Cooling tower systems are typically broken into two groups: dry cooling towers and wet cooling towers. However, another important distinction is between open and closed loop cooling systems; although open systems tend to be a little more common, there are still some important benefits of closed cooling tower systems:
- The initial cost of a closed cooling system is usually higher than what you’d pay for an open cooling system, primarily because the system requires more energy to operate; because the excess heat doesn’t come into direct contact with cool water, it takes more energy to transfer the extra heat out of the system. However, the cost generally decreases over time, compared to open cooling towers, and closed systems have a fairly long lifetime.
- Closed cooling tower systems are often considered more eco-friendly because the water doesn’t come into contact with the hot equipment and therefore doesn’t absorb extra dissolved gases and particles that can’t always be filtered out. With an open system, a complex filtering system is required to filter out the cooling agent, but it isn’t always possible to filter out everything.
- Closed circuit cooling towers can also stand higher temperatures, compared to the average open circuit tower, by using dry coils to transport the hot and cool fluids. These coils need to be replaced regularly and can be a little pricey, but they are relatively easy to clean in between replacements and very little additional maintenance is required.
- Because the cooling agent is isolated from the hot equipment, closed cooling tower systems can use non-water fluids to absorb the extra heat. It’s often easier to clean these fluids, there isn’t any concern about replacing enough evaporated fluid so the system will continue to work, and the system doesn’t have to be shut down completely when the fluid is being cleaned out.
If you’ve ever had to use a cooling tower system before, did you use an open or closed system? What made you choose that particular system? We’d love to hear any comments or questions you may have!