Anti-icing systems (AIS) are used in aviation and in ground gas turbines operating in humid climates where relative humidity is above 80% with mist and the temperature of the intake air drops to 5°C and below. Ice formation can disrupt the compressor work by causing vibrations, inlet flow blockage or even a surge in some cases. An anti-icing system is activated in such cases to heat the inlet air before it reaches the compressor. The objective of this work is to design and study an anti-icing system (AIS) for different ambient air parameters and different gas turbine modes of operation. A particular climatic situation (Saint-Petersburg, Russia) is considered as the basis for assessing the suitability of different anti-icing systems and to choose the best configuration out of different possible arrangements. The present work is divided in three major tasks. The first task involves the choice of the anti-icing system arrangement. The second task is to design the heating air supply system by determining the geometric sizes of bypass pipeline with fully open damper to ensure conduction of required air flow at the anti-icing system design condition. In the final task, the entire process is integrated and automated to calculate multiple iterations for different gas turbine operating regimes to assess the reliability of the designed anti-icing system at all operating conditions of the gas turbine. Such assessment is critical as it helps to identify the operating conditions at which the designed anti-icing system would not be able to heat the intake air to a certain temperature above the dew point temperature.