announcement about the final project presentations: thursday 8:00 – 10:45 am 16 presentations –...
TRANSCRIPT
Announcement about the final project presentations:
• Thursday 8:00 – 10:45 am• 16 presentations
– 5 minutes each +2 minutes for Q&A
• PowerPoint– Upload the file before the class
• Approximately 5-6 slides (a minute per slide)– Problem introduction – Model development - specific problem– Results – Results – Discussion / Summary
Presenter list(will send you by email today)
Thursday 9:30 am:
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Thursday 8:00 am:
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Lecture Objectives:• Moisture transport
– Point out similarity with heat transfer – Introduce the process and modeling software
• Finalize discussion about energy modeling – Application– Accuracy– Use in LEED certification process
• Course summary and Course evaluation
Moisture related problems
Moisture transport - fundamentals
However, you should be very carful how you use vapor barrier !Theory & application (on the whiteboard)
Moisture transfer software
• WUFI
• http://web.ornl.gov/sci/ees/etsd/btric/wufi/software.shtml
List of energy simulation tools • Office of Energy Efficiency & Renewable Energy (EERE)
– http://energy.gov/eere/efficiency
Building Energy Software Tools Directory
• http://apps1.eere.energy.gov/buildings/tools_directory/subjects.cfm/pagename=subjects/pagename_menu=whole_building_analysis/pagename_submenu=energy_simulation
Your modeling in• Excel• MATLAB• Scilab
– http://www.scilab.org/
Many other • Mathematica
– http://www.wolfram.com/mathematica/
• Mathcad– http://www.ptc.com/product/mathcad/
• Python– http://www.python.org/psf/
• EES – http://www.fchart.com/ees/
• …….
What are the reasons for energy simulations?
1) Building design improvement
2) System Development
3) Economic benefits
4) Budget planning
1) Energy Modeling for LEED Projects
The methodology described in ASHRAE 90.1–2004 (Appendix G), California Title 24–2005, and Oregon Energy Code 2005 involves the
generation of two energy models:
– one representing a baseline minimum-standard building and the
– other representing the proposed building with all its designed energy enhancements.
• ASHRAE Standard 90.1 “Energy Standard for Buildings Except Low-Rise Residential Buildings”
– posted in the course handouts, also UT library has all ASHRAE and ANSI standards http://www.lib.utexas.edu/indexes/titles.php?let=A
• Relevant LEED Documentation– ttp://www.usgbc.org/ShowFile.aspx?DocumentID=7795
– Software List http://www.usgbc.org/ShowFile.aspx?DocumentID=3478
DOE reference building that satisfy ASHRAE 90.1
• Sixteen climate zones
• Sixteen building types
• http://www1.eere.energy.gov/buildings/commercial_initiative/reference_buildings.html
• Models already built for use in EnergyPlus
2) System development
THERM: heat thermal bridge analysis
• Example: facade design tool
3) Economic benefitsLife Cycle Cost Analysis
Budget planning for existing buildings
1) Building design improvement
2) System Development
3) Economic benefits
4) Budget planning
Empirical model
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 900
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Q [t
on]
t [F]
Load vs. dry bulb temperature Measured for a building in Syracuse, NY
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 900
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Q=-11.33+1.2126*t
Q=-673.66+12.889*t
Q [t
on]
t [F]
8760
1i ii
ii
57 tif t889.1266.673
57 tif t126.133.11(Q
Model
8760
1i ii
ii
57 tif t889.1266.673
57 tif t126.133.11(Q
For average year use TMY2
=835890ton hour = 10.031 106 Btu
Building modeling software
Very powerful tool
Use it wisely!
Simulation SoftwareWrong IN Wrong OUT
but
We need sophisticated users more than sophisticated software
How to get more info about software (any software)
• Software documentation – http://apps1.eere.energy.gov/buildings/energyplus/energyplus_documentation.cfm
– …..
• Forums – http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/– ….
• Call developers – works primarily for non-free software
1. Identify basic building elements which affect building energy consumption and analyze the performance of these elements using energy conservation models.
2. Analyze the physics behind various numerical tools used for solving different heat transfer problems in building elements.
3. Use basic numerical methods for solving systems of linear and nonlinear equations.
4. Conduct building energy analysis using comprehensive computer simulation tools.
5. Evaluate the performance of building envelope and environmental systems considering energy consumption.
6. Perform parametric analysis to evaluate the effects of design choices and operational strategies of building systems on building energy use.
7. Use building simulations in life-cycle cost analyses for selection of energy-efficient building components.
Review Course Objectives