1. Lecture Objectives: Show example of life-cycle cost analysis
integrated in eQUEST
Discuss accuracy of energy modeling
Learn about moisture transport

2. Economic benefits Life Cycle Cost Analysis
Engineering economics
Energy benefits

3. 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

4. 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

6. Reasons for energy simulations
System development
Building design improvement
Economic benefits (pay back period)
Budget planning (fuel consumption)

7. System development Example: glass facade design tool
THERM: heat thermal bridge analysis

8. Therm

9. Detailed model Load System Plant Model Building Heating/Cooling System
QBuilding
QSystems
eQUEST
Integrated Model
Building
Heating/Cooling
System
Plant
QBuilding
QSystems
EnergyPlus
Feedback

11. Evaluate of the whole building simulation tools
Two options:
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

12. Source of inaccuracy when 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

13. How to evaluate the whole building simulation tools
Two options:
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

14. Comparison with measured data
Cranfield test rooms (from Lomas et al 1994a)

15. 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

16. Example of best test comparison

17. Moisture transport (WUFI)

18. Moisture transport - fundamentals
However, you should be very carful how you use vapor barrier !
Theory & application (on the whiteboard)