Details on Enveloping Surfaces

Information on the Enveloping surface dialog in the dynamic cooling load calculation.

The enveloping surfaces should be recorded as completely as possible in order to take into account all those building masses that contribute to the exchange of thermal radiation.

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Module overview ➤ Cooling load dynamic ➤ Room level ➤ Enveloping surfaces

Table

Abbr.

Abbreviation for the component. You can use the familiar LINEAR Buildingabbreviations:

  • EWA: Exterior wall

  • EWI: Exterior windows

  • ED: Exterior doors

  • RF: Roof

  • RW: Roof window

  • CL: Ceiling

  • FL: Floors (also in adjoining to ground)

  • IWA: Internal walls

  • IWI: Internal windows

  • ID: Interior doors

  • DAR: Deduction areas

Orientation Abbr. /°

The orientation of the respective component. The orientation can be selected from the drop-down list or specified in degrees.

adjoining to

Indication of the thermal conditions on the other side of the component. Possible inputs:

Abbr.

Meaning

Possible for these components

e

external: adjoining to outside air

EWA, EWI, ED, RF, RW, FL

g

ground: adjoining to ground

EWA, FL

i, j

Adjoining heated adjacent rooms

IWA, IWI, ID, CL, FL

i,i

Area adjoins this room on both sides (e.g. room divider)

IWA, IWI, ID, CL, FL

Qty.

Quantity of a component that exists. If there are several identical components, you can enter the number here.

Gradient °

Gradient of the component relative to the ground. The gradient influences the diffuse and direct radiation on the component.

α outside

The absorption coefficient describes the absorption capacity of opaque exterior components for short-wave solar radiation. For windows and other transparent exterior components, the value is 0. For exterior walls, the value 0.80 is suggested by default.

ε exterior

The emission coefficient for long-wave radiation describes the ability of exterior surfaces and exterior components to absorb and re-emit long-wave radiation from the environment. For windows, the suggested value is 0.92. For exterior walls, the value 0.80 is used by default.

b m, h/l m, A m2

Width, height, length and area of the component. When you enter the individual dimensions, the area is determined automatically. Alternatively, you can enter the area directly.

U W/(m2K)

The U-value can be entered directly as a numerical value for windows and interior doors, as these are particularly lightweight components with low mass and heat capacity. For all other components, the exact layer structure is required with details on density, thermal conductivity, lambda and specific heat capacity.

T(amb) °C

The ambient temperature for the respective component. For exterior walls, the outside temperature is automatically entered from the climate data.

Adiabat

For interior walls, Adiabat (symmetrically loaded) is automatically suggested. The assumption is that the radiation and the heat flow of the side facing away from the room correspond to those of the inside. The wall radiates in equal parts into the room and into the adjacent room.

Preset-temperature: You can enter a constant temperature manually.

Attention:

The VDI core combines similar components for the calculation. Therefore, for rooms with only interior walls, a constant temperature (for the rear side) must be specified for at least one wall so that the core has a reference against which an exchange can take place.

General temperature profile set: You can also assign a general temperature profile set to a component, or select a different profile or create a new one by clicking Add/Change. The effects of radiation on the inside of the wall are assumed for the back of the wall and mirrored, as with Adiabat (symmetrically loaded).

Glass %

Glass area in percent. Here only the glass area is meant, i.e. window area minus the frame area.

Window values: The assigned window configuration. From the drop-down list you can assign existing configurations, or click Add/Modify to create a new configuration or modify an existing one.

PHC: Drop-down list to select the panel heating/cooling for this component. Clicking Adjust options ... opens the Component properties for panel heating/cooling dialog, where you can adjust settings for the dimensioning of panel heating/cooling.

Show or hide columns : opens a list where you can show or hide columns of the table.

Generate sample areas

If you do not yet have any concrete information on the enveloping surfaces, you can have standard area generated automatically in order to make initial rough estimates.