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
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Variable Refrigerant Flow
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
Emerging Technologies
Variable Refrigerant Flow
E3T Energy
Efficiency
Emerging Technologies
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
E3T Energy
Efficiency
Emerging Technologies
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)
E3T Energy
Efficiency
Emerging Technologies
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
E3T Energy
Efficiency
Emerging Technologies
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
E3T Energy
Efficiency
Emerging Technologies
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!)
E3T Energy
Efficiency
Emerging Technologies
Variable Refrigerant Flow
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Efficiency
Emerging Technologies
VRF with Heat Recovery
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Efficiency
Emerging Technologies
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
E3T Energy
Efficiency
Emerging Technologies
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
E3T Energy
Efficiency
Emerging Technologies
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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Efficiency
Emerging Technologies
Equipment Component Options
+ + Branch Circuit
Controller +
Indoor
Units
Control
System Outdoor
Units
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Efficiency
Emerging Technologies
Zonal Temperature Control
Conventional HVAC
Time
Ro
om
Te
mp
era
ture
VRF
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Efficiency
Emerging Technologies
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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Efficiency
Emerging Technologies
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
Emerging Technologies
Domestic Hot Water and Boiler Unit
Booster unit
• Heats water to 160oF
Hot/chilled water unit
• Heats water to 113oF
• Cools water to 50oF
E3T Energy
Efficiency
Emerging Technologies
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
E3T Energy
Efficiency
Emerging Technologies
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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Efficiency
Emerging Technologies
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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Efficiency
Emerging Technologies
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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Efficiency
Emerging Technologies
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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Efficiency
Emerging Technologies
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
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Efficiency
Emerging Technologies
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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Efficiency
Emerging Technologies
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
E3T Energy
Efficiency
Emerging Technologies
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
E3T Energy
Efficiency
Emerging Technologies
Lewis County PUD
EPRI | Electric Power Resource Institute
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Efficiency
Emerging Technologies
Case Study #2
PACIFIC UNIVERSITY, BURLINGHAM HALL FOREST GROVE, OREGON
49-unit dorm, 59,000 square feet
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Efficiency
Emerging Technologies
Pacific University, Burlingham Hall
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Efficiency
Emerging Technologies
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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Efficiency
Emerging Technologies
Case Study #3
LITTLE DESCHUTES LODGE LA PINE, OREGON
26-unit complex
E3T Energy
Efficiency
Emerging Technologies
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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Efficiency
Emerging Technologies
Little Deschutes Lodge
• 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
E3T Energy
Efficiency
Emerging Technologies
Little Deschutes Lodge
Benefits • Extreme temperatures – winter and summer • Ground source more beneficial than air source • HUD – rental fees constrained
Utility cost more cost-effective with VRF
E3T Energy
Efficiency
Emerging Technologies
Questions?
For technology questions,
Marcia Karr Jack Zeiger [email protected] [email protected]
For BPA Field Test questions,
Mira Vowles [email protected]
E3T Energy
Efficiency
Emerging Technologies
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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