Figure 7.25 shows an air-cooled heat exchanger.
The hydraulic fluid to be cooled is pumped through the tubes that are finned. As the fluid flows through the tubes, air is blown over them. This takes away the heat from the tubes. A fan driven by an electric motor is incorporated in the heat exchanger to provide air for cooling. The heat exchanger shown above, uses tubes which contain special devices called turbulators whose function is to mix the warmer and cooler oils for better heat transfer.
Advantages associated with air-cooled heat exchangers are:
1. Substantial cost reduction because of the use of air for cooling purposes, as compared with water
2. Lower installed costs
3. Possibility of the dissipated heat being reclaimed.
Disadvantages of air-cooled heat exchangers are:
1. Relatively larger in size
2. High noise levels
3. Higher installation costs.