Details on Transmission

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Module overview ➤ Heat load ➤ Room level ➤ Transmission

General room data

The upper part of this view shows the room number, the room name, the set room temperature for heating case and the dimensions of the room (the latter not in cases where only the area was given). Room number, room name and room temperature can be edited directly, the room dimensions only after clicking .

Tooltip above room temperature

If a standard-compliant temperature has been defined centrally for all rooms in the location and climate data, the notification Room temperature according to selected standard is displayed here as soon as you hover the mouse over the field.

If you have deactivated the option Inside temperatures according to standard at the project level and the selected room temperature corresponds to the standard temperature of the selected room type, the note Room temperature corresponds to selected standard is displayed as soon as you hover the mouse over the field.

If you have deactivated the option Inside temperatures according to standard at the project level and the selected room temperature does not correspond to the standard temperature of the selected room type, the note Is freely agreed is displayed as soon as you hover the mouse over the field.

Three-dot button behind the room temperature

Click on to open the table with the temperature variables. The table can be edited in the master tables and supplemented with user-defined values.

Intermittent heating operation

Opens the Intermittent heating operation dialog, in which you can enter information on the additional heat-up capacity.

Heat transfer system for rooms higher than 4 m

For rooms higher than four meters, select the type of heat transfer system from this drop-down list in this room to compensate for any deviating surface temperatures on components.

Table with component data

By clicking you have the possibility to copy the contents of the table with or without column heading and paste it into Excel.

If you have selected individual rows or cells, you can copy the selected data with the key combinations Ctrl+C (with column heading) or Ctrl+Shift+C (without column heading) and paste it into Excel, for example.

With F5 you can insert a new line above the currently selected line and with F6 you can delete selected lines.

: Opens a drop-down list that allows to specify which columns of the table are displayed.

Abbrev. of ID - Abbreviation number Abbreviation for the type of component. The software differentiates between predefined components from the master tables and component types. The predefined components are defined in more detail via the numbering and can already contain U-values and dimensions. Predefined components can be adjusted in the master tables.

You can enter an abbreviation for the type of component or a component directly in the column. Alternatively, you can select a component or a component group from the table by pressing F8 or by clicking . The following component types are available for selection:

OR - Orientation: Cardinal point in which the component or area is located. It is used to identify the gross area and, in the case of the GEG/EnEV, also to determine the solar heat gains of exterior windows, transparent insulation and glazing (winter gardens). Deduction areas are not given a cardinal point. Instead, these areas are marked with -- as deduction area (a "-" is sufficient as input). The specification H (horizontal) can be used for ceilings, floors, roofs and roof windows. The compass direction can be overwritten manually for components that were entered from CAD. A manually adjusted compass direction is displayed in bold and can be reset to the original value by deleting the manual value. A manually adjusted value is not overwritten when synchronizing with the model.

N - Number of equal areas: The number of equal areas is a multiplier. The input is limited to whole positive numbers without decimal places. If areas are to be considered only partially, the values of the Width and Height columns can be adjusted accordingly.

W - (max.) Width, h/l - (max.) Height or (max.) Length, A - Area, A’ - Net area:

When creating building structures in LINEAR Building:

In these four columns you define the width and height/length or area of the heat-transferring outer area. If the width and height or length is entered, the surface area is calculated from the data. If the area is entered, the entries for width, height or length are deleted. In column A’ the area minus all deduction areas is displayed.

In these fields it is possible to enter dimensions as a term. Enter the term e.g. with 2.25+1.35 and press Enter. The result is calculated and entered. For areas that are to be only partially included in the calculation, such as gable walls, the dimensions can be entered with an appropriate factor (e.g. 0.5*width*height for triangular areas).

When transferring building models from Revit and AutoCAD:

For AutoCAD building models that are not based on a linked IFC architecture (3D - IFC link workflow), the values for b and h/l are not output if their product is not equal to the area A.

If your project is based on a building model that was detected from Revit or was created from AutoCAD and is based on a linked IFC architecture, the maximum dimensions determined from the model according to the corresponding standard are always output in the two columns b and h/l, even if the product of b and h/l does not correspond to the area A calculated according to the standard.

In the column A’ the surface area minus all deduction areas is displayed.

P Outline (Perimeter) of the floor plate adjoining the ground: You can enter the perimeter P only for floors adjacent to the ground.

If the U-value of the floor is ≥ 0.5 W/m²K, the perimeter P and the depth of the bottom plate are required to determine the equivalent coefficient of heat transmission of the bottom plate (Uequiv,k) in addition to the U-value of the component. The parameter B' required for the determination of the equivalent U-value is calculated from the exposed perimeter P and the area A_g.

As a proposal, the full perimeter of a rectangle is calculated.

With the function key F9 or you can pick up the perimeter directly from the CAD program if a CAD connection exists.

If the U-value of the floor is < 0.5 W/m²K, the building data is used for the calculation and the input of the perimeter is omitted.

U-value: The physical U-values are calculated according to DIN EN ISO 6946. Enter a U-value directly as a number, or press F8 or click on to select a previously calculated U-value from the list. In the master tables you can create new components, have their U-values calculated or enter and save them directly.

Z - Depth of the bottom plate below ground level: For the area combination FB g (floor in contact with the ground - floor plate) and AW g (exterior wall in contact with the ground), the depth of the floor plate below ground level z is also queried in m. Depending on this depth, the U-value of the component is adjusted via the floor plate or exterior wall in contact with the ground.

U(tb) - Thermal bridge supplement If no detailed thermal bridge loss coefficients are available for all components, the simplified method described in the standard is used to determine the transmission heat losses. You can define a thermal bridge supplement category for each component by clicking . In the dialog that opens you can also define your own categories. For building components facing heated rooms, the thermal bridge addition is disregarded.

Uc/Ueq – Corrected U-value: Shows the corrected U-value according to the thermal bridge effect for components with heat losses to the outside or to unheated rooms. For areas adjoining the ground, the equivalent heat transfer coefficient Ueq over the ground is displayed.

Adjoining to: Shows the room adjacent to the selected component. This information is determined during the building detection and entered here. Pressing F8 or clicking opens a context menu with the following options:

• heated room

• unheated room

• other building

• this room

• Other room...

After clicking Other room... you can select another room from a list of rooms in the project. Entry option via abbreviations is still possible:

t - adjoining temperature and Summand f1: The input option depends on the combination of abbreviation (Abbrev. of ID) and the identifier adjoining to. The standard outside temperature is automatically entered for components that directly contact the outside air. The input is deactivated in this case. Even if adjacent rooms belong to other building units, the entry is deactivated. For generally heated or unheated rooms, the fields are activated and different values are proposed depending on the adjacent room: If the adjacent room is not in the project, the corresponding predefined temperature from Tool bar ➤ Configuration ➤ Heat load is entered for the adjacent temperature. If the room is in the project, a steady-state heat balance is calculated from the room components of the adjacent room that are not adjacent to unheated. Both fields can be adjusted manually. The respective other value is calculated from the input. A correction factor of 1 in the column Summand f1 means that the heat loss of the building component occurs directly to the outside air and that the transmission heat loss is taken into account to 100%. In the Adjoining temperature field, press F8 or click Temperaturesdialog, where you can select one from a list of predefined temperatures. In the Summand f1 column opens with F8 or click a dialog where you can select correction factors for unheated secondary rooms from a list.

h_U - Absolute height of the lower edge of the room component: The value is used to calculate the mean height of the room components and refers to the height of the ground floor. The average height of the room components is required for the calculation of the surface temperature of the room components, which is required for the temperature correction factor for rooms with greater height (summand f2). This column is hidden by default. You can show the column via the drop-down list, which is opened by clicking on . The value can be overwritten and is then displayed in bold. Delete an entered value to restore the original value.

When a building is transferred from a CAD program, the values are also transferred. For projects whose building structure was created manually in LINEAR Building, the values are derived from the absolute height of the lower edge of the room (Height lower edge). The Lower edge height is used for all room components except ceilings, roofs and windows. For ceilings, roofs and skylights, the room height minus the ceiling thickness is also taken into account. For interior and exterior windows, the floor thickness and the parapet height are also taken into account.

Summand f2: Temperature correction factor for rooms higher than four meters. This is not an entry field.

HTL, Φt: Heat loss coefficient of the component HT in W/K and in the column Φ t the transmission heat loss ΦT in W. These are no input fields (except for Z = additional load)