Today’s Webcast starts at 1:00 p.m. Eastern.

You will not hear audio until the Webcast begins

Today's Moderator

Dave Lubach Associate Editor

Facility Maintenance Decisions

Today's Presenter

Meghan Quinn, PE

Senior Associate, Syska Hennessy

Meghan Quinn is a Senior Associate of Syska Hennessy Group, Inc. and Supervising Engineer in the Los Angeles office. With more than 13 years of specialized professional engineering and design experience, Meghan is acknowledged as a client asset through her work on high-profile projects: Columbia Square in Hollywood, CA and The Huntington Botanical Gardens Entrance Complex in San Marino, CA. Recognized as an innovative mechanical engineer, Meghan offers comprehensive insights of the industry and leverages her experience to deliver a quality product that eases the client experience. Meghan holds a Bachelor of Science with a focus on mechanical engineering from University of Connecticut. She is a registered Professional Engineer in California, published author and presenter.

Learning Objectives:

• Review VRF technology and features

• Analyze the differences between air- and water-cooled VRF units

• Understand the impact of ASHRAE 62.1 on VRF specification and installation

• Discuss how to specify VRF units according to building features and use

To ask questions: Please use the question and answer panel on the right-hand side of the

screen, and send to all panelists.

Polling Questions Todays webcast will include multiple choice polling questions. Your

participation is appreciated.

Presentation Handouts All participants will receive an e-mail by the end of the day with a link to

download a PDF copy of today’s presentation slides.

CEU Information

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To successfully earn 0.1 CEUs, you must attend the entire webcast and earn a 70% or higher on the assessment.

VRF Technology Presented by Meghan Quinn, PE

9/27/16

• VRF/VRV

What is VRF?

Variable Refrigerant Flow (Volume)

Heat Pump vs. Heat Recovery

Air Cooled vs. Water Cooled

9/27/16

VRF Components

Condensing Unit

Ceiling Register FCU

Wall Mounted FCU Ducted FCU

Selector Box

Refrigerant Piping

9/27/16

• VRF Pros and Cons

• Pros:

Zoning/Temperature Control

Energy Savings

Acoustics

Water Conservation (Air Cooled)

• Cons:

Not the “Traditional” HVAC Solution

High quantity of refrigerant in system

Building height limitations

Restrictions with core shell/TI designs

9/27/16

• Zone/Temperature Control

9/27/16

• Benefit - Energy Savings

• High Efficiency

• Lower Pump Energy

• Heat Recovery

• Energy Recovery Ventilator

9/27/16

Heating only or Cooling only – All Zones Same Mode

Heat Pump

Cooling

Cooling

Cooling

Cooling

9/27/16

Synchronous cooling and heating in different zones

Cooling Heating

Cooling Heating

Heat Recovery

9/27/16

Outdoor Air

Indoor Air

Supply Air Exhaust Air

Energy Recovery Ventilator

9/27/16

• VRF Considerations in Building Design

Ventilation Strategies

Component location – piping restrictions

Location of Equipment

Core & Shell vs. TI

9/27/16

OSA Unit

SA SA

Delivered Adjacent

to the Fan Coil Unit

Delivered Directly

to the Fan Coil Unit

Delivered Directly

to the Zone

• Ventilation Strategies

9/27/16

Piping Limits

• Total elevation

• Maximum separation between indoor units

• Maximum distance between first branch and farthest indoor unit

• Total piping length

Piping Installation

• Insulate piping

• Piping installed level

• Refrigerant Piping

9/27/16

• Refrigerant Piping – ASHRAE 15

Step 1: Calculate Total lbs of Refrigerant

Largest Circuit – Not sum of all circuits

Each type of Refrigerant

Step 2: Calculate Space Volume for Dilution

Volume of Smallest occupied space

Include plenums, rooms, corridors if permanently connected

Step 3: Compare to RCL

9/27/16

• Step 3 – Compare lbs/1000 ft3

R-410a - ASHRAE Standard 34-2013: RCL = 26 lbs/1000 ft3

What if Charge exceeds RCL?!…

Reduce refrigerant or dilute by increasing space volume

9/27/16

Polling Questions Todays webcast will include multiple choice polling questions.

Please make your selections to the right of this screen.

• Air Cooled vs. Water Cooled

Air Cooled VRF

Uses the Atmosphere

Needs no water

Restrictions on piping limits

Water Cooled VRF

Uses water as heat transfer medium

Ancillary Equipment needs higher pressure rating

Condensing units can be located inside

9/27/16

Air Source system Water Source system

Air Cooled vs. Water Cooled

9/27/16

Water Cooled Applications

Multi V Outdoor Unit

Mid temperature

High temperature

Indoor Unit Hot Water

Storage Tank

9/27/16

• Locating Equipment – Air Cooled

Exterior Units

Condenser Units

OSA Units

Interior Units

Branch Selector Boxes (BSB’s, BCB’s, etc)

Fan Coil Units

9/27/16

• Locating Equipment – Water Cooled

Exterior Units

Cooling Tower

Boiler

OSA Units

Interior Units

Branch Selector Boxes (BSB’s, BCB’s, etc)

Fan Coil Units

Condensing Units (if water cooled)

9/27/16

• VRF Applications

Large Offices

High Rise Residential

Core & Shell – TI Fit-outs

9/27/16

Large Office Buildings

• Interior & Exterior zones

• Individualized zones/comfort

• Tenant fit-out post construction

9/27/16

High Rise Buildings

• Limited roof space

• Modular equipment

• Multiple tenants

• Tenant fit-out post construction

9/27/16

Installed - Condenser Farm

9/27/16

Installed - Refrigerant Piping

9/27/16

• Lessons Learned

Specifying Units

Manufacturer Differences

Warranty Lengths

Energy Modeling

Metering

9/27/16

QUESTIONS?

9/27/16