Thermal-energetic Building Simulation


  incl.  Cooling Load according to VDI 2078 and Summer Heat Protection according to DIN 4108-2

Version 7.31      Copyright 1978-2022 by Rouvel, Munich FRG








    with   GEBSIMU

         the  future  ahead







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  Cooling load                     

      according to VDI 2078



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  Curriculum Vitae            

    of Lothar Rouvel                        




     by Lothar Rouvel                      










 Last change:

03. February 2022



Lothar Rouvel




O v e r v i e w


A technically flawless, cost-effective and timely planning of buildings and building services requires the use of modern planning tools and methods. This also applies to aids for daily planning work such. e.g. calculation programs, simulation programs and mathematical tools for system analysis and verification of planning decisions. This makes it possible to ensure a high degree of planning security, even with unusual new concepts.


The program system  Thermal-energetic Buildung Simulation GEBSIMU "  was developed in the early 1970s by Prof. Dr.-Ing. habil. Lothar Rouvel,  Technical University of Munich, and has been continuously updated and developed ever since.

Until the early 1980s, the program was only available for mainframe computers. Meanwhile, the program runs on PC under Windows and has a very comfortable and time-saving input with a comprehensive plausibility check.

The program GEBSIMU has participated in the first international comparison of dynamic simulation programs as part of the International Energy Agency (IEA) ECBCS Annex 1 "Establishment of Methologies for Load/Energy Determination of Buildings"  in 1977-80 and has been successfully validated.

In the course of processing the VDI 6020 it has been tested and calculates the test examples without deviations; i.e. all requirements of VDI 6020 are fulfilled 100%.

In addition, GEBSIMU is one of the very few programs with which a system simulation for all types of plants can be carried out correctly.

An essential part of the program is the coupling between building simulation and plant simulation in both directions. If boundary conditions are changed in the plant simulation that influence the results of the building simulation, the building simulation is automatically called up and the results are set correctly.

. For most programs, this feedback does not occur. Only programs with this feedback are able to calculate the effect of low system performance on room temperatures. A program-controlled change of a variable sun protection to avoid artificial lighting is only possible with feedback. The same applies to an automatic calculation of the system running time due to the start-up conditions with an advance of the heat-up time or pre-cooling time.

GEBSIMU  is also able to calculate natural ventilation, transparent thermal insulation, component cooling, cooling ceilings, variable volume flows, lighting requirements, etc.

In addition to the room air temperature, the perceived (operative) temperature is also displayed.. Also a regulation of the room temperature after the operative temperature is provided.

GEBSIMU has a convenient graphical and alphanumeric output, as well as interfaces to MS Excel and a variety of graphics formats.

GEBSIMU   uses the n-Capacity-Model (reference method for validation according to VDI 6020) from Rouvel to determine the thermal peformance for a room (heating and cooling load) and room temperatures.

Alternatively,the 2-Capacity-Model  (Room model according to VDI 6007-1) by Rouvel and Zimmermann is available in GEBSIMU.


GEBSIMU  calculates both the heating and cooling requirements and the power requirements for lighting and air transport as well as the room conditions during a "test reference year" as well as the performance values ​​during winter and summer extreme outside climate conditions.

In GEBSIMU i is the calculation of the cooling load and room temperature according to VDI 2078 from Juni 2015 included.

The summer design is calculated using the Cooling Design Period (CDP) and the Cooling Design Day (CDD) according to VDI 2078 .

GEBSIMU  also carries out the individual summer heat protection according to DIN 4108-2.

With GEBSIMU  the differentiated determination of the useful energy demand in accordance with DIN V 18599 can be made to prove the energy efficiency of the building.

With GEBSIMU  all  locations around the world can be considered

GEBSIMU   is validated according to:

VDI 6020

VDI 6007-1

VDI 2078


DIN EN ISO 52016-1

Declaration of Conformity to VDI 6020

Declaration of Conformity tor VDI 2078






You can download an overview of the program system

" Thermal-energetic Building Simulation  GEBSIMU "

GEBSIMU __Introduction








 VDI cooling load calculation

according to VDI 2078 (June 2015) :

 alrready included  since   2005


Summer heat protection

according to DIN 4108-2 (February 2013) :

 alrready included  since   2000


Calculation with the 2-K-Model

according to VDI 6007-1 (June 2015 ) :

 alrready included  since   2003


Calculation with the window model

naccording to VDI 6007-2 (March 2012 ) :

 alrready included  since   2005


Calculation with the model for

the solar radiation

according to VDI 6007-3 (June 2015) :

 alrready included  since   2003


Calculation with the n-K-Model

(Reference model of VDI 6020) :

 alrready included  since   1978


Validation according to  VDI  6007-1,

VDI 2078, VDI 6020,


DIN EN 15265 and DIN EN ISO 13792:

 alrready included  since   2010


The n-Capacity-Model of GEBSIMU

is reference method for the validation of

"thermal-energetic calculation methods

for buildings and building installations simulation"

(according to VDI 6020) :

 alrready included  since   2010

Additional features :


Design calculation for

Cooling Design Period and

Heating Design Period :

 alrready included  since   1978


Locations around the world,

also southern hemisphere :

 alrready included  since   2008


Consideration of the city effect

on the outdoor climate :

 alrready included  since   2009


System feedback on

room temperature and on

power demand :

 alrready included  since   1978


Consideration of a permissible

fluctuation range for the

room temperature :

 alrready included  since   1999


Alternative regulation according to

the operative room temperature :

 alrready included  since   2008


Surface embated cooling amd heating systems

incl. thermal building component activation :

 alrready included  since   2008


Extended 2-Capacity-Model with

 differentiated consideration of

 surface embated cooling amd heating systems

incl. thermal building component activation :

 alrready included  since   2015


Differentiated consideration

of windw ventilation :

 alrready included  since   2000



lighting switching :

 alrready included  since   1978


Determination of the daylightquotient

based on DIN V 18599-4

without additional data entry :

 alrready included  since   2011



HVAC system simulation:

alrready included  since   1978