Fire Academy Interior Attack Practice Test 2026 - Free Interior Attack Practice Questions and Study Guide

Fog nozzle operation hinges on air entrainment to create a moving mist. When water exits through a fog nozzle, it is broken into tiny droplets and a low-pressure region at the nozzle draws in surrounding air. This entrainment causes the stream to carry a large volume of air along with the water, so the overall effect is a moving mist that displaces heat and smoke. The droplets evaporate, absorbing heat and cooling the space, while the moving air helps push hot gases away from the nozzle and improves visibility. Therefore, the statement that fog streams move large volumes of air along with the water is the best description. The other ideas don’t fit because fog streams actually increase air movement (not keep it constant or reduce it) and they cool rather than increase temperature.