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U-Value Tool Joint U-Value |
  
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U-Value Tool Joint U-Value |
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Description
With the U-Value tool Joint U-Value you can calculate and display Joint U-Values according to EN 13947.
How do I activate it?
The U-Value tool can be activated with the command U-Value of the menu Results or by clicking on the 
icon in the Toolbox flyout. Then select Frame UTJ-Value as kind in the tool properties (cf. figure 2).
Click with the tool on the result object for which the Joint U-value should be calculated. Unlike to the Uf-value the given construction including glazing and spacer is analysed.
Then the frame materials which define the frame measurements have to be determined in the opening dialog window. Consider that these materials should only be used exclusively in the frame. If necessary, you have to create duplicates of materials (e.g. aluminium frame and aluminium panel) and you have to assign them to the according domains on the model page.
Figure 1: Example of a joint U-value object
You can adjust afterwards the calculation kind for the frame width with the selected frame materials (Max of projections, Cold side projection, Warm side projection) as well the frame materials themselves in the Properties flyout (cf. figure 2).
Figure 2: Properties flyout for the joint U-value object
The definition of a joint U-value is explained in detail in tutorial 5.
In special cases, if the frame width can't be exactly defined with the materials (e.g. "Z-Profiles"), you can also adapt the dimension manually by moving the position of the start points of the dimension objects using the Select, Move, Scale tool. You can also change the text positions of the help objects, of the U-values of the base construction and the dimension lines with the same tool.
Defining Styles
The presentation of a joint U-Value object can be selected in the Style list in the tool properties (cf. figure 3). The list shows all styles for joint U-value objects that have previously been determined in the Styles flyout.
A new joint U-value object is always created with the styles currently marked in the Style drop down list. You can either change the selection of the styles in the Styles flyout or select the according style in the Style drop down list of the tool properties.
The styles can also be adjusted afterwards by using the Assign Properties tool or by using the Drag&Drop function (cf. tutorial 1).
The joint U-value is calculated according to EN 13947 as follows:
Figure 4: Calculation of a joint U-value
with:
Φ: Total heat flux in to or out of the model [W/m]
ΔT: Temperature difference [K]
Ug: U-Value of the panel or glazing [W/m2K]
bg: Width of the glazing or the panel [m]
bf: Width of the frame [m]
If the calculated construction is a mullion or a transom, than 2 glazing or panels are used, the formula is as follows:
Joint U-values can only be calculated for constructions, which are recognized as window frames according to EN 13947:
| • | Materials which defines the frame dimension can occur exclusively in the frame (if necessary, you have to create duplicates of materials). |
| • | There are exactly 2 air temperatures on the boundary conditions. |
| • | There are exactly 2 adiabatic boundary conditions ("Symmetry/Model Section" ) each one on both model sections. |
| • | Either it's a horizontal or a vertical window |
Url: http://www.infomind.ch/bph/de/flixo/manual/version6/index.html?tools_uvalue_utj.htm
