A gas detection system is provided for identifying a gas. The gas detection system includes a sensing module with a hollow chamber enclosed by a chamber housing. Additionally, the sensing module includes an optical sensing fiber positioned within the hollow chamber. The optical sensing fiber includes a gas sensor including a fiber Bragg grating positioned at a grating location along the optical sensing fiber, and a sensing layer affixed to an exterior surface of the optical sensing fiber at the grating location. After the gas is directed into the hollow chamber, the sensing layer and the gas exchange heat energy, based in part on a heat transfer coefficient of the gas. The exchange of the heat energy induces a shift in a Bragg resonant wavelength of the fiber Bragg grating which exceeds a threshold shift required for detection, where the shift is used to identify the gas.