Variable Refrigerant Flowe3tnw.org/portals/0/E3TFiles/Showcase4-VRF_14Nov2012_FINAL.pdf · Jack...

E m e r g i n g Te c h n o l o g i e s S h o w c a s e November 14, 2012

E3T Energy

Efficiency

Emerging Technologies

Welcome. Today’s webinar is being recorded and will be posted within days to:

• www.E3Tnw.org

• www.ConduitNW.org

If you have any questions during the presentation, please submit them to us through either the Chat or Q&A windows on your screen. We’ll go over these questions during the Q&A at the end of today’s session.

The webinar will begin momentarily. Thank you for attending!

Variable Refrigerant Flow

http://www.e3tnw.org/

http://www.conduitnw.org/

E m e r g i n g Te c h n o l o g i e s S h o w c a s e

Jack Zeiger, CEM

Marcia Karr, PE November 14, 2012 S p o n s o r e d b y B P A ’ s E 3 T P r o g r a m

E3T Energy

Efficiency



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Efficiency


Variable Refrigerant Flow (VRF)

• Overview

How VRF works

How VRF is different

• Benefits

• Challenges

• BPA ET field test

• Case studies

Lewis County PUD

Pacific University Burlingham Hall

Little Deschutes Lodge

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Evolution of VRF

Japan 25+ Years

Europe 20+ Years

Latin America 15+ Years

Bermuda 15+ Years

USA 10+ Years

(97% of market)

(3% of market)

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Efficiency


What is VRF?

• Heat pump (changeover)

All heating or all cooling to zones at a time

• Heat recovery

Heating and cooling simultaneously to multiple zones

Requires more controls and equipment, and costs more

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VRF Efficiency Features

• Variable speed compressor and fans on outdoor unit

• Variable speed indoor unit fans

• Linear (variable) expansion valve

• Piping system in place of ductwork

• Refrigerant used directly for heat transfer

• Ventilation – usually a dedicated outside air system

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How is VRF Different?

• Adjust cooling and heating by adjusting refrigerant flow and variable speed compressor

• Serves multiple zones from one outdoor unit

• Indoor units can be in different modes

Called heat recovery

• Backup heat is not usually necessary in the NW (or even in Montana!)

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VRF with Heat Recovery

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VRF Benefits

• Overall more energy efficient

• Improved temperature (comfort) control

• Very good low-temperature heating performance

• Quiet performance

• Design flexibility

• Lighter-weight equipment, smaller footprint

• Compressor operates at actual load, not peak

continued

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VRF Benefits

• Heat recovery among zones

• Greater submetering capability

• Allows above-ceiling height to be reduced

• Smaller power distribution system

• Conducive to retrofits

• Longer compressor life – soft start, variable speeds

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VRF Challenges

• Higher first cost (not always)

• Refrigerant safety issues (easily solvable)

• Need dedicated outside air system

• Replacement part availability and cost

• Lack of expertise and experience in NW (getting better)

• No air-side economizer (some jurisdictions)

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Equipment Component Options

+ + Branch Circuit

Controller +

Indoor

Units

Control

System Outdoor

Units

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Efficiency


Zonal Temperature Control

Conventional HVAC

Time

Ro

om

Te

mp

era

ture

VRF

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Controls Network

• BMS integration controls,

LonWorks® or BACnet®

• PC-based control via web

browsers or software

• Centralized control

• Individual zone control

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Water-Source Heat Recovery System

Water-source units BC

controller

Indoor units

Water circuit

Indoor units Heat recovery

Heat recovery

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Efficiency


Domestic Hot Water and Boiler Unit

Booster unit

• Heats water to 160oF

Hot/chilled water unit

• Heats water to 113oF

• Cools water to 50oF

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Efficiency


VRF Summary

• VRF can reduce HVAC energy consumption up to 40 percent over the current code minimum efficiency,

Depends on location and application

• Ground source system is more efficient in extreme climates

• Fan energy savings:

Ductless capability

VRF operates at ~300 cfm/ton vs ~400 cfm/ton for traditional HVAC

continued

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Efficiency


VRF Summary

• High part-load efficiency per AHRI 1230 (IEER)

• Internal/external heat recovery

• Current energy model software underestimates energy savings

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Regional Technical Forum

• Variable capacity heat pump subcommittee

Includes VRF

• Has been meeting for a year

• Developed roadmap

• Developing deemed calculator

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BPA/EPRI Lab Testing

• Developing performance maps for Mitsubishi, Daikin, and LG

• For use in building modeling software

• Should lead to more accurate modeling.

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BPA VRF System ET Field Test

• Purpose

Develop method to verify efficiency of energy use by VRF systems

• Limits

First 10 VRF systems

Deadline November 30, 2012 (may be extended)

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BPA Field Test Participation Request

Participation Request Form https://docs.google.com/spreadsheet/viewform?formkey=dEhRSjBPdmg3VVp6NVdsSDBZV0VIeFE6MA#gid=0 Details http://www.bpa.gov/energy/n/emerging_technology/pdf/e3t_participationdoc_VRF.pdf VRF Resource Page http://www.bpa.gov/energy/n/emerging_technology/VRFFieldTest.cfm

http://www.bpa.gov/energy/n/emerging_technology/pdf/e3t_participationdoc_VRF.pdf

https://docs.google.com/spreadsheet/viewform?formkey=dEhRSjBPdmg3VVp6NVdsSDBZV0VIeFE6MA
















http://www.bpa.gov/energy/n/emerging_technology/VRFFieldTest.cfm

http://www.bpa.gov/energy/n/emerging_technology/VRFFieldTest.cfm

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Case Study #1

Two-story, 23,700 square foot office building

Built in the 1940s

LEWIS COUNTY PUD (RICE GROUP, INC.)

CHEHALIS, WASHINGTON

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Lewis County PUD

VRF installed to:

• Increase zoning for better comfort

• Allow building to remain occupied during construction

• Allow phased installation

• Reduce carbon footprint

• Keep hard ceilings intact

• Provide simple control system

• Existing supply/return duct for dedicated outdoor air system (DOAS) with a heat recovery unit

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Lewis County PUD

Design considerations

• Condensate drainage

• Submetering capability

Comments

• Occupants very happy with increased comfort and control

• Very quiet system

• Control system simple and easy to operate

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Lewis County PUD

EPRI | Electric Power Resource Institute

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Case Study #2

PACIFIC UNIVERSITY, BURLINGHAM HALL FOREST GROVE, OREGON

49-unit dorm, 59,000 square feet

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Pacific University, Burlingham Hall

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Pacific University, Burlingham Hall

Benefits

• Uses 33.5 percent fewer kilowatt-hours than modeled in the baseline

• Uses 28.9 percent fewer kWh than expected

• Electricity costs are $11,600/year less than forecasted

• Works well with historical campus architecture

• Structural and architectural advantages

• No additional backup heat required

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Case Study #3

LITTLE DESCHUTES LODGE LA PINE, OREGON

26-unit complex

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City Air-Source Heat Pump

(HP)1 Ground-Source HP2 VRF (air-source) Ground-Source VRF HP

kBtu kBtu % Savings kBtu % Savings kBtu % Savings

Billings 65.3 46.0 30% 46.2 29% 42.5 35%

Phoenix 65.9 51.8 21% 45.5 31% 40.9 38%

Denver 59.5 44.3 26% 41.5 30% 40.4 32%

Kansas City 73.5 49.3 33% 46.2 37% 43.5 41%

Seattle 54.9 43.9 20% 34.7 37% 34.6 37%

Portland 56.5 44.6 21% 36.0 36% 35.3 38%

1 EER = 10.0, Seasonal Energy Efficiency Ratio (SEER) = 13.0, Heating Season Performance Factor (HSPF) = 5.0

Air-source heat pumps are commonly used in assisted living facilities, hotels, etc. 2 EER = 15.7, Coefficient of Performance (COP) = 3.3

Annual Energy Use (kBtu/sf/yr) and Percent Savings Compared to Air-Source Heat Pump

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• 26-unit complex, on-site laundry, community room, reading room, two computer centers

• Gas and electric = $37/month per occupant

• EUI = 29 KBtu/sf (national average = 70 KBtu/sf)

• 28 horizontal trenches, 150 feet long

• 600 feet of 1-inch pipe per trench

• Four 8-ton VRF water-source heat pump

• Cost-effective for HUD affordable housing owners

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Benefits • Extreme temperatures – winter and summer • Ground source more beneficial than air source • HUD – rental fees constrained

Utility cost more cost-effective with VRF

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Questions?

For technology questions,

Marcia Karr Jack Zeiger [email protected] [email protected]

For BPA Field Test questions,

Mira Vowles [email protected]

mailto:[email protected]



E3T Energy

Efficiency


Next Webinar

Emerging Technologies Showcase

Residential Smart Thermostats

Wednesday, December 19, 2012

12:00 noon to 1:00 p.m. Pacific time

More information about emerging technologies:

E3T database: www.E3Tnw.org

E3T Program: www.bpa.gov/energy/n/emerging_technology/

Conduit: www.ConduitNW.org

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