high performance hvac - new buildings...
TRANSCRIPT
Terry EgnorSenior Consultant
NBI
High Performance HVACFor Small to Medium Commercial
Integrated Energy DesignConventional System
2. Optimize System
© 2006 Energy Studies in Buildings Laboratory, University of Oregon, and Konstrukt
1. Reduce Loads
Loads Cut 50% and Double System Efficiencysystem cost energy cost
ABSIC / CBPD Guidelines for High Performance HVAC
1. Separate ventilation systems from thermal conditioning2. Design for natural ventilation with mixed-mode conditioning3. Provide task conditioning and individual control4. Design for continuous change with plug and play HVAC & controls5. Design architecture ‘unplugged” for maximum efficiency and passive design6. Engineer load balancing7. Engineer energy and material effective HVAC systems with ‘energy cascades’8. Create distributed, communicating, modifiable automation systems9. Innovative HVAC system integration for thermal and air quality, resource conservation & environmental health.Advanced Building Systems Integration Consortium / Center for Building Performance and Diagnostics – Carnegie Mellon University
Incorporate Passive Technologies
UC Davis Veterinary Medicine
•Natural ventilation•Thermal mass•Night venting•Daylighting
•Economizers•Site shading•Building orientation•Ground coupling•Expanded Comfort Range
Energy Savings Potential Summary for 15 Technology Options
Technology Option Technology
StatusSavings Potential
(quads)Adaptive/Fuzzy Logic Controls New 0.23Dedicated Outdoor Air Systems Current 0.45Displacement Ventilation Current 0.20Electronically Commutated Permanent Magnet Motors Current 0.15Enthalpy/Energy Recovery Heat Exchangers for Ventilation Current 0.55Heat Pumps for Cold Climates (Zero-Degree Heat Pump) Advanced 0.10Improved Duct Sealing Current 0.23Liquid Desiccant Air Conditioners Advanced 0.2/.06Microenvironments / Occupancy-Based Current 0.07Microchannel Heat Exchanger New 0.11Novel Cool Storage Current 0.2/0.03Radiant Ceiling Cooling / Chilled Beam Current 0.60Smaller Centrifugal Compressors Advanced 0.15System/Component Diagnostics New 0.45Variable Refrigerant Volume/Flow Current 0.30
0 10 20 30 40 50 60 70 80 90 100
Daylighting
Controls
Increased Insulation
HVAC Efficiency
Natural Ventilation
Heat Recovery
Applied PV
Glazing Performance
Demonstration PV
UFAD/Displacement
GSHP
VFDs
Technologies in GT50
Current Favorites
Air Systems• Natural or Hybrid DOAS• Night venting• Energy Recovery Systems• Displacement Ventilation• Under Floor Air Delivery • Evaporative cooling, direct & indirect
Current Favorites
Non-air Systems• Ground/water source heat pumps• Variable refrigerant flow DX systems• Condensing boilers• Chilled beams• Radiant surface heating/cooling
Indirect Evaporative Cooling
Indirect Evaporative Cooling
Adjustable Speed Drives
18%
40%
ASD = VFD = VSD
• Fans and pumps serving variable flows with 1+ motor horsepower should use adjustable speed drives
- 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36
Natural Ventilation
Indirect Evaporative Cooling
Natural Ventilation with ThermalMass
Radiant Cooling
Displacement Ventilation
Ducted Variable Air Volume
Peak Cooling Load, Btu/hr-SF
Peak Cooling Load, SF/ton 2,000 1,000 500 333
The dark blue bands represent typical peak cooling load thresholds for various system concepts. Peak loads above the end of the light blue bars will be challenging to meet with the various system types.
Courtesy of Solarc A&E
Synergy: Loads and Cooling Systems
0
50
100
150
200
250
300
350
400
450
500
MBH
Courtesy of Solarc A&E
Variable Volume Reheat System - Boise
What is Causing the Heating Load?
0
50
100
150
200
250
300
350
400
450
500
MBH
Courtesy of Solarc A&E
Variable Volume Reheat System - Boise
What is Causing the Heating Load?
0
2
4
6
8
10
12
14
16
Tons
Courtesy of Solarc A&E
Variable Volume Reheat System - Boise
What is Causing the Cooling Load?
0
2
4
6
8
10
12
14
16
Tons
Courtesy of Solarc A&E
Variable Volume Reheat System - Boise
What is Causing the Cooling Load?
0
10,000
20,000
30,000
40,000
50,000
60,000
70,000
80,000
90,000
100,000
Code/Boise
EUI (
Btu/
SF-y
ear)
Exterior Lighting
Service Water Heating
Fans and Pumps
Space Cooling
Space Heating
Misc. Elect. Equipment
Lighting
70,212
2030 Challenge Target: 50% of base: 36,000
Net Zero Energy Target: 12,000 to 20,500
1: Space Heating
2: Lighting
3: Misc. Equip
4: Fans & Pumps
5: Cooling
Courtesy of Solarc A&E
Where is Energy Used?Lets start with a “Code Building”
0
10,000
20,000
30,000
40,000
50,000
60,000
70,000
80,000
90,000
100,000
Code/Boise Initial EnvelopeSet
Internal Loads Systems Solar
EUI (
Btu
/SF-
year
)
Exterior Lighting
Service Water Heating
Fans and Pumps
Space Cooling
Space Heating
Misc. Elect. Equipment
Lighting
70,212
Net Zero Energy Target: 12,000 to 20,500
2030 Challenge Target: 50% of base: 35,100
59,230 (15% reduction)
51,086 (27% reduction)
32,945 (53% reduction)
27,611 (61% reduction)
Courtesy of Solarc A&E
Synergy: Integrated Energy Design Performance
0 20 40 60 80 100
VAV
Economizer
EMS
Energy Audit
VSDs
Occupancy SensorsTe
chno
logy
Percent of Buildings
CBECS worst 25%Energy StarCBECS Average
Technology = Performance
• Commissioning• Monitoring• Peak Shedding• Operations Guide• Maintenance/Replacement• Occupant Behavior
Operations Strategies
What are the Boundaries?
IAQ is governed byASHRAE Standard 62.1 - 2007
Comfort is governed byASHRAE Standard 55 - 2004
Occupant Expectations: Thermal Comfort Design Criteria
Energy Studies in Buildings Laboratory University of Oregon
Seasonally Adjusted Comfort
Occupant Expectations: IlluminanceDesign Criteria
Energy Studies in Buildings Laboratory University of Oregon
• An integrated design process is critical for success at this performance level
• The technology is available and steadily improving
• Systems integration and enhanced control are essential
• Occupant involvement is needed• Measured performance is where the
rubber meets the road
Summary