This presentation discusses architect-engineer services for the master planning and design of a central utility facility (CUF) over a 10-year development period. It covers net zero energy definitions, case studies of net zero energy buildings including a university lab and air force hangar, strategies for achieving net zero energy through integrated design and renewable energy options, and lessons learned.

1. Architect-Engineer Services Master Planning and Design
for 10-year Development at Central Utility Facility (CUF)
Presentation for
Gulf Coast Green 2013
Net Zero Energy
Case Studies
Scott West
Mechanical Engineer
May 2, 2013

2. Best Practice
Jacobs is a Registered Provider with The American Institute of
Architects Continuing Education Systems (AIA/CES). Credit(s)
earned on completion of this program will be reported to AIA/CES for
AIA members. Certificates of Completion for both AIA members and
non-AIA members are available upon request.
This program is registered with AIA/CES for continuing professional
education. As such, it does not include content that may be deemed
or construed to be an approval or endorsement by the AIA of any
material of construction or any method or manner of handling, using,
distributing, or dealing in any material or product.
Questions related to specific materials, methods, and services will be
addressed at the conclusion of this presentation.

3. Course Description
• This session will focus on design and implementation of
net zero energy buildings and how they can be turned into
an operational reality. Achieving net zero energy buildings
is the adopted goal of the AIA 2030 commitment and is
often viewed as the standard for climate neutrality for new
buildings. Net zero energy buildings offer particular design
challenges but are possible in many circumstances with
current technology.

4. Learning Objectives
• Cover the various definitions of net zero energy and how they
apply to high performance projects
• Learn how integrative design can help achieve project energy
goals
• Review net zero energy case studies and share lessons learned
• Evaluate the economics of net zero energy building design and
construction

5. Why Are We Concerned With Net Zero Energy?
• Energy security
• Resource conservation
• Reduce operating cost
• Mitigating climate change
• Local environmental impact reduction
• Hedge against future energy price volatility

6. Recent Energy Legislation and Federal Leadership in
Green Building Practices
• EPAct 2005, EISA 2007, EO 13423, EO 13514, Federal Leadership in
High Performance and Sustainable Buildings
• EO 13514 from Oct. 2009 states in Section 2.g.i: “beginning in 2020
and thereafter, ensuring that all new Federal buildings that enter the
planning process are designed to achieve zero-net-energy by 2030”

7. DoD and DOE Partner Up
• In 2008 DoD and DOE launched initiative to support net zero
energy military installations
• Launched collaborative pilot of Marine Corps. base at Miramar
• NREL has helped out with NZEI guidance so far
• All US military branches addressing net zero energy to varying
degrees

8. AIA 2030 Challenge

9. ASHRAE Path to Net Zero Energy

10. Net Zero Energy Definition
Type Description
Net Zero Site Energy The boundary is the site and
the energy is measured
annually at the utility meters
Net Zero Source Energy The energy is valued at its
point of extraction (e.g. the
wellhead or the coal mine)
Net Zero Energy Cost The credits received on
exported energy equals the
amount of annual energy bills
from utilities
Net Zero Energy Emissions The emissions from fossil fuel
energy use are offset by
renewable energy fed into the
grid on an annual basis

11. NREL Paper Goes Into More Depth on Definition

12. Site-Source Energy Factors
• NREL – Source Energy & Emission Factors for Energy Use in
Buildings – June 2007

13. Net Zero Energy Definition
• Source versus site energy
• On-site combustion versus all electrical
• Treatment of off-site renewable energy
generation and carbon offsets
• Campus setting versus treatment of individual
buildings
• Treatment of embodied energy
• Division of responsibilities between owners,
tenants and utilities

14. Federal Net Zero Energy Definition for DoD

15. Case Studies

16. University of North Texas – Net Zero Lab

17. Green Design Features
• Mixed mode ventilation with solar chimney
• Rainwater harvesting
• Solar PV and thermal
• Ground source heat pumps
• Radiant underfloor heating
and cooling
• Energy recovery ventilation
• Daylighting

18. Architectural Floor Plan

19. Underfloor Piping Zone Layout

21. They Built It!

22. University of North Texas – Net Zero Lab

23. Little Rock Air Force Base – C-130J Fuels
Maintenance Hangar

24. C-130J: Super Hercules

25. Level 1 Layout

26. Level 2 Layout

27. C-130J Fuels Maintenance Hangar
• Net zero energy design definition
»Includes plug/process loads
»Based on site energy, gas use is okay if it is offset on a
per Btu basis
»Transportation energy use not accounted for
• Challenges
»FMH require high exhaust and make-up air flow rates
»90.1-2007 PRM requires an artificial cooling system in
the hangar (this has changed thankfully)
»Hangar infiltration is a big concern in heating season

28. YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
MAYBE
MAYBE
MAYBE
NO
NO
NO
YES
NO
ECM Table

29. Show Model Inputs for all Alternatives
Baseline (Appendix G)
Current Concept
Design
(Appendix G)
ZNE Proposed Design
(Both)
Construction Type
U-value (Btu/h-
ft2-F) SHGC
U-value
(Btu/h-ft2-F) SHGC
U-value
(Btu/h-ft2-F) SHGC
Wall-CMU 0.085 - 0.085 - 0.045 -
Wall - metal 0.085 - 0.085 - 0.0499 -
Roof 0.048 - 0.047 - 0.032 -
Lobby glazing 0.650 0.250 0.520 0.331 0.520 0.331
Translucent panels 0.650 0.250 0.140 0.190 0.050 0.150
Door -storefront 0.600 0.250 0.520 0.331 0.520 0.331
Door - Opaque 0.700 - 0.200 - 0.200 -
Door- non-swinging 1.450 - 1.450 - 1.450 -
Partition Wall 0.123 - 0.094 - 0.094 -
Space Classification
Cooling
SADB
Heating
SADB RH %
Admin Areas 76 68 50
Shops/Storage 76 68 50
Mech/Elect 85 55 50
Comms 75 75 50
Hangar Area (conditioned) 85 65 50
Hangar Area (unconditioned) 110 65 50

30. ECM Energy Savings
0 100 200 300 400 500 600 700
ECM
Energy Savings (MWh)
Solar Thermal
Alternate Ventilation Method
Ground Loop - VRF in central core
Solar Hot Water Heater
Hanger Door Decreased Infiltration
Biomass Furnace for Hangar Heating
Air-cooled VRF in Central Core
Overhangs on Kalwall Panels
Increased Insulation
Exterior Lighting LED's
LED fixtures in the Central core area
Standard Kalwall Daylighting
Kalwall Aerogel+Daylighting
LED lighting in Hanger
ECM Bar Charts

31. ECM LEED % Savings
-1.00 0.00 1.00 2.00 3.00 4.00 5.00 6.00
ECM
LEED Savings %
Solar Thermal
Alternate Ventilation Method
Ground Loop - VRF in central core
Solar Hot Water Heater
Hanger Door Decreased Infiltration
Biomass Furnace for Hangar Heating
Air-cooled VRF in Central Core
Overhangs on Kalwall Panels
Increased Insulation
Exterior Lighting LED's
LED fixtures in the Central core area
Standard Kalwall Daylighting
Kalwall Aerogel+Daylighting
LED lighting in Hanger
ECM Bar Charts

32. Be sure you know your project goals
Total Energy Use - Appendix G
Models
0
200
400
600
800
1,000
1,200
1,400
1,600
EnergyUse(MWh)
Current Concept Design
NZE Proposed Design
% Improvement over Baseline -
Appendix G Models
20
25
30
35
40
45
50
55
60
65
70
%Improvement
Current Concept Design
NZE Proposed Design

33. Annual Energy Costs - Appendix G Models
0
20,000
40,000
60,000
80,000
100,000
120,000
140,000
160,000
180,000
200,000
Baseline (Appendix
G)
Current Concept
Design (Appendix G)
NZE Proposed
Design (Appendix G)
EnergyCosts($)
Domestic Hot Water
Heating - Gas
Heating - Electric
Fan Equipment
Cooling Equipment
Process Loads
Lights
Presenting Overall Energy Results

34. Renewable Energy Options

35. Solar PV Array

36. Lessons Learned

37. Look for the Sweet Spot
• Delivers the ideal result
for clients’ pocket books,
the environment and
society
ECONOMY SOCIETY
ENVIRONMENT
Sustainable
Development
(the ‘sweet spot’)
Viable
Bearable
Equitable

38. Integrated (Integrative) Design Process

39. Conceptual Project Planning
Design
Team
City /
County
Building
Owner
Energy
Consultant
Building
Occupants
Cx
Agent
Project
Manager
Utility
Company
3rd Party
Engineers &
Inspectors
MEP
Engineers
Interior
Designer
Architect
Landscape
Architect
Sustainable design
is most effective
when applied at the
earliest stages of
design
The conceptual design
process is a
collaboration of several
disciplines that
effectively integrates all
aspects of site planning,
building design,
construction, operations
and maintenance
A Sustainability
(Eco) Charrette is an
intensive workshop in
which stakeholders
and experts come
together to address
project sustainability
issues
The Charrette should
result in unified
sustainability, design
and construction goals
for everyone to work
toward

40. A Sense of Place
• Integrate the building with its surroundings
• Apply the most economical options to achieve the desired result
(e.g. don’t install a wind turbine to look green that won’t be
running most of the time!)
• Passive solar design should not be skipped over but should be
balanced with functionality and aesthetics

41. NZE Hierarchy

42. NZE Design for Passive Measures
• There is an economical limit to insulation levels
(diminishing returns)
• Limiting solar heat gain through high
performance glazing or solar shading is
paramount (especially in Texas!)
• If your local climate is amenable to natural
ventilation, the architectural design should be
accomodating to it, we have the tools now!
• Good daylight design is an iterative process and
proper modeling time should be allotted

43. NZE Design for HVAC
• Variable refrigerant flow (VRF) – very cost-
effective now compared to traditional systems
• Geothermal
• Radiant heating/cooling
• Displacement ventilation (and sometimes UFAD)
• Energy recovery ventilation – decouple space
conditioning from ventilation load to improve
effectiveness and control
• Use LED lighting where you can and use lighting
controls wherever they will help, e.g. occupancy
and daylight sensing

44. NZE Design for Renewables
• Solar PV – Very “plug-and-play” but account for placement and
orientation, PPA is a popular vehicle for large installations, default
NZE equalizer
• Solar thermal – EISA 2007 requirement for federal buildings, usually a
no-brainer for NZE
• Transpired solar collectors – excellent for areas with simultaneous
sunshine and heating hours
• Biomass – difficult to beat as a high quality heat source
• Wind – often very cost-effective but hub height must be high enough,
very visible though
• Offshore wind and wave/current energy – good potential for coastal
areas

45. NZE for Designers
• Form follows function instead of function following
form, NZE is a performance target and deviating
from this principle can torpedo an otherwise
successful approach
• Integrated, coordinated approach: disciplines
should not work in isolation, design changes can
have effects all the way down the line
• Model energy use early and often
• Design with a “systems mentality”; like in nature all
building systems are somehow connected, e.g.
DHW on geothermal system, selection of material
reflectances affects daylighting, etc.

46. NZE for Building Users/Owners
• Plug/process loads become 40% or higher of overall
building energy use for NZE designs
• Occupant behavior’s effect on energy use becomes very
significant, behavioral change is often necessary
• Emphasis on flexibility rather than recipe approach: Might
have to revisit existing design standards and decisions in
order to achieve goal of NZE
• Suggest energy sub-metering, EMS and dash-boarding to
complete energy information feedback loop
• Expect to spend more time on conceptual design phases

47. Cost of Net Zero Energy
• Cost premium anywhere between 5% up to 25%
or even higher
• Emphasis on delivering NZE economically
• Rigorous life cycle costing is crucial
• Implementing passive energy measures can
often down-size HVAC equipment enough to
save significant costs
• Spend time on careful cost estimation at various
decision points: rules of thumb and $/sf
estimates don’t work very well for NZE

48. Net Zero Energy Economics
• How effective is the energy reduction measure compared
to PV?
• For the same amount of kWh saved from an ECM, how
does it compare to the cost of PV to generate the same
amount of kWh?
• This is often the cost inflection point between energy
efficiency and renewable energy

50. Thank you
Scott West, P.E.
Mechanical Engineer
scott.west@jacobs.com
T: 281.776.2507
Quest
ions

51. Bibliography
1. US Army Vision for Net Zero:
http://army-energy.hqda.pentagon.mil/netzero/
2. Architecture 2030 Challenge:
http://architecture2030.org/2030_challenge/the_2030_challenge
3. ASHRAE; Report of the Technology Council Ad Hoc Committee
on Energy Targets; June 2010
4. 7 Group, Bill Reed; The Integrative Design Guide to Green
Building; 2009