high performance hvac - new buildings...

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