METHODS FOR BUILDING ENERGY ANALYSIS

1. METHODS FOR BUILDING ENERGY ANALYSIS -experience of the Technical University –Sofia and the BSREC Dr. N. Kaloyanov

2. INTRODUCTION The aim of this presentation is to share the experience of the Technical University of Sofia and the Black Sea Regional Energy Centre - Bulgaria in adaptation of a systematic approach for building energy analysis and practical implementation of energy management program based on that.

3. THE BUILDING IS AN INTEGRATED SYSTEM

4. STAGES AND CONTENT of the EA • Stage 1.Collection of primary data about the building (for a past period, usually 2-3 years) including: • basic parameters of the building; function, construction, geometry,…; • energy consumption and costs; • operating conditions; • local climate data . • Stage 2. Data analysis • - determining the share of the energy carriers used; • - correlating the energy consumption and the climate data, performing comparative analyses and determining the energy saving potential. Preliminary analysis

5. Stage 3. Collection of detailed data about the significant energy resources, processes and systems by inspecting the building and measurements. Stage 4. Detailed data analysis for determining the real energy saving potential - by statistical methods; - by modelling and simulation. Stage 5. Generation of ECM - generating of energy saving measures , the so called “long list”; - ranging the long list measures by the “Simple Payback period” criterion. Stage 6. Drawing up “a short list” of measures - selecting the substantial energy conservation measures from the long list; Detailed analysis

6. - collecting data from the equipment suppliers; - detailed technical, economic and risk analysis of the selected measures; - evaluation of packages of ECM. Stage 7. Selecting measures for implementation Stage 8. Developing a plan for implementing the measures Stage 9. Developing a plan for staff training and monitoring Stage 10. Preparing the final report on the results obtained.

7. THE PRELIMINARY ENERGY ANALYSIS APPROACH • ENGINEERING APPROACH. A detailed analysis of the system components is carried out and it serves as a basis for making the evaluation /bottom-up/. • SYSTEMATIC APPROACH. Evaluation of the energy consumption and energy management efficiency based on limited number of data. • Statistical methods - mostly regression and correlation analysis. • Methods for mathematical modelling and simulation of the energy transfer processes.

8. energy CUSUM time

9. Building zoning Zone function Operating regime Equipment Building envelope Heat and electricity consumption Test reference year (climate data) System model Model calibration Model “normalisation” 7 5 4 6 2 1 3 Determining the baseline Simulation of ECM Economic evaluation THE PROCEDURE

10. THE TOOLS FOR MODELLING … Simple for use from:“Manual methods and procedures“ based on correlations ( LT method, NORMA .....) trough:Specialised modules (as for daylighting calculations or CFD) to : Most advanced software for system analysis (TRNSYS..) and state-of-the-art simulation environment (ESP). Precision

11. Heat losses distribution Windows Infiltration 34% 38% Doors Walls Roof 0% 13% 15% 3

12. 4 5 NORMALISED BASELINE Baseline, corresponding to the comfort requirements

13. К5 К4 К3 К2 К1 С4 С3 Energy conservation measure С1 В6 В5 В4 В3 B2 B1 0.00 5.00 10.00 15.00 20.00 25.00 30.00 35.00 40.00 45.00 50.00 Energy savings, % К5 К4 К3 К2 К1 С4 С3 Energy conservation measure С1 В6 В5 В4 В3 B2 B1 0.00 5.00 10.00 15.00 20.00 25.00 30.00 Payback period, years LONG LIST ECM /SINGLE AMD MULTIPLE/

14. 7 ECONOMIC EVALUATION OF THE ECM • A. Long list ECM , ranged by SPB • Simple Payback Period • B. After the annual energy savings have been determined, an extensive economic assessment is performing based on information, collected from equipment suppliers. • The following economic criteria are convenient for this step: • Net Present Value (NPV) • Internal Rate of Return (IRR)

16. C. ASSESSMENT OF THE FINANCIAL RISK • Final step in the economic evaluation is the sensitivity analysis, done in order to analyse the influence of the main factors as: • Interest rate, • Inflation rate • Energy Savings • Initial costs • Energy price • on the economic criteria NPV and IRR.

17. Q SOME RESULTS 1. Updated and new equations for calculating air temperature in unheated “attic space” – buildings and industrial refrigerators 2. Evaluation of the influence of “disconnected radiators ” in multy-family buildings on the thermal comfort and energy use 3. Development of national rules for heat allocation 4. Energy analyses and management in residential, public and industrial buildings

18. 1. Updated and new … Q The existing formula

19. 1. Updated and new … Q Structure of the new formula

20. 1. Updated and new … Q An example….

21. 2. Influence of “disconnected…”

22. Influence of the apartment location on the energy use

23. 4. Energy analyses of buildings

24. The Hospital of Gabrovo ....Russe

25. ….the TU of Sofia

26. ...historical greenhouse CEC - Sofia

27. …the National Theatre, the National Opera, the National Library in Sofia…

29. May 2002 ...

30. October 2002...

31. Internet based system for monitoring

34. Method for building energy scanning • reference (key) numbers • reference climate • …..