b06 - Construction design VF-AL

Introduction

The present guideline seeks to describe the main components and the general installation procedure of the BIPV ventilated façade designed for the Zamudio (Spain) demo site in the frame of BFIRST project. Nevertheless, the components, materials and their installation process may vary in different cases, thus the information provided in this document should be handled with care, adjusting the installation with regard to the existing wall composition in each case. The aim of this guideline is not focused on the installation process of the BIPV modules, but the construction process of the substructure needed to install them. The selected structure for the VF-AL BIPV module is based on two extruded aluminium profiles that support PV module and an aluminium sheet. Aluminium profiles are 2 mm thickness, and the geometry has been designed for an easy installation of several façade units by connecting the last profile to the next one. In addition, an aluminium sheet increases the structural properties of the system and PV panel stability, where several adhesive points along the central channel joint the module and the sheet. Also several holes have been done where module junction box is located in order to let the electricity output wires be connected from one module to another. Total weight (modules + mounting system): 60 kg/m2. Components description (details)

Aluminium profiles (in black) role: Main support for the BIPV modules and aluminium sheet

Characteristics: material thickness: 2 mm material: aluminium

Aluminium sheet (in blue) role: Structural support for PV module

Characteristics: width: 337 mm length:- mm material thickness: 2 mm material: aluminium  

Calculation Hypothesis

The installation shall be performed following homologations and mounting instructions. The dimensioning of the substructure shall be calculated based on the BIPV module dimensions, its anchoring system and the composition of the wall where it is intended to be installed.

Wall conditions:

  • Prior to the works, it shall be verified by means of mechanical tests whether the assumptions made on the resistance of the base material are correct. If the base material is steel, attention should be paid to the galvanic pair between the aluminum profile and the steel base (corrosion)
  • In case of masonry wall and deck or slab edge fixation, the bracket must directly lean over the concrete, and if necessary the exterior coating will be removed.
  • HILTI’s substructure for ventilated façade is designed to withstand its own weight, the weight of the BIPV modules and wind loads. The substructure is not designed to enhance the stiffness or support the base material. In all cases, the technician responsible for the project must assess that the wall has the required stability to withstand the new loads due to addition of the ventilated façade.

Wind loads calculation:

  • Load considerations related to the action of wind shall be performed following Eurocode 9: Design of aluminum structures

Anchors:

  • Load values of anchors correspond to the values provided in their homologation.
  • Attention should be given to the sort of materials in contact between brackets and anchors to avoid galvanic corrosion.
  • Mounting instructions of anchors must be respected.

Fix points and slide points:

  • The execution of fix and slide points shall be performed following technical specifications and installation instructions given by HILTI. (structure supplier)
  • The execution of fix and slide points shall be conducted free of stresses.
  • The number of fix and slide points shall be fulfill the specifications given in the mounting drawings.
  • Self-drill screws used in slide points shall allow the movement of those points

Keil anchors:

  • Keil anchors are not calculated nor provided by HILTI. See d06 Mounting and installation.