Mold Simulator – Tutorial 4


Calculation of linear thermal transmittance of wall/floor junction



In this tutorial we'll examine the following thermal bridge and compute linear thermal transmittance following the method described in EN ISO 10211 at chapter 10.4:


W: wall

F: floor

G: ground


First we need to correct ground size and place adiabatic areas. As stated in EN ISO 10211:


Following these criteria we'll obtain:


Green areas are adiabatic


Before proceeding with linear thermal transmittance computation, we need to determine floor's transmittance. In order to determine it we'll apply Option B decribed at EN ISO 10211 10.4.3; we need to perform a simulation with the following configuration:



Please note that wall portion above the the ground level has been filled with adiabatic material and wall portion below ground level has been filled with ground material. In folder “Doc/samples/mold_simulator” you'll find a file named example10_floor.mos; this contains the floor simulation:




In order to get the correct transmittance value for the floor you must go to “Simulation” tab, “Flows” (on the right of “Simulation settings”, at the bottom) and:


Now we know that floor's transmittance is 0.2387 W/m²K. Please open example10.mos (in folder “Doc/samples/mold_simulator”), which is the wall/floor junction with all the proper materials applied. As you can see in “Elements” tab (pressing button and clicking on elements):




Everything is set to obtain linear thermal transmittance; simply go to “Simulation” tab. One final note: floor boundary condition's surface resistance is 0.171 (since flow direction is downward) and internal wall boundary condition's surface resistance is 0.131 (since flow direction is horizontal).