As an alternative to the normal calculation with self-defined usage profiles, the summer thermal insulation can be calculated according to DIN 4108-2, section 8.4. The climate data and usage profiles used are then defined by this standard, the existing usage profiles and the system technology are ignored. In the ETU simulation (not in the single program Summer Thermal Insulation), the only exception is the Sun protection control, if Sun protection "According to usage profiles" is selected in the input mask.
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Summer climate region
The summer climate region is determined by the location. It determines the climate data set (test reference year) and the target temperature (A: 25, B: 26, C: 27°C), exceeding which counts as overtemperature
Type of use
The type of use (residential or non-residential) can be set under "Building data" in the navigation bar. Among other things, it determines the internal loads (non-residential buildings: only during working hours). The maximum permissible excess temperatures are 1200°h in residential buildings and 500°h in non-residential buildings. Degree hours or °h are the excess temperature in degrees times the time in hours. So if the limit value is exceeded by 2°C for one hour, this corresponds to 2°h. If the limit value is exceeded by 1°C for two hours, this is also two degree hours. When considering the excess temperatures, the operative, i.e. perceived temperatures are decisive, not the air temperatures. The operative temperature corresponds to the average of the air temperature and the temperature of the surrounding walls, because they emit heat radiation.
Sun protection control
If a window has a Sun protection (adjustable in the building data), it can be lowered automatically in case of high solar radiation. The threshold values for this can be taken from DIN 4108-2 - for residential buildings 200 W/m² when facing north and 300 W/m² otherwise, for non-residential buildings 150 W/m² in the north and 200 W/m² otherwise. You can also use "Manual" to define a fixed day profile (for non-residential buildings this is only valid on weekdays, no Sun protection is activated at the weekend). Alternatively, the sun protection control can be taken over from the usage profiles.
Passive cooling
Passive cooling can be provided in the building, the maximum cooling capacity of which is entered here. The maximum cooling capacity is entered here. It is distributed to the rooms according to the demand in the individual hour, i.e. rooms with higher cooling demand get more.
Ventilation
The air exchange can be increased by opening the windows during the period of stay, when the room becomes too warm and it is cooler outside (increased daytime air exchange up to 3/h). At night there must also be appropriate possibilities for increased ventilation (up to 2/h with window ventilation). The high night ventilation (up to 5/h) requires ventilation possibilities across floors. Depending on the dimensioning of a ventilation system, other values can also be set here.
By activating the option "Apply ventilation to all rooms" the room-wise settings are overwritten (table on the next page). However, night ventilation is only taken over for rooms whose windows have a g-value of 0.4 at most when the sun protection is closed, since according to the standard, such a sun protection must also be provided in this case.
Calculation of the thermal insulation
The maximum day and night ventilation can be changed in the table for individual rooms. Since glass porches are not relevant for the verification, they can be removed here.
The main result of the calculation are the excess temperatures (measured in degree hours), which must not be too high.
With the button "View Table / Diagrams" you can switch to the normal view of the time diagrams and annual results.
The proof can be printed via the menu items "File", "Print..." and "Proof of summerl. Thermal insulation".