Final project presentation

• Thursday 8 – 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:

……..……

Thursday 8:00 am:

……..……

Lecture Objectives:

• Finalize discussion about energy modeling – Application– Accuracy– Use in LEED certification process

• Course summary and Course evaluation

ES programs(specific)

Window / Thermhttp://windows.lbl.gov/software/NFRC/NFRCSim6.3-2010-Cover-Chptr01.pdf

http://apps1.eere.energy.gov/buildings/tools_directory/software.cfm/ID=362/pagename=alpha_list_sub

WUFI-ORNL/IBP

Your models 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/

• …….

How to evaluate the whole building simulation tools

Two options:

1) Comparison with the experimental data - monitoring

- very expensive- feasible only for smaller buildings

2) Comparison with other energy simulation programs- for the same input data

- system of numerical experiments - BESTEST

Comparison with measured data

Cranfield test rooms (from Lomas et al 1994a)

BESTEST Building Energy Simulation TEST

• System of tests (~ 40 cases) - Each test emphasizes certain phenomena like

external (internal) convection, radiation, ground contact

- Simple geometry- Mountain climate

6 m

2.7 m

3 m

8 m

0.2 m

0.2 m

1 m

2 m

S

N

E

W

COMPARE THE RESULTS

Example of best test comparison

BESTEST test cases

0

2000

4000

6000

8000

10000

12000

195 200 220 230 240 270

Annual heating load [kWH]

new ES prog

ESP

BLAST

DOE2

SRES/SUN

SRES-BRE

S3PAS

TRYNSYS

TASE

Reasons for energy simulations

1) Building design improvement

2) System development

3) Economic benefits (pay back period)

4) Budget planning (fuel consumption)

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

• Engineering economics

Energy benefits

Parameters in life cycle cost analysis

Beside energy benefits expressed in $,you should consider:

• First cost• Maintenance• Operation life• Change of the energy cost • Interest (inflation)• Taxes, Discounts, Rebates, other Government

measures

Example

• Using eQUEST analyze the benefits (energy saving and pay back period)

of installing

- low-e double glazed window

- economizer

in the school building in NYC

Reasons for energy simulations

• System development

• Building design improvement

• Economic benefits (pay back period)

4) Budget planning (fuel consumption)Least accurate

Source of inaccuracywhen considering final results

• Assumptions related to the model

• Lack of precise input data

• Modeling software (tool) limitations

• Limitation related to available computational resources

• Result interpretations

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