1. Aristotelis Botzios-Valaskakis MSc Mechanical Engineer Division of Development Programmes Building Energy Performance Reliable Predictions ESCO’s point of view

2. Directive 32/2006 – On energy end-use efficiency and energy services (i) ‘Energy Service Company’ (ESCO): a natural or legal person that delivers energy services and/or other energy efficiency improvement measures in a user's facility or premises, and accepts some degree of financial risk in so doing. The payment for the services delivered is based (either wholly or in part) on the achievement of energy efficiency improvements and on the meeting of the other agreed performance criteria; (j) ‘Energy Performance Contracting (EPC)’: a contractual arrangement between the beneficiary and the provider (normally an ESCO) of an energy efficiency improvement measure, where investments in that measure are paid for in relation to a contractually agreed level of energy efficiency improvement;

3. ESCOs – Areas of Interest PRIMARY IMPORTANCE Existing large, public buildings Existing large buildings of the tertiary sector Existing industries with industrial processes SECONDARY IMPORTANCE Existing small-to-medium sized public buildings Existing small-to-medium sized buildings of the tertiary sector TERTIARY IMPORTANCE Residential buildings A CLASS OF ITS OWN New buildings

4. Guarantee of Performance (buildings) - 1 PHASE 1  Collection and analysis of all available information (i.e. technical Studies, maps, design drawings, weather data, boiler efficiency measurements etc.)  Collection and analysis of the energy bills of the building for the last three years (i.e. electricity, conventional fuels)  Visit to the building (i.e. verification and assessment of collected information)  Questionnaires and interviews regarding the use of the building and its equipment (i.e. occupancy, set temperatures, on/off of installations etc.)  Elaboration of plan of action for necessary measurements (i.e. electricity metering, conventional fuel consumption, indoor temperatures)  Implementation of measurements

5. PHASE 2 Simulation of energy performance of building PHASE 3 Calibration of simulation results (i.e. mainly via weather data and/or building use) Analysis of results and allocation of energy uses (i.e. lighting, hot water, heating, cooling etc.) PHASE 4 Proposal of energy efficiency measures Estimation of reduction in energy consumption via the calibrated simulation model Guarantee of Performance (buildings) - 2

6. CASE STUDY – OFFICE BUILDING IN CENTRAL ATHENS

7. Total building area = 42.617m 2 (7.128 m 2 for electromechanical equipment, 35.489 m 2 for offices, call centres and data centres) CASE STUDY – GENERAL INFORMATION

8. Month Temperature o C (Ambelokipi station) National Observatory Temperature o C (Elliniko station) HNMS Temperature o C (N. Philadelphia station) HNMS January10,610,38,7 February12,710,69,3 March13,812,311,2 April17,716,015,4 May22,220,7 June25,725,425,7 July28,728,1 August30,428,027,5 September24,524,323,4 October18,619,618,2 November18,115,413,8 December13,412,010,3 CASE STUDY – METEOROLOGICAL DATA

9. CASE STUDY – MEASUREMENTS Monitoring of electricity consumption of electrical substations in order to ascertain the weekly consumption profile. Instantaneous measurements of substation power factors and harmonic distortion Thermal imaging of external walls, interior of building, boiler-burner equipment, cooling equipment Illuminance levels (Lux) in selected representative rooms of the building Internal temperature and humidity in representative rooms of the building Temperature of cooling water going to and leaving the Fan Coil Units (FCU) Temperature of air leaving the FCUs

10. CASE STUDY – BUILDING SIMULATION TRNSYS 17 – A dynamic, hourly simulation model written in Fortran. EPA-NR a quasi-dynamic monthly simulation model. ΤΕΕ-ΚΕΝΑΚ the quasi-dynamic national monthly energy certification model.

11. CASE STUDY – BUILDING SIMULATION TRNSYS 17 – EPA-NR: + 15% divergence TRNSYS 17 – TOTEE-KENAK: + 40% divergence TRNSYS 17 – Measurements: -10 % divergence (open windows whilst smoking, lighting and FCU on during non-office hours, different occupancy scheduling, etc.)

12. Thank you for your attention! 19 o km. Marathonos Avenue, 19009 Athens, Greece Τel: 2106603300, Fax: 2106603301-2 www.cres.gr, cres@cres.gr