WUFI

Double vapor retarders sometimes seem to work, but in real life you never have a perfect scenario where only vapor diffusion occurs. Thus you should always test your structure for some water ingress.... that is where you see the catastrophic effects of double vapor retarders. By using a vapor imperm...

Rain screen walls most of the time are designed to provide equal pressure between the exterior facade and the air space. Therefore in theory negating the pressure driven moisture flows. They do not rely on air flow movement. They are vented not ventilated systems. Therefore they have less air flow c...

What type of stucco are you using ? what is the capillary saturation moisture content of this stucco ? Is that what is used in San Francisco ? Stucco is an absorptive cladding, as such why would it not have a high relative humidity at the interior side of the stucco ? If you have an answer to the ab...

Hi Lizzy, WUFI 3.2 is a 1-D version. All material properties should be identical other than in 2-D, the x- and y- cartesian coordinates can have different transport properties for the thermal transport. The sorption and suction isotherms are exactly the same. I still think you can analyze the wall e...

Lizzy, You will need to approximate your steel element with another material. Selecting one is tricky but for steel that should not be such a problem. The issue is that WUFI 4.1 is 1-D model, and your steel frame system is not usually a 1-D problem. However what you can do is run cases with and with...

Within the WUFI material database there are various concrete materials available for selection. If I want to model a building that has a 6" thick architectural precast skin, do you have any recommendations as to which concrete might provide the best simulation of this type of material? Q1. Can ...

Q1. You should create a new material if metal is not available. Q2. In the next version of WUFI you can handle the ventilation aspects. As a very conservative approach I would model the wall with and without the metal panel system. For the system without the metal panel, I would turn off the wind dr...

The performance of vinyl depends on the type of vinyl system used(manufacturer dependent) . The type is dependent on the level of air tighness and amount of retention of liquid water at the back joint of the vinyl assembly. Suggestion is to create a new material based on these two paramters. WUFI ca...

Hi Charles,

As far as the foil faced membrane, please use another membrane with the same vapor permeance. Radiation transport is not considered within the wall structure, except within the air layer.

Achilles