Lecture Objectives:

• Discuss exam questions

• Define final project assignments

• Discuss major ES software

Requirement for the project

Email me (before Friday morning):• Final project group members • Project title• One paragraph (200-300 words) including

- Project objective - Methodology- Expected results

Any schematic drawing is welcome

Wednesday after 2 pm and Thursday after 11 am long office hours to discuss your project

Commercial BuildingsBuilding

1) Optimization of building envelops

glass area ,shading,….

2) Effect of internal loads on energy consumption

..................

Systems

1) Impact of HVAC systems

2) Design of solar system (PV or hot water)

……………..

Life cycle cost analysis in each project

Example of HVAC: water cooled chiller

Outside air 95°F

Inside 75°FWater 42°F

BuildingWater 52°FWater 120°F

Water 100°F

Cooling tower

Chiller

Task: analyze COP for the whole yearand different locations

Example of HVACthermal storage systems

(in combination with a cooling machine / heat pump)

Summer Winter

In the summer, the earth acts as a cooling tower. The Cooling Machine loads the loop with heat, sending warmed water to be cooled by the earth

In the winter, the earth acts as the boiler. The Heat Pump extracts heat from the loop, sending cooled water to be warmed by the earth.

Residential buildings

• It is very expensive to optimize each residential building• We optimize example buildings to develop local codes

UT Solar Decathlon 2007 Home Research Lab Test house (PRC)

Modeling for optimization of Home Research Lab (PSP)

Energy consumption in Austin’s residential house

2000 (15,600 kWh)Including gas

CoolingMiscellaneous

Range

Dryer

Heating

Lighting

Hot water

Refrigerator

Washer

Analyze impact of:• envelope• Internal loads • HVAC systemsConduct life cycle const analysis

See handout section

More final project topics:Software (eQUEST) based

• Energy analysis of building form Integrated design course, • Any other building or building system

Detail Modeling (your model)

• Heat recovery systems, • Attic problem,• Mass transfer (moisture,…) • Vented cavity walls - exam problem• Green house model

Your ideas…

Project Grading

• GRADING CRITERIA (30% of your final grade):• 1) Analysis approach: 60%• - Modeling quality 20%• - Result accuracy 20%• - Result analysis 20%• 2) Deliverables: 40%• - Quality of the final report 25%• - Quality of oral presentations 15%

• Undergraduate students – Engineering report

• Graduate students– Research report

Project Timeline

• 11/11/11 – project defined and approved

• 11/22/11- generated preliminary results

• 12/01/11 - oral presentation

• 12/05/11 - project paper submission

Structure of ES programs

SolverInterface for input data

Graphical User Interface (GUI)

Interface for result presentation

Preprocessor Engine

Preprocessor

ASCIfile

ASCIfile

Modeling steps

• Define the domain

• Analyze the most important phenomena and define the most important elements

• Discretize the elements and define the connection

• Write energy and mass balance equations

• Solve the equations

• Present the result

ES program

Preprocessor

Solver

Postprocessor

Characteristic parameters

• Conduction (and accumulation) solution method – finite dif (explicit, implicit), response functions

• Time steps • Meteorological data• Radiation and convection models (extern. &

intern.) • Windows and shading• Infiltration models• Conduction to the ground• HVAC and control models

ES programs

• Large variety • http://www.eere.energy.gov/buildings/tools_directory

• DOE2• eQUEST (DOE2)• BLAST • ESPr• TRNSYS• EnergyPlus (DOE2 & BLAST)

eQUEST (DOE2)US Department of Energy & California utility customers

• eQUEST - interface for the DOE-2 solver• DOE-2 - one of the most widely used ES program - recognized as the industry standard • eQUEST very user friendly interface • Good for life-cycle cost and parametric analyses

• Not very large capabilities for modeling of different HVAC systems

• Many simplified models • Certain limitations related to research application - no capabilities for detailed modeling

ESPrUniversity of Strathclyde - Glasgow, Scotland, UK

• Detailed models – Research program • Use finite difference method for conduction• Simulate actual physical systems • Enable integrated performance assessments

Includes daylight utilization, natural ventilation, airflow modeling CFD, various HVAC and control models

• Detail model – require highly educated users• Primarily for use with UNIX operating systems

TRNSYSSolar Energy Lab - University of Wisconsin

• Modular system approach • One of the most flexible tools available • A library of components • Various building models including HVAC • Specialized for renewable energy and emerging

technologies

• User must provide detailed information about the building and systems

• Not free

EnergyPlusU S Department of Energy

• Newest generation building energy simulation program ( BLAST + DOE-2)

• Accurate and detailed• Complex modeling capabilities• Large variety of HVAC models• Some integration wit the airflow programs Zonal models and CFD

• Detail model – require highly educated users • Very modest interface• Third party interface – very costly