Fan housing with metal foam and fan having the fan housing

A fan has a fan housing and an impeller mounted in the fan housing. The fan housing has a main case, and a foamed metal plate securely mounted in an air inlet of the main case. Hot air inhaled into the main case is forced to flow through pores in the foamed metal plate. Thus, heat in the hot air is conducted to the foamed metal plate and then to the main case. The heat in the hot air is dissipated to reduce temperature of the hot air in advance. Accordingly, heat dissipation efficiency of the fan is improved. Since the foamed metal plate hinders flow of the hot air, the hot air flowing into the main case is reduced. Therefore, air pressure and flowing speed of the hot air flowing into the main case is reduced, such that noise made by the fan is also reduced.