The harsh environment of the arctic requires specialized safety solutions. One main safety issue in the arctic is the need for more enclosed modules. Enclosed modules are used for two reasons; to prevent: process equipment from ice and snow exposure; the cold climate imposing an unduly harsh working environment for operators. The enclosed mechanically ventilated process modules are different from the open naturally ventilated process modules that are normally used in offshore facilities. The explosion safety performance of the non-standard mechanically ventilated process modules has therefore been studied in detail through an extensive program of CFD simulations. It is seen that mechanically ventilated modules have explosion risk drivers that are distinctly different from risk drivers in naturally ventilated modules. Several unique factors are seen to have significant impact on the explosion risk levels of confined process modules; the module size; the HVAC philosophy; the ignition source isolation efficiency; and the use of pressure relief panels. This paper discusses one of the main explosion safety drivers for mechanically ventilated modules; the HVAC system. The presented conclusions are of great importance for future development in the arctic climatic environment.