Centrifugal fan plays an important role in heating application. Fans, due to their reliable and simple structure, are adopted widely in various industrial application, such as in HVAC, automobiles, ships, computer and electronic appliance units. A fan is typically a mechanical device causes a movement of air, vapour and gases in given different system. This study presents the study of important parameters of fan for best possible results. The effect of variation in these parameters is been discussed. Under this project, testing of an impeller fan is done. This fan is used for heating purpose in the industry. Test rig has been made for the impeller fan. Testing has been carried out to evaluate the performance of an impeller fan by considering the key parameters such as flow, pressure, velocity, noise, power consumption, air temperature in various cases like considering resistance to flow with baffles and without baffles. And this results in variation in circulations per hour. From this, best possible results have been found out. After getting the best possible performance from the testing, criteria for sizing has been done as per requirement.