvac systems.

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How Do VRF Systems Work?

LEV Coil Inet

Coil Outlet

Constantly monitoring to keep a target

Superheat or Subcooling Temperature

Return Air Stream Sensor

SMART COIL

or Room Space Sensor

LEV Coil Inlet

Coil Outlet

Constantly monitoring to keep a TARGET

Superheat or Subcooling Temperature

Return Air Stream Sensor or Room Space Sensor

SMART COIL

SMART COIL

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2000 Steps

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Two vs Three Pipe Heat Recovery Systems

Inverter+Fixed or Inverter Only

Service Access to Components

Controls Network

Piping Rules

Programming Logic

DIFFERENCES IN VRF SYSTEMS

Capacities at Low Ambient Conditions

Defrost Strategy

Oil Management

Customer Support/Training

Service Software Tools

Selection Software Tools

Information Available to the Public

DIFFERENCES IN VRF SYSTEMS

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Review of System Components

Air and Water Source Heat Pumps DOAS ERV Indoor Fan Coils Zone Control Central Control

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Air and Water Source Heat Pumps

94 Models

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Heat Recovery !Heat Pump with Branch Controller!

6~28 Tons!208~230, 460 Volt!

Inverter Driven Scroll Compressor!Sound Rating as Low as 48 dB’s!

Outdoor Units

Connect 50:1!Connect up to 150%!

LG = Heat Recovery Unit

Branch Circuit Controller

Daikin = Branch Selector

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Three Phase Heat Pump!

6~36 Tons!208~230, 460 Volt!

Inverter Driven Scroll Compressor!Sound Rating as Low as 48 dB’s!

Connect 50:1!Connect up to 130%!

Outdoor Units

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3,4, & 5 Tons!208~230 Volt, Single Phase!

Inverter Driven Scroll Compressor!

Sound Rating as Low as 49 dB!

Single Phase Heat Pump!

Connect up to 130%!Connect 8:1!

Outdoor Units

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Indoor Units

11 Styles and 64 Models

Space Mounted Units

High Wall Mounted Ceiling Suspended

Floor Standing (PFFY-NRMU for recessed mounting not shown)

CITY MULTI VRF

Four Way 33x33 Ceiling Cassette Four Way 24x24 Ceiling Cassette

One Way Cassette

CITY MULTI VRF

Ceiling Recessed Cassettes

Concealed Ducted Units

Ceiling Concealed Medium Static Up to .6 In W.C. High Static up to 1 In W.C. Low Profile Up to .2 In W.C.

Fan Coil Down/Horizontal Left/ Vertical Ducted

Product Review CITY MULTI VRF

Integrated Digital Control System •  2 Wire DDC System

–  16 GA. Stranded & Shielded

–  Daisy Chain Connection

–  Non-Polarized

•  Customizable Control Scheme

•  Integration into BMS & EMS

•  Third Party Equipment Control

Controls Network

Controls Network

Zone Control

Central System Control

PC-Based Controls Web Browser Functionality

Product Review CITY MULTI VRF

Controls Network

CITY MULTI VRF

iPhone, iPad, iTouch App

Controls Network

IN

P1 P2 F1 F2 P1 P2 F1 F2 P1 P2 F1 F2

P1 P2 F1 F2 P1 P2 P1 P2

Zone 1

Zone 2

Zone 3

Typical Controls Wiring

System Design

Selection Software

• Easy to Use • Drag & Drop System Components

• Input Project Information

• Output Layout and System Design

Selection Software

Document Design Phase System Design

AutoCAD Output AutoCAD

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Target Applications!

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College Dormitory!

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Churches!

Hotels!

Hospitals!

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Reduced Electrical Panel from 5kVA to 2kVA!

Dallas, Texas!The Element Hotel!

System is Activate by a Key Card!

107 Waco, Texas!

Roosevelt Tower!12-Story Luxury Office Building!

108 Oklahoma City, OK!

SandRidge Energy!30-Story Office Building!

Location of CDU

217 ft

167 ft

How to overcome

higher level

difference

384 ft

CDU on Upper Roof

217 ft

167 ft

1454 Tons

CDU on Lower Roof

217 ft

167 ft 1259 Tons

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[ Custom Home ]!

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Service And Maintenance

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Just wash or replace the air filters and clean the coils with fresh water. That’s it!!

Maintenance

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The number one thing you need when!troubleshooting a VRF or DFS system is…….!

Service

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DC Voltmeter!Selectable!

Range up to!500k Ohm!

Ohm-meter!

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VRF Systems are changing the way we Heat and Cool buildings

http://www.linkedin.com/in/johnkchavez!

Contact me

[email protected]!

Open Forum 128

introduction to vrf

Engineering