Architectural integration of solar thermal collectors into the building envelope

Transcription

1 Architectural integration of solar thermal collectors into the building envelope Charlotta Isaksson, Thomas Müller, Irene Bergmann AEE - Institute for Sustainable Technologies (AEE INTEC) A-8200 Gleisdorf, Feldgasse 19 AUSTRIA Architectural integration Façade integration Particularities Examples Test system temperature and humidity Colored absorber architectural acceptance Examples

2 Facade integrated collectors Energy converter Improving the insulation (decreasing U-value) Weather resistant Design element of the façade, part of architecture, visible collector presenting company philosophy New market: alternative to collector placement on the roof Application in new buildings and retrofit objects Consequences of the architectural integration Standardized collector sizes only rarely possible Architect decides modular grid of the facade Modular grid of the building does not coincide with absorber size Early cooperation with architects and planers is necessary Why facade integration?

3 Collector as part of the building envelope Photo: TiSun, Arch. Mathoy Photo: AKS Doma Photo: AKS Doma Irradiation in the facade [kwh/m²,mon] kwh/m²mon, 45 kwh/m²mon, 90 [kwh/m²a] Jan Feb Mrz Apr Mai Jun Jul Aug Sep Okt Nov Dez Monat 0 Süd Meteonorm Data, Graz

4 Dimensioning 70 Deckungsgrade bei verschiedenen Kollektorflächen bei Dachintegration und Fassadenintegration (EFH, selektiver Kollektor, 2000l Energiespeicher +300l Warmwasserspeicher, 160 l/d Warmwasserbedarf) 60 Solarer Deckungsgrad [%] Kollektorneigung Collector angle 90 Kollektorneigung Collector angle Collector Kollektorfläche area [m²] Façade integration: larger collector area than collectors with < 90 necessary Reflection from the ground: snow scenario [kwh/m²] Strahlung Increase November of irradiation bis Februar November to February +5% +20% , Schnee snow 90 90, Schnee snow

5 Shading: projecting roof Test system: light wall construction 3 collector fields at 18.3 m² Each with 10 mounting points

6 Test system: light wall construction Inside Innen 50 mm 160 mm 40 mm Outside Außen Vapour barrier (Sd = 0.8 m), air dense Temperature and humidity sensors in every layer Test system: light wall construction 55 m², 3,600 litres stratified storage tank, 500 litres domestic hot water tank

7 Test system: light wall construction: humidity relative Relative Feuchte humidity [%], mean Monatsmittelwert month values rh zwischen Between absorber Absorber and und glass Glas [% rh] [% rh] rh Kollektordämmung Collector insulation [% [% rh] rh] rh vor Outside Gebäudedämmung building insulation [% rh] rh nach Inside Gebäudedämmung building insulation [% rh] [% rh] rh Raum Room [% rh] Mrz 01 Apr 01 Mai 01 Jun 01 Jul 01 Aug 01 Sep 01 Okt 01 Nov 01 Dez 01 Jan 02 Test system: light wall construction: isothermal calculation Thermo technical investigation by construction physicist - no effect on the heat transfer through the mounting points Stationary calculation: shows the effect of the mounting points and the wall materials over the temperature zones

8 Test system: heavy construction Inside Innen Outside Außen Clay brick 250 mm Ziegel, 250 mm Back of collector, 6 mm Kollektorrückwand, 6 mm Mineral wool insulation, 50 mm Absorber Collector glass Temperature and humidity sensors in every layer Collector mounting heavy construction Photos: GREENoneTEC

9 Test system heavy construction Heavy construction 25 cm clay brick 750 litres domestic hot water tank Photo: GREENoneTEC Heavy construction, temperature, Nov Temperature [ C] Temperatur [ C] T Zwischen between absorber Absorber and glass und Glas T nach behind Absorber absorber 120 T nach behind Kollektorrückwand back of collector 110 T nach behind Kollektordämmung collector insulation 100 T Innenwand inner wall Start of operation mid November

10 Heavy construction: isothermal calculation Variant analysis brought optimal solution Stationary calculation: shows the effect of the mounting points and the wall materials over the temperature zones Summary light construction The are no essential thermal losses due to the mounting of collectors with wooden frames Dry materials preferable during the construction (construction wood or massive wooden plate, dry heat insulation) Foil open to vapour, sealed to air drying of the construction to the inside Wall heating is always seen positively

11 Summary heavy construction Back of collector good insulation material (wood, if possible) Drainage layer between collector and building Thermal separation between mounting points and wall Drying of the outer wall towards the inside Wall tiles on the inside reduce the drying process Minimum insulation between collector and bricks (collector insulation): 8 cm to prevent summer over-heating in room Wall heating is always seen positively Making solar panels more attractive / accepted Coloured solar varnish: Low-cost selective solar absorber Colour for a better acceptance Suitable for different absorber materials Independent of the absorber geometry Also applicable by collector manufactures

12 Colour absorbers vs. selective coating Efficiency factor Test collectors with Cu-absorbers, collector angle 45 with 800 W/m²

13 Collector area enlargement The collector area of coloured absorbers must be increased by 20-70% compared to absorbers with selective coating. The area enlargement is smaller for combisystems than for domestic hot water systems. System Solar fraction [%] Solar varnish to selective [m²/m²] Green/blue to selective [m²/m²] Red/brown to selective [m²/m²] Single family house, 4 persons, hot water preparation Single family house, 4 persons, hot water preparation and 8 kw heat load Coloured absorber Photo Mayer

14 Multi-family houses new building Photo: AKS DOMA Multi-family houses new building Ried im Oberinntal, Austria

15 Multi-family building retrofit Photo: Schüco International KG Multi-family building retrofit Photo: Schüco International KG

16 Multi-family building Integration into balconies Photo: Siko Business establishments Collector area 87 m² Covering strip aligned with architecture Window outer shading run in the collector covering strip

17 Further information on integration Thank you for your attention! Charlotta Isaksson AEE INTEC Feldgasse 19, A-8200 Gleisdorf Photo: AKS DOMA