A gas accumulation detection and ventilation system for a gas turbine enclosure includes a pipe array positioned adjacent a floor of the gas turbine enclosure and a ventilation assembly including a fan, an air flow inlet and an air flow outlet. The pipe array includes at least one pipe having at least one opening therein. The fan of the ventilation assembly directs an air flow sweep through the air flow inlet along the floor of the gas turbine enclosure. A hazardous gas sensor panel in communication with the pipe array and the ventilation assembly detects an accumulation level of turbine fuel gas in the gas turbine enclosure based on input from the pipe array and activates the ventilation assembly according to the detected accumulation level.