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Details on Transmission

Information on the Transmission section at room level.

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Module overviewHeat loadRoom levelTransmission

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.

Intermittent heating operation

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

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:

Component code

Component

EWA

Exterior walls (also adjoining to ground)

EWI

Exterior windows

ED

Exterior doors

RF

Roof

RW

Roof window

CL

Ceiling

FL

Floor

IWA

Interior walls

IWI

Interior windows

ID

Interior doors

Z

Additional other heating load in the room (not to be confused with the additional heating-up capacity).

DAR

Pure deduction area this area is considered to be an opening without any thermal calculation.

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.

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 - Width, h/l - Height and Length, A - Area, A’ - Net area:

In these four columns you define the width, height, length or area of the heat-transferring outer area. If the width, height or length is entered, the 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).

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 Ag.

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

Note:

The perimeter shall include only the lengths of surfaces adjacent to outdoor air, unheated rooms, or the ground that separate the respective heated space from the external surroundings. This is usually not the total perimeter of the area.

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.

Tip:

U-value of windows

When entering the U-values of windows, there is an additional possibility to consider the frame construction of the window. The entry is made in the Master tables under Components, U-Value Calculation2. Window if the Use predefined values checkmark is removed. If you then use this variable in the heat or cooling load, the U-value is determined as a function of the window dimensions.

For heat load calculations according to SN SIA 384/2:2020, in addition to considering the frame construction, you can assign thermal bridge supplements of window components by specifying the Psi values for lintel, reveal and parapet.

Note:

Variable U-value of components with layer composition

If a variable U-value of a component with layered structure is used, the heat load takes into account the heat transfer resistances specified in the general heating load data. This makes it possible to use the same component (e.g. B01) once as an exterior wall (e.g. the south wall in the living room) and once as an interior wall. The correct transfer resistances are automatically taken into account.

The same applies to ceilings and floors, where the heat transfer resistances are correctly assigned according to the heat flow density. The same floor towards a colder room (heat flow direction downwards) has different heat transfer resistances compared to a room with higher temperatures.

The differentiation of a component according to the heat flow direction or the type of use (EW or IW) is therefore no longer necessary when defining the component in the U-value calculation.

Tip:

U-value of a floor adjoining the ground

If the U-value of the floor is ≥ 0.5 W/m²K, the equivalent U-value is determined over the ground in accordance with the standard using the perimeter P (perimeter) and the area of the room.

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

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 if the room boundaries are adjacent to a heated or an unheated room or to the ground or to the outside air. Possible entries are:

Abbreviation

Meaning

Possible for these components

e

external: adjoining to outside air

EWA, EWI, ED, RF, RW, FL

g

ground: adjoining to ground

EWA, FL

u

adjoining to an unheated room

IWA, IWI, ID, CL, FL

ud

Ceiling borders on an unheated attic

CL

us

Floor is a suspended floor panel

CL

ub

adjoining another heated building

IWA, IWI, ID, CL, FL

i,j

adjoining heated adjacent rooms

IWA, IWI, ID, CL, FL

t

adjoining partially limited heated adjacent rooms (PLH)

IWA, IWI, ID, CL, FL

t, T-corr. - adjacent temperature and temperature correction factor: These two fields are firmly connected and mutually dependent. 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 barConfigurationHeat 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 temperature correction factor of 1 means that the heat loss of the component occurs directly to the outside air and 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 field T-Corr. press F8 or click a dialog Correction factors for heated adjacent rooms, from which you can select the respective type of adjoining room and thus the standard-compliant correction factor.

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)