WUFI

Hello,

I have a small doubt about the WUFI-Bio inputs.

Acording to Sedlbauer (2001), the spores can absorb umidity from both the air as well from the substrate.

Thats why he considers the model spore between two arbitrary condition like in the picture attached, right?

But when we enter the conditions into the Wufi-Bio, importing from the Wufi-Plus, it includes only one row of RH and Temperature. Is this right?

Another question, when Wufi-Plus exports the temperature and RH from the surface of a wall, the RH is calculated based only on the wall surface temperature (and of course the umidity of the interior air)? Or the transport trought and the water content of the wall plays a role?

Thanks for the helping.

Hello,

the picture you refer to is figure 37, right? I've just added the whole picture.

The biohygrothermal model is based on the WUFI calculation to calculate the moisture content of the spore. As far as i know the figure expains that even if the spore touches the buidling material, the hygrothermal boundary conditions at the surface influence the spore, but the the spore not the material. And the sperical spore is converted to this one-dimensional layer structure. It's one set (Temperature and Humidity) of boundary conditions for the spore calculation on "both" sides, respectively the spore septum.

WUFI Plus can do the dynamic hygrothermal simulation of the building components. So the exported component surface conditions (to WUFI Bio, for example) are related to the interior conditions, but also the coupled heat and moisture transport throught the component.

Hi, I'm sorry but I still a little confused. Can you help me?

When you say that the surface conditions (temperature and RH) are exported from the WUFI PLUS, the surface RH means the RH of the thin air layer right in contact with the wall, right? Which results from the interior air conditions, the surface temperature, the storage and transport of umidity through the wall, the ventilation, etc....

So, with this said, and since the WUFI BIO inports only one set of umidity and temperature, can we consider that the model spore absorbs umidity only from the air in contact with the wall, and not from the substrate?

Thanks a lot for your helping.

HI,

WUFI Bio is a post prozess, a one way model. The spore doesn't absorb moisture from the substrate (affect the humidity and temperature in the substrate) . Like in the picture. The spore get the boundary conditions from the layer (or material, or substrate) where you make the mouse click in Animation 1D. If you click on the interior surface, those boundary condition is directly on that surface and this boundary conditions (Temperature and humidity) is simulated regarding the substrate and the interior air.