The app "Calculation Hole" is a tool extremely easy and fast to use to calculate the correct size of the exhaust vent. A useful tool maintainers of boilers and gas equipment installers, verify the correct sizing of the ventilation hole it is one ofobligations in terms of security set with the UNI 7129 / 08-2.With this application you can calculate the diameter of the ventilation in rooms where appliances with burners are installed that draw from local combustion air where they are installed (gas appliances of type A or B or cooking appliances). The "Calculation Forum" will guide you step with a few simple questions related to establishment, the type of equipment and its power. According to the data provided the calculation function will also display alerts in the event of non-compliance. E can also save the surveys conducted for future reference.Disclaimer:The application is a tool that helps the installer and maintainer in the simple calculation of the diameter of the aeration and ventilation openings UNI 7129/08 but does not replace it substitute their own choices made by the professional who performs the procedures on field.The legislation indicates the minimum values in certain specific circumstances, the professional who performs the verification at the premises must take into account other factors that could lead to a larger cross-section or non-suitability of the premises.To the extent permitted by applicable law, in no event shall the manufacturer or licensors shall be liable to the end user in the case of damage arising from the use of the software.