Lecture Objectives: -Discuss the final project presentations -Energy simulation result evaluation -Review the course topics

Oral presentation On Thursday class will start at 8:30 am –We will have some guests UTs PowerPoint (6-7 minutes presentation) –Upload the file before the class Approximately 6-7 slides (a minute per slide) –Problem introduction –Model development - specific problem –Results –Discussion –Conclusions

Today Lab Demo Class 5:30 PM in ECJ Beopt Software –Energy Plus GUI Presenter: Joshua Rhodes

How to evaluate the 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 COMPARE THE RESULTS

Example of best test comparison

BESTEST

Advance Energy Modeling with coupled energy and airflow Example: Night Cooling/Hybrid Ventilation The IONICA Office Building, Cambridge, UK

Night Cooling/Hybrid Ventilation: The IONICA Office Building, Cambridge, UK

Night Cooling/Hybrid Ventilation: Requires combined Energy and airflow modeling

Night Cooling/Hybrid Ventilation: The IONICA Office Building, Cambridge, UK

Feasibility of natural ventilation oCoC

Example of non-uniform temperature distribution with DV

Energy and Airflow simulation domain Coupling surfaces

Coupling Energy Simulation Program Air Flow Program IAQ Data: geometry weather materials T wall, CFM, T supply T near surface, h surface V,T,… Energy cons.

Coupling

COUPLED PROGRAM Components and Data flow

Energy Energy & Buildings 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

Accuracy of Your Energy Simulation Depends primarily on your input data! Geometry Boundary condition Selected models Set points Control Internal loads and schedule

Building Modeling Software Very powerful tool Use it wisely! Simulation Software Garbage INGarbage OUT but

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