2014 RAL CRC MADRID
CRC TP Topic 8- Good Practices & Challenges Towards Nearly Zero Energy Buildings Costas Balaras, PhD FASHRAE
[email protected] E. Dascalaki, PhD
P. Droutsa, MSc
Group Energy Conservation www.energycon.org
S. Kontoyiannidis, MSc www.facebook.com/GRoupEnergyConservation
Institute for Environmental Research & Sustainable Development www.meteo.noa.gr
National Observatory of Athens www.noa.gr
19th September 15:00
Learning Objectives • EU policies & regulations supporting energy efficiency in the building sector • Design priorities & available technologies for high performance buildings (HPB) • Challenges & Opportunities towards nearly zero energy buildings (NZEBs) • Predicted vs Actual Performance
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Outline • • • • • •
Buildings – Energy – IEQ Legislation High Performance Buildings Basics & More Moving towards NZEBs Predicted vs Actual performance; the real effectiveness of energy conservation measures
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NZEBs - UTOPIA or REALITY
INDOOR ENVIRONMENTAL QUALITY
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BUILDINGS ∼270 mil. mil. buildings
∼25 109 m 2
Final Energy Consumption: Consumption: 1103 1103..3 Mtoe Buildings:: 413.2 Mtoe (37.5% Buildings 37.5%)) Residential: 272.7 Mtoe (24.7%) Non--Residential: 140. Non 140.5 Mtoe (12. 12.7%) 7%)
Final Energy Consumption: Consumption: 86.5 Mtoe Buildings:: 25.7 Mtoe (29.7% Buildings 29.7%)) Residential : 16.2 Mtoe (18.7 (18.7% %) Non--Residential: Non Residential: 9.5 Mtoe (11.0 (11.0% %)
Source: Eurostat pocketbooks, 2013
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EU GOALS Initiatives on Climate Change (Kyoto commitments) & Security of Supply
Protocol
EU 20-20-20 targets by 2020 20% reduction in EU GHG emissions below 1990 levels total CO2 emissions in EU-27 reached about 4200 million tonnes CO2
20% RES contribution to EU’s gross final energy consumption from about 8% in 2007
20% reduction in primary energy use by improving energy efficiency gross inland consumption in EU-27 in 2007 reached about 1800 Mtoe
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EUROPEAN LEGISLATIVE EFFORTS EPBD (Directive 2002/91/EC on the energy performance of buildings) Energy end-use efficiency and energy services (Directive 2006/32/EC) Achieve by 2016 an overall national indicative energy savings target of 9% compared with average final energy consumption over 2001-2005, by energy services and other cost-effective, practicable and reasonable ECMs in the building sector (especially the public sector), promotion of energy service companies – ESCOs & third party financing - TPF arrangements, and EPBD implementation
Promotion of RES (Directive 2009/28/EC) Reach 20% from RES in gross final energy consumption by 2020
Solar hot water systems are now mandatory in new buildings according to EU solar ordinances (e.g. Spain, Portugal, Italy, Greece)
EPBD Recast (Directive 2010/31/EC) All new buildings must be NZEB after 1/2021, while new public buildings after 1/2019 All existing refurbished buildings (25% of building surface or value) should meet minimum energy performance standards, while national policies and specific measures should stimulate the transformation of refurbished buildings into NZEB Common calculation methodology for integrated energy performance of buildings using common benchmarks for calculating cost-optimal levels, minimising the building’s lifecycle cost Introduce minimum energy use requirements for all HVAC systems 7
Energy Performance of Buildings INDOOR
EPBD (91/20 2002 02)
ENVIRONMENTAL QUALITY
20 2006 06 Introduced energy efficiency of buildings onto political agendas, building codes & to public awareness
20 2009 09
EPBD recast (31/2010 2010)
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ΝΖΕΒ by the end of decade 2021
HIGH PERFORMING / GREEN / SUSTAINABLE BUILDINGS Different terms (17) used for low energy buildings Low energy house, high-performance house, passive house (passivhaus), zero carbon house, zero energy house, energy savings house, energy positive house, 3-litre house, etc Accounting for more than energy demand: eco-building, green building
Zero Energy / Zero Carbon Buildings Low energy needs; Remaining energy needs covered with RES
Nearly Zero Energy Buildings (NZEB) Very high energy performance, while the nearly zero or very low amount of energy required should be covered to a very significant extent by RES (on-site or nearby)
Net Zero Energy Buildings Can be autonomous from conventional power supply on an annual basis (may use some power from the grid but then feed it back to the grid in other periods)
Energy Positive Buildings On an annual basis, produce more energy from RES than it imports from external sources
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HIGH PERFORMING / GREEN / SUSTAINABLE BUILDINGS
High thermal envelope protection High passive solar gains Minimize infiltration No thermal bridges Proper solar protection Energy efficient HVAC (ventilation loads, equipment & system efficiencies, Service hot water) Minimize internal loads (energy efficient lighting, equipment-appliances – minimize plug loads) Controls Energy consumption for space heating & DHW: 30 kWh/m2 Swiss Std 2002, +26,000 buildings 15 kWh/m2 German Passivehouse Standard 0 kWh/m2 Swiss Std 2011, +200 buildings 10
BASICS •
Holistic climate responsive building design
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Optimize total lifecycle cost (LCC)
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Simulations
Minimize heating & cooling loads •
Use energy efficient equipment, systems
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Exploit RES (using cost effective solutions)
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Use proper controls
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Whole building Commissioning
… Maintenance 11
BASICS … EPBD PAVING THE WAY 1. BUILDING DESIGN Introduce an integrated design approach among the key-players (e.g. architects & engineers)
taking into account proper building space layout and orientation (exploiting of local climatic conditions) configuring the surrounding space (improving microclimate) openings for different orientations depending on direct solar gains, daylight and ventilation requirements arranging interior spaces depending on use and comfort requirements integrating passive solar system (direct solar gains, thermal mass walls, Trombe walls, attached greenhouse, etc) providing proper solar protection; integrating natural ventilation; exploiting daylight for visual comfort
2. THERMAL ENVELOPE - Minimize Loads New & refurbished building’s thermal envelope complies with lower U-values
3. E/M INSTALLATIONS – Efficient equipment & RES Introduce minimum specifications
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heat recovery proper thermal insulation of all heat and cold distribution pipes or ducts use of outdoor temperature compensation DHW recirculation with variable speed pumps coverage of the DHW load from RES energy efficient lighting with proper central control (e.g. non-residential buildings) thermostatic control in different thermal zones independent heating/cooling with heat meters power factor correction in non-residential buildings, etc.
BASICS … The Envelope Averaged U-values for floors, roofs & walls (W/m2K)
Facades TBC CTE 2007 NBE CT 79
Walls KENAK 2010
Walls TIR 1980
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Source: www.zerocarbonhub.org
BASICS … E/M Installations ECODESIGN (Directive 2005/32/EC) & Recast (2009/125/EC) Improving the environmental performance of energy-using products (EuP); recast extending to other energy related products (ErP) Initially included 14 product groups (“Lots”); now expanded to over 30 groups
http://ec.europa.eu/enterprise/policies/sustainable-business/ecodesign/index_en.htm http://ec.europa.eu/enterprise/policies/sustainable-business/documents/eco-design/legislation/framework-directive/
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BASICS • Domestic Hot Water (DHW)
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Source: Solar Heat Worldwide, 2012
BASICS & MORE • Domestic Hot Water (DHW) • Space Heating
Solar COMBI Systems
Middle-East North Africa
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Source: Solar Heat Worldwide, 2012
BASICS & MORE • Domestic Hot Water (DHW) • Space Heating
Solar COMBI Systems
EU market share: 5% of total solar thermal market Austria (40%), Switzerland (35%), Netherlands (20%), Denmark (15%), France (5%)
National regulations in several EU countries mandate the installation of solar collectors to cover part of the SHW and space heating load from solar thermal Greece: 60% of DHW demand in new buildings Ireland: 10 kWh/m2 floor space covered by RES in new buildings Portugal: 1 m2 collectors / occupant for DHW demand in new buildings Spain: 30-70% of DHW demand in new buildings Switzerland: 20% of heating demand covered by RES in new buildings
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BASICS & MORE • Domestic Hot Water (DHW) • Space Heating • • • • •
Solar COMBI Systems
Solar Collectors Heat Storage Heat Distribution Heat Dissipation Auxiliary (backup)
Design considerations
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Minimize heating loads Minimize heat distribution losses Good operation controls (higher complexity than solar SHW systems) Preheating with conventional hydronic systems (radiators) or coupled with subfloor heating systems (lower operating temperature)
BASICS & MUCH MORE • DHW Solar COMBI Systems • Space Heating + • Solar Cooling
COMBI-PLUS
Exploit solar & use installation throughout the year Peak cooling demand in summer is associated with high solar radiation availability => excellent opportunity to exploit solar energy with heat-driven cooling machines Improve performance of solar-combi systems Avoid collector stagnation Obstacles: High first cost, limited practical experience with design, control, operation, installation, maintenance Limited commercially available low power cooling systems, till recently 19
BASICS & MUCH MORE • DHW Solar COMBI Systems • Space Heating + • Solar Cooling • Solar Collectors
COMBI-PLUS
• Heat Storage • Heat Distribution • Heat-driven Cooling Unit • Cold Storage (optional) • Air Conditioning System • Cold Distribution • Auxiliary (backup) integrated at different places in the overall system: as an auxiliary heater parallel to the collector or the collector/storage or as an auxiliary cooling device or both 20
COMBI-PLUS
BASICS & MUCH MORE Thermal COP
ratio of cooling capacity to the heating power delivered to the system by solar, directly or indirectly through storage
Single-effect Absorption: 0.50 - 0.73 LiBr/H2O average 0.66 H2O/NH3 average 0.60
Adsorption: 0.59 Operate at a lower temperature Larger & heavier
Driving 52-82oC Temp.
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60-110oC
BASICS & MUCH MORE
66 120oC
COMBI-PLUS
Solar Collectors Flat plate (63%) 60-90°C Evacuated tube (21%) 80-120°C
COP increases with the driving temperature
Parabolic (16%) 97-165°C Adsorption & Absorption: 2 - 5 m²/kW
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Avg specific solar collector area: 3.6 m2/kW
COMBI-PLUS
BASICS & MUCH MORE 6474
Initial Cost
4444
Depends on: - Cooling capacity - Solar collector type - Stage of development - Working principle
3102
3521
Avg initial cost 4000 Euro/kW Dropping prices … 2000 Euro/kW
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BASICS & MUCH MORE
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Source: IEA SHC Task 48
COMBI-PLUS
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COMBI-PLUS
BASICS & MUCH MORE Hotel 35 rooms (2400 m2) Flat plate solar collectors (450 m2) Absorption chillers (105 kW)
Cosmetics factory (22000 m2) cover 40% of cooling load Flat plate solar collectors (2700 m2) Adsorption chillers (2 x 350 kW)
www.energycon.org/sace/sace.htm
Hotel 60 rooms (3000 m2) Flat plate solar collectors (500 m2) Absorption chillers (105 kW)
www.highcombi.eu
www.iea-shc-task25.org www.iea-shc.org/task38 25
HPB & Moving Towards NZEB The Solar estate `Solarsiedlung Freiburg am Schlierberg Freiberg, Germany. IEA SHC, Task 40, Annex 52
www.hpbmagazine.org
High Performance Buildings DATABASE http://buildingdata.energy.gov/ The EcoTerra™ house by Les Maisons Alouette, Eastman, Quebec, Canada. IEA SHC, Task 40, Annex 52
IEA SHC, Task 40, Annex 52 Towards Net Zero Energy Solar Buildings http://www.iea-shc.org/task40/ 26
HPB & Moving Towards NZEB Architectural integration of solar thermal energy systems www.iea-shc.org/task39/projects/projects.aspx
Ennstal - Neue Heimat – Wohnbauhilfe (ENW) Graz /Austria
Beddington Zero Energy Development (BedZED) London, UK
Hamburg Bramfeld, Germany
Penthouse Wien, Vienna, Austria
EXISTING BUILDING STOCK Need to achieve tangible results; Look for cost effective solutions; Target large scale applications Studies, Guidelines, Solutions, Existing know-how, Case Studies/demonstrations
Envelope – Active & Passive Solar
Solar Protection – Passive/Hybrid Cooling – Lighting – Efficient Systems Controls
Solar Heating & Cooling, PVs
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EXISTING BUILDING STOCK European Directives 31/2010 & 27/2012 Towards NZEB ... 2020 TOOLS & Theoretical Models for handling the building stock
ACTUAL energy consumption
Are they reliable ? ACTUAL operating conditions ACTUAL performance of national plans & strategies for energy conservation in buildings
TYPE OF SYSTEMS & PERFORMANCE of installations BREAKDOWN OF REFURBISHED BUILDINGS (Size - Age)
Do we monitor ?
ACTUAL PERFORMANCE of ECMs 29
PREDICTED-ACTUAL PERFORMANCE (Corrective Indicators for actual energy consumption)
EPCs (∼ ∼6,500 ) Primary Energy Consumption (Space Heating & DHW)
Actual energy consumption (kWh/m2)
SINGLE FAMILY HOUSING (1335 dwellings)
Primary Energy Consumption (Space Heating & DHW) MULTI FAMILY HOUSING (5139 dwellings)
Calculated energy consumption (kWh/m2)
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Calculated energy consumption (kWh/m2)
ENERGY CONSERVATION MEASURES (BEFORE & AFTER) HEATING SYSTEMS Oil to NG
BEFORE (kWh/m2)
HDDp
Heat Pumps Controls
AFTER (kWh/m2)(HDDR/HDDP)
AFTER (kWh/m2)
Energy Consumption (kWh/m2)
First findings
BEFORE (kWh/m2) (HDDR/HDDP) ΒΗΘΑ: τιµές αναφοράς για την περιοχή ΒHΘΠ: τιµές περιόδου
Weather Conditions Normalize with HDD 31
User interaction, assumptions, energy prices etc Number of buildings (data population)
ENERGY CONSERVATION MEASURES (BEFORE & AFTER)
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ENERGY CONSERVATION MEASURES (BEFORE & AFTER) BUILDING ENVELOPE Double Glazing
HEATING SYSTEMS Oil to NG
Thermal insulation
Heat Pumps Controls
First findings
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HDDR: reference values HDDA: actual for the period of consumption
Energy Performance Indicator Tracking Schemes for the Continuous Optimisation of Refurbishment Processes in European Housing Stocks
www.episcope.eu Closing the gap between DESIGN - BUILT - REFURBISH - OPERATE building performance
National Pilot Actions
Indicators for the effectiveness of Indicators for ECMs rates of refurbishment National building typologies
Realistic models for assessing ECMs
Tool Methodology for continuous monitoring of energy performance
Realistic assessment of potential energy savings
www.building-typology.eu 34
