Hygrothermal Simulations and Analysis of Solar-Driven Inward Water Vapor

This report describes a hygrothermal analysis of wall assemblies constructed with stone wool (also known as rockwool) continuous exterior insulation in DOE climate zones 1 to 4. Hygrothermal analysis of these wall assemblies was conducted with WUFI® Pro 5.1. WUFI is a transient heat and mass transfer model which can be used to assess the heat and moisture distributions for a wide range of building material classes and climatic conditions. Hygrothermal modeling is used to determine the moisture-related durability risk, including wetting and drying due to vapor transmission through the assembly materials from the interior and exterior. In this particular study, the analysis is focused on the risk of solar driven inward vapor in the enclosure assembly.

The objective of this analysis and report is to develop recommended wall systems when using high vapor permeance continuous stone wool exterior insulation in different climate zones. When found, limitations or systems that are not recommended are also noted.

Note: This report was prepared for ROXUL Inc. and is published with permission.