Daylight and thermal comfort in a residential passive house

Transkript

1 Daylight and thermal comfort in a residential passive house A simulations study based on environmental classification systems Magnus Heier Magnus Österbring Supervisors: Paula Wahlgren, Chalmers Tekniska Högskola Christian Johansson & Anders Ljungberg, NCC Teknik

2 Bakgrund Standarder och Syfte Kuben Simulationsmetodik Undersökta parametrar Resultat Dagsljus Solvärmelast Slutsatser Agenda

3 Bakgrund - Standarder

4 Background - BCS

5 Background - Aim Increase in demand for building classification systems Passivehouse technology in high demand Opposing demands Smaller buildings are more critical How does the choice of window and shading affect the heating demand in a passive house? How does the choice of window and shading affect the indoor climate? How can the glass to floor area ratio be optimized with regard to heating demand and indoor climate? How can the design process be optimized for early stages?

6 KUBEN

7 Simuleringsmetodik

8 Programvara - undersöka parametrar IDA Indoor Climate and Energy Energianvändning Effektbehov Termiskt klimat, vinter Termiskt klimat, sommar IDA ICE 4,2

9 Programvara - undersöka Parasol Solvärmelast parametrar Velux daylight visualizer Dagsljusfaktor

10 Results Parameter Bronze Silver Gold Passivehouse Achieved Level reached Energy demand [kwh/m²] 90 67,5 58, Gold Guld Power demand [W/m²] Gold Guld Solar heat load [W/m², floor area] Silver Thermal comfort winter [%] Gold Guld Thermal comfort summer [-] (SVF) <0,048 <0,036 <0,025 0, Gold Guld Daylight factor [%] 1,0 1,2 1,2-0.8 Insufficient Klassad

11 Dagsljus värsta rum N

12 Daylight - measures Measure Window properties Window size High reflective paint Window niche Combinations Will affect Solar heat load Daylight factor Energy/power demand

13 Window properties g-value (SHGC) LT-value U-value LT

14 Ändring: glasegenskaper 1,3 1,2 Daylight Factor [%] 1,1 1 0,9 0,8 0,7 Original 0.5/57/ /63/ /67/ /71/ /79/0.59 [U glass /LT/g ] 0, Annual energy demand [kwh/m²]

15 Ändring: storlek Orginal 10 % 20% 30% Uppvärmningsbehov [kwh] Värmeeffektbehov [W/m²] 15,7 15,9 16,1 16,4 Solvärmelast [W/m², golv area] 19,9 22,8 25,4 28,1 Dagsljus faktor [%] 0,8 1,0 1,1 1,2

16 Ändring: Fönstersmyg Fönstersmyg 0 (orginal) Uppvärmningsbehov[k Wh] Dagsljus faktor[%] 0,8 0,9 0,9 0,9

17 Possible solutions A Reflective paint, 30º inclined window nische, LT = 0,71 B 10% larger windows, LT = 0,71 C 30% larger windows, LT = 0,71 D 30% larger windows, LT = 0,57

18 Results for combinations Parameter Gold Passive house Standard Case A Case B Case C Case D Daylight factor[%] Energy demand [kwh/m²] Power demand [W/m²] Solar heat load [W/m², floor area] 1,2-0,8 1,2 1,2 1,5 1,2 0,8 1,2 1,2 1,5 1,2 58, ,9 49,5 49,4 50,1 51, ,7 16,2 16,3 16,8 16, ,9 26,8 30,1 38,2 27,6 Thermal comfort winter, [%] PPD 10-8,12 8,14 8,15 8,18 8,15

19 Solvärmelast värsta rum N

20 Simulation methodology

21 Solar heat load - suggestions Adding Venetian blinds Roller-blinds Awnings Increased soffit (roof overhang) Will affect SVL Energy usage Daylight factor g sys 0,2

22 Shading Blinds Roller Blinds Awnings Fixed shading 0,0 6,0 12,0 18,0 24,0 30,0 36,0 42,0 Solar Heat Load [W/m²] A; g=0.52 B; % C; g= % D; g= %

23 Working cases Awnings Blinds Roller-blinds Awnings A reflecting paint, 30º window niche inclination, LT = 0.71 B 10% area added, LT = 0.71 Awnings Fixed shading + blinds Fixed shading + roller blinds Awnings C 30% area added, LT = 0.71 D 30% area added, LT = 0.57

24 Design path

25 Slutsatser Ett högre U-värde kan vägas upp av ett högre g-värde Leder också till ökat ljusinsläpp Ökad fönsterarea kan leda till minskad energianvändning Viktigt att ta riktning i beaktning Rörlig solavskärmning är att föredra Måste styras på ett korrekt sätt Fast solavskärmning påverkar dagsljus negativt All solavskärmning leder till ökad energianvändning Fönster med lägre g-värde är svårare att skugga med intern solavskärmning Fönstersmyg och reflekterande färg har begränsad effekt Arbetsgång I tidiga skeden

26 Conclusions A higher ( worse ) U-value can be offset by an increased g-value Also increases daylight Larger windows may lead to lowered energy demand Important to consider orientation Movable shadings, and especially awnings, have superior flexibility, and does not affect daylight Highly dependant on control systems Fixed solutions do affect daylight All shading devices lead to an increased energy demand Windows with low g-values are more difficult to shade internally Inclining the window nisch & reflecting paint are more difficult to implement A design path was developed to decide window type and placement in early stages, focused around window properties.

27 Daylight and thermal comfort in a residential passive house A simulations study based on environmental classification systems THANK YOU

28 Daylight and thermal comfort in a residential passive house Is the passive house standard holistic enough? Does the methodology fit small housing? Does it fit all buildings?

29 Working solutions Parameter Daylight [%] Solar heat load [W/m², floor area] Energy [kwh/m² floor area] Installed power [W/m² floor area] Thermal climate winter, PPD [%] Thermal climate summer, SVF [W/m²] Guld 1, , <0,024 Passive house ,036 Original 0,8 19,9 49,8 15,7 8,12 0,025 A - blind 1,2 17,1 48,7 16,2 8,14 0,021 A - roller-blind 1,2 16,4 48,8 16,2 8,14 0,020 C roof extension & blind 1,4 17,9 49,4 16,8 8,18 0,022 C roof extension and 1,4 16,9 49,6 16,8 8,18 0,021 roller-blind A awning 1,2 3,6 51,0 16,2 8,14 0,0045 B awning 1,2 3,6 51,0 16,3 8,15 0,0045 C awning 1,5 5,4 51,7 16,8 8,18 0,0067 D - awning 1,2 2,9 51,8 16,4 8,15 0,0037

30 Shading #2 Blinds Roller Blinds Awnings Fixed shading 0,00 0,10 0,20 0,30 0,40 0,50 0,60 0,70 0,80 0,90 1,00 g-value for the shading system A; g=0.52 B; g= % C; g= % D; g= %

31 Required shading Solar heat load [W/m²] ,00 0,10 0,20 0,30 0,40 0,50 0,60 0,70 0,80 0,90 1,00 g-value for shading system A; g=0.52 B; g= % C; g= % D; g= % C; Combinations

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34 Orientation 51,5 51,0 Annual energy demand [kwh/m²] 50,5 50,0 49,5 49,0 48,5 48,0 47,5 47, Orientation

35 Daylight factors, original

36 Daylight and window size 6,0 5,0 Daylight factor {%] 4,0 3,0 2,0 1,0 0,0 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Room depth [%] Original 10% 20% 30%

37 Reflective paint Case Standard 90% reflectance 100% reflectance Daylight factor [%] 0,8 0,9 1,0

38 Moveable shading

39 Additional figures

40 Energy levels

41 Det går inte att visa den länkade bilden. Filen kan ha flyttats, fått ett nytt namn eller tagits bort. Kontrollera att länken pekar på rätt fil och plats. Conclusions PPD for thermal comfort summer Choice of window Choice of window size Windowsill inclination Reflecting paint Shading to use Calculation standards on safe-side Issues with software Miljöbyggnad

42 Orientation Daylight factor External shading Analysis