Buildings & Energy Paradoxes & Paradigms

Transkript

1 Buildings & Energy Paradoxes & Paradigms Rob Marsh Senior Researcher Architect MAA PhD SBi Energy & Environment Danish Building Research Institute University of Aalborg

2 Past Present Future

3 Giv indeklimaet og økonomien et friskt pust Panasonic varmepumpe Luk op for varmen med en Panasonic varmepumpe, og nyd de fordele, det giver for hele familien. I får et sundt indeklima, varmebesparelser på op til 66% samt et miljøvenligt varmeanlæg, der er let at betjene. Varmepumpen kan også køle jeres bolig ned på varme sommerdage.

4 Past

5 Past: Existing building stock Total housing stock : Low population growth: + 7% Growing floor area: + 50% Falling heat consumption: - 20% Growing electricity use: + 70% Relativ ændring (1975 = 100 %) 250% 200% 150% 100% 50% 0% Figur 1. Relativ ændring Samlet i befolkningstal befolkning, etageareal Samlet etageareal Samlet varmeforbrug Samlet elforbrug (Energistyrelsen, 2007).

6 Past: Existing building stock 250% Total office stock : Relativ ændring (1975 = 100 %) 200% Growing floor area: + 55% 150% Falling heat consumption: + 10% 100% Growing electricity use: + 160% 50% 0% Figur 1. Relativ ændring Samlet i befolkningstal befolkning, etageareal Samlet etageareal Samlet varmeforbrug Samlet elforbrug (Energistyrelsen, 2007). Relativ ændring (1975 = 100 %) 250% 200% 150% 100% 50% 0% Figur 3. Relativ Samlet ændring etageareal i etageareal og energiforbrug Samlet varmeforbrug Samlet elforbrug (Dansk Ejendomsmæglerforening, 2007; Sadolin &

7 Past: Existing building stock Relativ ændring (1975 = 100 %) 250% Total office stock : 200% Growing floor area: + 55% 150% Falling heat consumption: + 10% 100% Growing electricity use: + 160% 50% Relativ ændring (1975 = 100 %) 250% 200% 150% 100% 50% 0% Figur 1. Relativ ændring Samlet i befolkningstal befolkning, etageareal Samlet etageareal Samlet varmeforbrug Samlet elforbrug (Energistyrelsen, 2007). 0% Figur 3. Relativ Samlet ændring etageareal i etageareal og energiforbrug Samlet varmeforbrug Samlet elforbrug (Dansk Ejendomsmæglerforening, 2007; Sadolin &

8 Past: Existing building stock Falling/stable heat consumption: - Insulation of existing building fabric; window refurbishment - New heating system; change in heat supply - Improved energy regulations in Building Regulations

9 Past: Existing building stock Extreme growth in electricity consumption: - Growing ownership rates for electrical appliances - Growth in Knowledge Society, IT/multimedia og service sector - New buildings with high electricity usage to lighting, ventilation, cooling

10 Past: Typical new buildings through time New build housing : Falling heat consumption: - 60% Growing electricity use: + 10% Primærenergiforbrug kwh/m Figur 2. Primærenergiforbrug Varmeforbrug nybyggede boliger Elforbrug

11 Past: Typical new buildings through time Primærenergiforbrug kwh/m New build offices : 150 Falling heat consumption: - 60% Growing 100 electricity use: + 55% Figur 2. Primærenergiforbrug Varmeforbrug nybyggede boliger Elforbrug Primærenergiforbrug kwh/m Figur 4. Primærenergiforbrug Varmeforbrug for nybyggede kontorer Elforbrug

12 Past: Typical new buildings through time Primærenergiforbrug kwh/m Primærenergiforbrug kwh/m Figur 2. Primærenergiforbrug Varmeforbrug nybyggede boliger Elforbrug Figur 4. Primærenergiforbrug Varmeforbrug for nybyggede kontorer Elforbrug Major transformation since 1970's oil crisis: - Improvements in energy regulations giving large heat savings - Growing electricity consumption has not been regulated

13 Paradox 1 Primary energy Primærenergiforbrug consumption Rising Stigende electricity elforbrug consumption Focus on space heating savings corresponds with Past Fortid Falling Faldende heat consumption varmeforbrug Present Nutid Rising electricity consumption

14 Paradox 1 Primary energy Primærenergiforbrug consumption Rising Stigende electricity elforbrug consumption Focus on space heating savings contributes to Past Fortid Falling Faldende heat consumption varmeforbrug Present Nutid Rising electricity consumption

15 Paradigm 1 Historical narrow focus on space heating from 1977 to 2006 Say: Energy savings Mean: Heat savings Primærenergiforbrug kwh/m Everything else 's house Space heating

16 Paradigm 1 Focus on reducing space heating has created negative energy and indoor climatic consequences Primærenergiforbrug kwh/m Everything else 's house Space heating

17 Low energy paradigm: Passive solar Concept developed i 's: - Mountainous zones with considerable sunshine in the winter - Large south-facing glazed areas to minimise heating Used in Denmark from 1970's despite different climate: - Cloudy or overcast sky for 80 % of daylight hours in the winter - Well known projects with documented summer overheating problems

18 Low energy paradigm: Passive solar - Narrow low energy paradigm with focus on space heating - Passive solar energy reduces space heating demand Opvarmningsbehov kwh/m Syd: 10 % 40 % 70 % Nord: 70 % 40 % 10 % Facadens glasandel som procentdel af facadeareal Figur 5. Opvarmningsbehov og passiv solvarme for en typisk bolig beregnet i henhold til BR-S98.

19 Low energy paradigm: Passive solar - 60 Wider low energy paradigm with 40 focus on space heating Opvarmningsbehov kwh/m 2 and overheating/cooling 20 - No advantage from 0 Syd: passive 10 % solar 40 energy % 70 % Nord: 70 % 40 % 10 % Facadens glasandel som procentdel af facadeareal because of overheating Figur 5. Opvarmningsbehov og passiv solvarme Primærenergiforbrug kwh/m Syd: 10 % 40 % 70 % Nord: 70 % 40 % 10 % Facadens glasandel som procentdel af facadeareal Overtemperatur Opvarmning

20 Low energy paradigm: Passive solar Opvarmningsbehov kwh/m Syd: 10 % 40 % 70 % Nord: 70 % 40 % 10 % Facadens glasandel som procentdel af facadeareal Figur 5. Opvarmningsbehov og passiv solvarme for en typisk bolig beregnet i henhold til BR-S98. Primærenergiforbrug kwh/m Syd: 10 % 40 % 70 % Nord: 70 % 40 % 10 % Facadens glasandel som procentdel af facadeareal Overtemperatur Opvarmning Same building; different low energy paradigms: - Narrow low energy paradigm creates invisible problems - Heat consumption replaced by electricity consumption

21 Low energy paradigm: Mechanical heat recovery ventilation Heat recovery efficiency: 65 % - 90 % Systems have a relatively high electricity consumption: - Deep buildings with internal rooms must be ventilated mechanically all year round - Always advertised by high heat recovery efficiency - Data on electricity consumption hidden

22 Low energy paradigm: Mechanical heat recovery ventilation - Narrow low energy paradigm with focus on space heating - Mechanical heat recovery reduces space heating demand Opvarmningsbehov kwh/m Mekanisk Mekanisk Naturlig udsugning varme- ventilation genvinding Figur 7. Opvarmningsbehov og ventilationsløsning for en typisk bolig beregnet i henhold til BR-S98.

23 Low energy paradigm: Mechanical heat recovery ventilation - 60 Wider low energy paradigm Opvarmningsbehov kwh/m 2 with 40 focus on space heating and electricity to building services 20 - No difference between 0 natural ventilation and mechanical heat recovery Mekanisk Mekanisk Naturlig udsugning varme- ventilation genvinding Figur 7. Opvarmningsbehov og ventilationsløsning Primærenergiforbrug kwh/m Mekanisk Mekanisk Naturlig udsugning varme- ventilation genvinding Figur 8. Primærenergiforbrug og ventilationsløsning Teknik Opvarmning

24 Low energy paradigm: Mechanical heat recovery ventilation Opvarmningsbehov kwh/m Mekanisk Mekanisk Naturlig udsugning varme- ventilation genvinding Figur 7. Opvarmningsbehov og ventilationsløsning for en typisk bolig beregnet i henhold til BR-S98. Primærenergiforbrug kwh/m Mekanisk Mekanisk Naturlig udsugning varme- ventilation genvinding Figur 8. Primærenergiforbrug og ventilationsløsning Teknik Opvarmning Same building; different low energy paradigms: - Narrow low energy paradigm creates invisible problems - Heat consumption replaced by electricity consumption - No energy saving from mechanical heat recovery (until 2010)

25 Low energy paradigm Low energy housing until 2006: Low energy? - No! - Low space heating demand - High electricity consumption - Overheating & high cooling demand - Same primary energy consumption as ordinary housing without specific heat saving strategies

26 Present

27 Present: Energy regulations Danish regulations : - Space heating demand Danish regulations 2006-: - Heating - Hot water - Cooling/overheating - Building services - Renewable energy production from solar thermal & PV - Weighted in relation to primary energy consumption: District heat/oil/gas: 1.0 Electricity: 2.5

28 Present: Primary energy factors District heating: Fjernvarmeforbrug: 1,00 kwh Electricity: Elforbrug: 1,00 kwh Distributionstab: 0,25 kwh Eksport: 0,33 kwh Distributionstab: 0,05 kwh Spildvarme: 0,46 kwh Eget forbrug: 0,08 kwh Import: 0,26 kwh Produktionstab: 1,44 kwh Primærenergiforbrug: 0,79 kwh Primærenergiforbrug: 2,64 kwh Figur 10. Anvendt primærenergi forbundet med Energy regulations : 1,00 Primary energy: 1,00 CO2 emissions: 1,00 Energy regulations: 2,50 Primary energy: 3,30 CO2 emissions: 4,20

29 Primary energy factors: Existing housing stock Heat consumption Electricity consumption 19 % 38 % 62 % 51 % 49 % 81 % Measured energy Primary energy CO2-emissions

30 Paradigm 2 Primary energy Primærenergiforbrug consumption Electricity Elforbrug: 70% % Heat 30% Varmeforbrug: 30 % Apparater: 40 % Belysning: 10 % Teknik: 10 % Overtemperatur: 10 % Varmt brugsvand: 10 % Opvarmning: 20 % Ikke omfattet af energibestemmelser: 50 % Not covered by energy Regs. 50 % Covered by Omfattet af energy energi- Regs. bestemmelser: 50 % 50% New buildings Nye energy bygningers consumption energiforbrug Focus on primary energy/co2 radically changes energy balance of buildings Focus of Energy Regulations covers less than half total primary energy consumption

31 Paradox 2 Current focus on Energy Regulations and Low Energy Classes for Primærenergiforbrug kwh/m Everything else Building services Overheating/cooling Hot water 'ernes 2000's energ house Space heating

32 Paradox 2 Current focus on Energy Regulations and Low Energy Classes for 2010: 25 % reduction 2015: 50 % reduction 2020: 75 % reduction Primærenergiforbrug kwh/m 2 Everything else 2020'ernes 2020's lavene house Building services Overheating/cooling Hot water Space heating

33 Paradox 2 Current focus on Energy Regulations and Low Energy Classes for 2010: 25 % reduction 2015: 50 % reduction 2020: 75 % reduction Everything else expected to grow 25% because of increased electricity to IT/multimedia Actual saving in total primary energy = 30 % Primærenergiforbrug kwh/m 'ernes 2020's lavene house Everything else Building services Overheating/cooling Hot water Space heating

34 Future

35 Future: Low energy demonstration projects We have seen the future: - and it does not look good!

36 Future: Low energy demonstration projects Two projects aiming at LE2015 or Passive House standard: - Comfort House - Future Detatched House Afrapportering til Energiforskningsprogrammet 2007 Det Grønne Hus i samarbejde med SBi Erfaringsopfølgning på lavenergibyggeri klasse 1 og 2. - med "Fremtidens Parcelhuse" som eksempel Udarbejdet af: Lars Kristensen og Ole Michael Jensen (red.) Bidrag fra: Heidi Arvedsen (DGH), Niels Christian Bergsøe (SBi), Ole Michael Jensen (SBi), Henrik N. Knudsen (SBi), Jesper Kragh (SBi), Lars Kristensen (DGH), Tommy Olsen (DGH), Torben Valdbjørn Rasmussen (SBi) Vurdering af indeklimaet i hidtidigt lavenergibyggeri - med henblik på forbedringer i fremtidens lavenergibyggeri Tine Steen Larsen Udarbejdet for: Erhvervs- og byggestyrelsen DCE Contract Report No. 100 Institut for Byggeri og Anlæg

37 Future: Low energy demonstration projects Overall conclusions: - Too much overheating - Occupants use mini-coolers - Too much south-facing glass - No/fixed solar shading - Mechanical ventilation designed for winter, not summer - Not possible to use natural ventilation - Occupants cannot control indoor comfort - BMS cannot control building services Afrapportering til Energiforskningsprogrammet 2007 Det Grønne Hus i samarbejde med SBi Erfaringsopfølgning på lavenergibyggeri klasse 1 og 2. - med "Fremtidens Parcelhuse" som eksempel Udarbejdet af: Lars Kristensen og Ole Michael Jensen (red.) Bidrag fra: Heidi Arvedsen (DGH), Niels Christian Bergsøe (SBi), Ole Michael Jensen (SBi), Henrik N. Knudsen (SBi), Jesper Kragh (SBi), Lars Kristensen (DGH), Tommy Olsen (DGH), Torben Valdbjørn Rasmussen (SBi) Udarbejdet for: Erhvervs- og byggestyrelsen DCE Contract Report No. 100 Vurdering af indeklimaet i hidtidigt lavenergibyggeri - med henblik på forbedringer i fremtidens lavenergibyggeri Tine Steen Larsen Institut for Byggeri og Anlæg

38 Paradox 3 Primary energy Primærenergiforbrug consumption Rising Stigende cooling køling demand Falling Faldende space heating opvarmning demand Reduced space heating demand results in Rising cooling demand 6 Past Nutid Present Fremtid

39 Paradigm 3 Heat balance in new low energy buildings is radically different: - Heat savings - Growing electricity consumption - Larges glass facades - User demands - Climate change Summer conditions dominate; not winter

40 What is a low/zero-energy building? - Do we need wider demands to energy and indoor climate? How should passive and active solutions be balanced? - Regulative demand to building design and/or technologies? How can users and occupants control low/zero energy buildings? - Can we open the windows?