nv-calc EN

Ventosystem nv-calc EN
nv-calc - computation program

nv-calc is meant for designers to calculate natural ventilation. The program is mainly suitable for industrial facilities in which, as a result of a manufacturing process, a significant thermal load is created. The thermal current generated by a heat source in industrial facilities is a sufficient “driving force” behind ventilation which gusts of wind are not able to disturb.

Input data for the program consists of thermal load, parameters of inlet and outlet vents as well as mechanical ventilation devices installed in them. The program calculates the maximum temperature under the roof, the quantity and speed of air flowing through each vent as well as pressure leveling in the building. The program allows for taking into account mechanical ventilation and wind effects.

nv-calc operates in three languages: Polish, English, and German. It is able to produce a report with all numerical data and a diagrammatic drawing of the building in each of those three languages. The program can be run, for instance, in the Polish language and then a report in another language can be printed additionally.

If you want to get free access to professional version of the nv-calc program click here

nv-calc account will be activated no later than the second working day.


  • This license agreement applies only to the SOFTWARE of the professional-version of the nv-calc program.
  • The firm VENTOSYSTEM Bohdan Kontrymowicz is the Owner of the program and the Company maintains the legal copyright to this program.
  • This program is dedicated to designers for calculating the natural ventilation of workshops, specially industrial buildings with high thermal load. Any final reports produced with the assistance of this software may be included into the User’s projects, but in its original form only. No changes, especially those that do not credit the origin of the software’s ownership are allowed.
  • This license empowers the User for legal use of the program after registration and activation of the account by the Owner. This program is free of charge.
  • The login data to nv-calc program in the professional version cannot be made available to any third party (none registered) without Owners knowledge and agreement.
  • Legal liability restrictions apply. The contents of these restrictions are displayed on the program's homepage and also on the report of the calculation printout.
  • VENTOSYSTEM reserves the right to contact the User of the program in order to offer any additional or new information and to solicit the User’s comments and opinions, in order to improve the next upgraded versions of the program.

Formulas in this program are created to determine equilibrium between all thermal gains produced by industrial processes within a building as well as air flow exhausted by the ventilation system. Based on this principle, the program is not intended to calculate air exhaust used to prevent thermodynamic disasters such as fires or an explosion blast in the case of accidental discharge of flammable gases. This program requires the user to possess and apply engineering knowledge and to understand physical phenomena occurring in the natural ventilation of buildings. The results of the program’s calculations will always correspond to the adopted criteria and the input data which have been entered, for which only the user is responsible.

We cannot be held responsible the for the design assumptions and data / Legal liability disclaimer:

All data, information and theoretical assumptions for calculations used in our program have been carefully analyzed and verified by Ventosystem. However, the possibility of the occurrence of errors cannot be ruled out completely. We cannot be held responsible for the correctness, completeness and the ongoing pertinence of calculations results obtained on the basis of input data which were not authorized or verified by Ventosystem.

In particular, Ventosystem is not responsible for any damage and consequences arising as a result of indirect or direct application of calculations which have not been authorized by us. Ventosystem is not responsible for uncritical use of the results for applications which have not yet been tested. Please send remarks and suggestions for corrections to biuro@ventosystem.pl