A self-contained compressed air foam system suitable for retro-fitting into small fire appliances. System comprises of a compressor and drive motor, foam proportioning system and mixing manifold all contained within a rigid frame. Water is supplied from the vehicle or portable pump and foam concentrate from vehicle foam tank. System operates at pressure range 4 to 10 bar. The FoamLogix proportioning unit provides accurate and reliable injection of foam into the water stream between 0.1% and 9.9%, and also displays real time data on foam and water consumption. Safety interlocks ensure absolute security of operation for interior fire fighting. An economical and efficient system for gaining the benefit of compressed air foam fire fighting.