High-Efficiency Exterior Insulation and Finish Systems: R-30 Walls in Three-Inch Thickness-Modeling, Performance Testing, and Installation

摘要

Fumed silica vacuum insulation panels (VIPs) have been known to provide excellent thermal insulation due to their extremely low thermal conductivity. VIPs are more fragile than conventional insulation and do not lend themselves to usage under typical jobsite conditions. An innovative way of incorporating VIPs into a 3-in.-thick wall cladding system was developed over a multiyear period through the U.S. Department of Energy (DOE) program DE-EE0003915. Initial performance testing of an exterior insulation and finish system (EIFS) utilizing VIPs was completed at Oak Ridge National Laboratories. Thermal performance was validated by using a heat flux meter (ASTM C518) and two hot box tests (ASTM C1363). Based on the results, THERM? 5.2 and WUFI modeling were performed to determine optimum design. Field trials were completed on a retrofit project in a northern climate that resulted in delivering an R30 wall in a 3-in. thickness. The field trial further improved on the designs tested and modeled. The system uses drainage EIFS construction methods with the exception that the layout of insulation is engineered and sequenced. The wall system was then taken through further testing to ASTM E119, ASTM E330, NFPA 285, and NFPA 268 standards, to which all results were positive, rendering a code compliant commercial grade system. Thermal resistance performance values from R-24 to R-40 in a 3-in. overall panel thickness are demonstrated using Type 2 expanded polystyrene (EPS) insulation and varying the thickness of the VIP within the EPS. Installation of batt insulation within the steel stud cavities demonstrated an upgrade of R5. This high-efficiency wall cladding system will deliver top performance in a thin wall system not seen before in commercial construction in North America.