This master thesis deals with flow velocity analysis at the inlet of a radial fan, which is mounted inside a household refrigerator. The refrigerator is operating on a principle of no-frost technology, which prevents formation of ice on the evaporator; radial fan is the key element when it comes to cold air transportation inside of the refrigerator. The theoretical background provides information on cooling cycles, principles of turbomachinery and methods on measuring both air velocity and pressure. Furthermore, we have detailed the design and working principle of the experimental system, the module with a radial fan and an evaporator was fitted on. We were changing the size of the air gap between the inlet and the impeller and measured flow velocity and pressure at the suction side of the fan. We analyzed the results, calculated volume flows and on the basis of measured pressures, we determined the operating point of the fan on the fan characteristic. Graphically we showed the velocity field at the inlet of the radial fan.