Thermal bridges included in thermal envelope of the building are automatically identified when the analysis is carried out (Results > analyse) from the Air Conditioning tab of CYPECAD MEP, by analysing the elements that have been introduced.
Now, with the 2015.f version, users can modify the linear thermal transmittance and internal surface temperature (this latter parameter is only specified in CYPECAD MEP for Spain) of a thermal bridge.
Having chosen the “View thermal bridges” option (Results menu or 
, button, which analyses the job and displays the edges of the thermal bridges that have been detected), users can edit the values that have been calculated for each thermal bridge by selecting an edge (linear transmittance and, for CYPECAD MEP for Spain, also the internal surface temperature factor). The editing process can be done using the following buttons or using the corresponding options in the “Results” menu:
Displays the calculated values or values assigned to the selected edge (present in previous versions)
Allows users to edit the calculated values or values assigned to the selected edge (present in previous versions)
Copies the values assigned to the thermal bridge of the selected edge (new option):
- Select the edge of the thermal bridge whose properties are to be copied. This option only copies the properties of thermal bridges that have been modified by users, and so has no effect if the edge of a thermal bridge that has not been modified is selected.
- Using the left mouse button, click on the edge of the thermal bridge to which the properties copied in the previous step are to be assigned. Several thermal bridges can be assigned these properties by selecting them one by one.
- Click on the right mouse button to confirm the copy.
Deletes the values assigned to the thermal bridge by users, by selecting one of its edges (new option). This thermal bridge will then have the properties calculated by the program. This option will never delete the values calculated by the program.
The edges of the modified thermal bridges are displayed with a dot at their centre.
When an edge belonging to a thermal bridge which affects two or more air conditioning precincts is selected, for example, at the intersection between the façade and floor slab between two floors, users can only see the edge belonging to the floor which is currently displayed on-screen. Nonetheless, the thermal bridge is being edited, and so the value of the linear transmittance is divided amongst the number of edges the thermal bridge contains. For the aforementioned example, the dialogue box indicates “Linear transmittance (ψ = ψ1 + ψ2)”. Furthermore, if the value assigned to either of the two edges is displayed (using the button), the value that is indicated is half of what was introduced in this case. Both edges , the selected edge and the one belonging to the same linear thermal bridge, are represented graphically with the point that identifies them as an edited edge.
These thermal bridge parameters are defined by introducing their numerical values. In CYPECAD MEP for Spain, they can also be defined by selecting a thermal bridge amongst the types defined in the LIDER library and in CYPECAD MEP for France, users can select a thermal bridge from the library of the RT 2012 code.
For the LIDER library, each predefined type contains a linear transmittance and an Internal surface temperature factor defined by LIDER and can be seen in the selection dialogue box. The values LIDER adopts for each type of thermal bridge only contemplate the geometrical position of the thermal insulation. The materials making up the construction elements are not taken into account, and so the values of the Linear transmittance and the Internal surface temperature factor defined by LIDER are approximate.
