The cooling of hot equipment is very vital in almost all industries. The wet/dry cooling towers are widely used as the primary cooling systems in most industries. Alternatively, there are other sources of airflows, which can be used as the cooling flow in auxiliary cooling systems. Most industries use many large fans in their lines to complete their required processes. The present work provides a feasibility study to evaluate the capacity of an available large fan in the process line of a pelletizing plant as an auxiliary cooling system to cool down the hot water returning from the hot equipment. The suggested gas-liquid heat exchangers are the 5-meter in height radiators. They are located in the fan's air intake. The preliminary design is modeled and simulated numerically to evaluate its cooling efficiency. Then, according to the design point of the process fan and the functional characteristics of the radiators, the system is redesigned until achieving an optimum cooling system design. Furthermore, the effect of this auxiliary cooling system is investigated at different ambient temperatures. Currently, the pelletizing plant uses wet cooling towers to cool its furnace, which needs about 7.9 MW of heat release. The design point of ambient temperature for this wet cooling tower is 18 °C. The present study suggests an auxiliary design with a cooling capacity of 4.9 MW up to an ambient temperature of 18 °C. The designed auxiliary cooling system also reduces the water consumption of plants significantly.