A2PBEER Affordable and Adaptable Public Buildings through Energy Efficient Retrofitting TECNALIA. Amaia Uriarte

Transcription

1 A2PBEER Affordable and Adaptable Public Buildings through Energy Efficient Retrofitting Train the Trainer Workshop September 2016, Bilbao TECNALIA Amaia Uriarte Eneritz Barreiro External Ventilated Façade

2 External Ventilated Façade 2

3 Content of the Presentation Overview The need for the Technology. Main design features of the Technology. Description of the main benefits level of innovation, energy savings etc. How and where the Technology can be used for retrofitting. Evaluation Benefits of retrofitting the technology energy savings, costs, ease of installation, uniqueness etc. 3

4 Overview Conventional thermal insulation materials : rockwool, polyurethane polystyrene based foams, mineral wools, fibres and even materials such as cork, hemp, perlite. Their common thermal conductivities W/mK, being the lowest value W/mK for the polyurethane. In building façades insulation material are integrated as multi layer solutions or composite materials. Applied thickness depends on the thermal transmittance requirements /thermal resistance of all National building codes. The U requirement, the insulation thickness 4

5 Vacuum insulation panels (VIPs) can defined as an evacuated foilencapsulated open porous material as a high performance thermal insulating material (Baetens,2010a). Their thermal performance is three to six times better than still air, i.e. thermal insulation principle of traditional insulation materials and is achieved by applying a vacuum to an encapsulated microporous material. High performance thermal insulation materials that can achieve high thermal energy resistance, with a low thickness has become a technical challenge 5

6 The need for the Technology. The requirement to reduce buildings use and cost of energy in the last years, has lead to increase the applied insulation thicknesses. Since the approval of EPBD EU2010/31 recast,the thickness of the prescribed insulation has almost doubled, contributing to increase floor occupancy and the complexity of the construction details. Facade walls Opaque component U value high U value low Country (W/m2 K) (W/m2 K) Climate zones 1 Austria Dfb 2 Belgium Flanders Cfb 3 Bulgaria Csa, Dfb 4 Croatia Csa,Dfb 5 Cyprus Csa 6 Czech Republic Dfb 7 Denmark Cfb,Dfb 8 Finland Dfb, Dfc 9 France Csa, Cfb, Dfb 10 Germany Cfb,Dfb 11 Greece Csa, Dfb 12 Hungary Dfb 13 Ireland Cfb 14 Italy Csa, Dfb 15 Latvia Dfb 16 Lithuania Dfb 17 Luxembourg Cfb 18 Malta Csa 19 Netherlands Cfb 20 Norway Dfb, Dfc 21 Poland Dfb 22 Portugal Csa 23 Romania Csa,Dfb 24 Slovakia Dfb 25 Slovenia Csa, Dfb 26 Spain Csa, Cfb, Dfb 27 Sweden Dfb, Dfc 28 United Kingdom Cfb U wall = W/m2K Insulation thicknes for different U values λ Thickness Thickness Thickness for U (W/m for U for W/m 2 K(cm) K) 0.75 W/m 2 K (cm) W/m 2 K (cm) Rock wool EPS graphited Super insulation VIPs the use of new materials with high thermal performance that provide low thermal transmittance values in low thickness has become a technological challenge 6

7 Main design features of the Technology. VIP panels protected with rubber PVC clip supporting VIP Aluminum anchorage Thermal pad Aluminium T profile PIR M insulation Cladding (ceramic) 7

8 Description of the main benefits level of innovation, energy savings etc. With 3cm of VIP integrated in Bucthtal s ventilated, is possible to achieve: U FV = W/m 2 K included ψ 2D and χ 3D of joints and anchorage Keep the hygrothermal properties of the ventilated façade Protruding : 10cm to the exterior 8

9 Description of the main benefits level of innovation, energy savings etc FINAL SOLUTION BUCHTAL KeraTwin K20 solution: VIP Panels: nominal dimension 1100x600mm; thickness (30 mm) + rubber (3+3 mm, only on VIP large faces) + silicone like material 2mm thick to protect VIP edges PVC clip supporting VIP panels (lenght as the VIP panel), H profile (central thickness 5mm, lateral thickness 3mm) additional continuous vertical PIR M insulation (nominal cross section 40x36mm) Supporting structure L 40/80/150mm aluminium profile, thickness 4mm, with thermal pad T profiles (2mm) Cladding extruded ceramic tiles 9

10 1 VIPs PANELS 10

11 2 PVC CLIP 3D printed and extruded clip supporting VIP panel installed on Demonstration Wall confirming proper clip construction Special profiles 11

12 3 PIR M insulation Since VIPs are vapour tight, in order to avoid any interstitial water building up, PIR insulation is included in the vertical VIP VIP union. 12

13 4 SUPPORTING STRUCTURE Thermal break elements between the L bracket and the existing wall to reduce the 3D thermal bridge. 13

14 5 CLADDING Because of their hygrothermal properties compared to open joint solutions, it was decided to used extruded ceramic panels with overlapped joints. Main feature of Keratwin K20 type of cladding, is its flexibility and possibility to obtain varied lengths of ceramic panels (up to 1800mm). It allows troublefree installation of cladding regardless of VIP panel configuration. Thickness of ceramic panels is equal to 20mm; panels are manufactured in varied heights from 200mm to 500mm, the height depends on horizontal arrangement and wind loads on the façade. 14

15 How and where the Technology can be used for retrofitting. This design can be implemented in all types of buildings, like a common ventilated facade 15

16 Benefits of retrofitting the technology energy savings, costs, ease of installation, uniqueness etc. Excellent thermal properties thermal conductivity λ=0,005w/mk The insulation thickness lower in comparison to other systems 30mm instead of 200mm The system is easy to install PVC clip integrating VIP into ventilated facade Internal: Significant internal floor space savings System can be incorporated with existing and future elements & services without affecting thermal layer 16

17 Evaluation VIPs are integrated in the façade system. These materials are highly insulating, this implies that any thermal bridge will produce a relatively larger effect than in its counterpart with traditional insulation materials. This required of a detailed thermal assessment of the proposed architectural designs. Thermal performance The envelope material in the VIP is air and water tight (it is designed and manufactured to keep vacuum pressure within the VIP). The laying of a watertight material all over the façade has been frequently identified with condensation problems, not only surface, but also interstitial condensation. Condensation performance The following performances have been verified: Thermal performance One dimensional U value, according to EN ISO 6946[2]. 2 3 dimensional U value, when considering multidimensional heat transfer. Solar heat gain coefficient (g equivalent for opaque envelope) Condensation performance Indoor surface condensation & mould growth risk. Interstitial condensation Overall mechanical performance of the façade 17

18 K20 Solution Global heat transfer coefficient: U, ψ, χ units Representative area, length or units U 1D VIP W/m 2 K m 2 Comments U 1D PIR W/m 2 K 0.42 m 2 34 mm thick PIR ψ 2Dclip W/mK 16.5 lm Without silicon prot. ψ 2DPIR W/mK 10.5 lm 34 x40mm/lm sizepir χ 3Dbracket s W 11 6 mm thermsotop Uglobal W/m2K m2 Methodology EN-ISO

19 COMPARISON OF CALCULATED THERMAL AND HYGROTHERMAL FEATURES OF VENTILATED FAÇADE DESIGN WITH TARGET VALUES Targeted values for the external facade system Thermal transmittance targeted U factor < 0.25 W/m 2 K Water vapour diffusion: the façade has to allow the internal wall to breathe. Thermal bridges: overall thermal bridges related to the anchoring of the system should be less than the 15% of the equivalent thermal value of the panel. Calculated values U =0.276 W/m 2 K No water condensation breathable façade system When considering only 2D thermal bridges, U value increases 34% when the PIR is considered a thermal bridge by itself. When the PIR is considered in the 1D model, 2D represent 22% and in the overall model, ie considering 2D and 3D, thermal bridges represent almost 50% of the thermal transmittance, being anchorage one of the key elements in improving the behavior. 19

20 PROTOTYPE installation 20

21 PROTOTYPE installation 1. Condition the existing wall. All ducts, pipes, wires, gutters should be removed and any imperfection or damage in the existing façade should be repaired before starting the façade installation. 2. Draw the lines where the profiles and anchorages should be installed according to the façade layout drawings and plans. 21

22 PROTOTYPE installation 3. Place the fixed point brackets that withstand the façade weight in the slabs with a thermal break between the aluminum anchorage and the existing wall neoprene according to the façade layout drawings. 4. Place the moving point brackets with the thermos top layer. 5. Install the vertical T and C aluminum profiles so the top part of the T profile is around 90 mm from the bracket or around 95 mm from the façade. 3 &

23 PROTOTYPE installation 6. Begin installing the insulation layer from one of the external extremes of the L brackets. 7. Cut PVC profiles to proper length equal to VIP panel length (if longer) 8. Begin installation with starting clip (L shaped) from the bottom of external wall. Use 3 to 4 mechanical fasteners adequate to external wall construction to fix first part of the clip. 9. Place the VIP panel on fixed element and snap second part of clip together with the fixed one to hold down VIP panel. 23

24 PROTOTYPE installation 10. Place the first part of the clip on mounted VIP panel and fix it to external wall. 11. Repeat steps At the edges of external wall like upper edge of wall, openings, etc. use a final clip use starting clip. Where VIPs can not cover the whole area, use PIR insulation. Maximize area covered with VIPs in order to reduce thermal bridges or areas with lower insulation levels. 24

25 PROTOTYPE installation 13. PIR installation in top of brackets: measure the distance between two VIP in the vertical arrangement. Cut a piece of PIR of 8 cm thick that fits within. Introduce the PIR in the gap and seal it with a strand of polyurethane. 14. Cladding: install the cladding fixed between the pawls. 25

26 PROTOTYPE installation 26

27 PROTOTYPE installation 27

28 PROTOTYPE installation 28

29 PROTOTYPE MOUNTING VALIDATION AND RECOMENDATION No vacuum loss was observed in the reception VIPs. Apparently, no vacuum loss occurred during the installation. VIPs were handled with relative care. Small displacements of the asphalt layer were observed in some of the VIP panels, hampering the continuity of two VIP panels in the wall. The protruding asphalt layer was cut with a sharp cutter External rubber coat seemed easily detachable 29

30 PROTOTYPE MOUNTING VALIDATION AND RECOMENDATION two layers of fumed silica that are in the interior of the envelope are not perfectly straight PVC clips should be fixed to the existing façade by means of mechanical fixation. For concrete, brick façades plastic wall plug. PVC clips have to be predrilled. 30

31 Thank you for listening! This project has received funding from the European Union s Seventh Programme for research, technological development and demonstration under grant agreement no The information in this presentation does not necessarily represent the view of the European Commission. 31