Visualization for the Drying Effect, the phenomenon that’s happen behind Non-Permissive Insulation.

The Drying Effect The best reveal of the Drying Effect is when Vapor-Impermeable (Non-Permissive) Insulation is installed Inside of a building. A classical wall, inside vapor-permeable insulated will experience the worst mold growth in the non-ventilated spaces, hidden inside the walls. Creation: Present a concrete slab 12cm, on the last floor of a building. Interior applied, construct a metal stud structure. Install in the cavity mineral wool, 20cm. Complete the cavity by installing gypsum-board, finish the interior. Apply on the interior a comfortable temperature 21C (70F) and on the exterior -18C (0F). Show the temperatures by color. Show a front of warm air starting with 18C (65F) temperature from the back of gypsum board (inside to cavity surface) and a front of cold air with -12C (10F) temperature starting from the interior surface of concrete slab. Those fronts of air with differences of temperatures moves fast inside cavity, loop the insulation or go through it, and fast change energy by convection. Represent the vapor flow (maybe as fog) that passes through gypsum board and mineral wool. Show the occurrence of condensation on the surface of concrete slab and the formation of mold on the surface and in mineral wool. Point out the permanent dew point on the back of permeable insulation. Show the mold spores that affect house occupants. Take off the metal stud structure, mineral wool and gypsum board and throw it away. Install instead Non-Permissive Insulation, with the process of installing (I’ll give you more details). Insulation is 8cm or 3inch. Complete the interior with mesh and cement-mortar, finish the inside. Apply again the differences of temperature. Show vapors that doesn’t pass through the Non-Permissive Insulation (the fog stays inside, constant humidity). Show and marks the dew point of warm vapors as a plane inside NP Insulation. Vapors doesn’t get to the dew point so there is no condensation. A slow thermal flow passes through NP-Insulation, and rises the temperature right behind insulation. The small thermal flow warms vapors behind insulation and creates a difference of temperature from exterior cold vapors. This difference of temperature make vapors to migrate to exterior. Highlights the avoiding condensation and Drying Effect versus condensation, mold and degradation.