High-Performance External Insulation and Finish System Incorporating Vacuum Insulation Panels-Foam Panel Composite and Hot Box Testing

An exterior building facade system that provides high thermal resistance in a relatively thin profile is proposed. The design concept incorporates insulation modules constructed from vacuum insulation panels (VIPs) within protective thermoplastic foam. These modules can be substituted in place of standard expanded polystyrene panels used in existing exterior insulation and finish systems (EIFSs). In addition to providing some additional thermal resistance, the foam serves to protect the vacuum panels during construction and to provide a surface appropriate for an adhesive joint on both sides of the foam-VIP unit. The Oak Ridge National Laboratory helped optimize the process by measuring the thermal transmission of prototype VIP/foam composites and testing wall configurations in a guarded hot-box apparatus. Two concepts in construction were tested in full-scale hot-box testing in an Oak Ridge National Laboratory facility. The first concept was one of maximum flexibility and VIP protection, and the second was one of minimum necessary protection flexibility but maximum practical performance. The major conclusions of the project can be summarized as follows: (1) It may be possible to develop a wall with an overall performance of R30 or greater with multiple VIP arrangements as shown by heat flow meter and heat flux mapping data. (2) The configurations with the highest thermal resistance are those that maximize VIP coverage. (3) A VIP encapsulated in a foam block, of material similar to what is in use today, could be used as a substitute in an EIFS facade system to gain high thermal efficiency in a thin profile. (4) Infrared imaging shows that fumed silica core VIP panels have a higher thermal resistance than foam insulation only, even in punctured sections.