Adiabatic coolers, also known as hybrid coolers, are dry coolers that use a combination of sensible cooling and adiabatic cooling of the air to cool water. They have a spray or water trickle system that precools the air before it reaches the coil where the cooling water flows. This precooling of the air is only necessary when the ambient temperature is high, and for the rest of the time, the unit operates as a standard dry cooler.
Adiabatic coolers are typically less energy efficient than open evaporative cooling towers, but they have similar power requirements to evaporative closed-circuit towers. They are capable of cooling water to within 6°C of the prevailing wet-bulb, leading to minimum design cold water temperatures in the UK of 24-26°C.
Even though adiabatic coolers are not currently required to be registered under the Notification of Cooling Towers and Evaporative Condensers Regulations 1992, it is important to assess the risk of legionella in these systems and take appropriate measures. This may include some form of water treatment, equipment monitoring, and risk assessment for legionella.
Advantages of Adiabatic Coolers:
- Compared to dry coolers, adiabatic coolers offer the next most efficient means of cooling water.
- They have a smaller plan area and lower power consumption than dry coolers.
- Adiabatic coolers have lower noise levels compared to dry coolers.
- There is no water loss from the system and water consumption is significantly lower than cooling towers.
- Adiabatic coolers have a closed system, requiring very little water treatment.
- They have lower water temperatures than dry coolers.
Disadvantages of Adiabatic Coolers:
- Adiabatic coolers have higher power consumption compared to cooling towers.
- They have a larger plot size and higher noise levels than cooling towers.
- Adiabatic coolers have higher water temperatures than cooling towers.
- It may be necessary to register them in the same way as cooling towers.
- Adiabatic coolers have approximately half the operating life of cooling towers, leading to a relatively high total cost of ownership compared to cooling towers or other air-cooled systems.
In conclusion, adiabatic coolers are a good option for cooling water but need to be considered carefully to determine whether they are the right choice for your needs. At Vistech Cooling Systems Ltd, we specialize in the design, installation, and maintenance of adiabatic coolers. If you have any questions or would like to discuss your options, please feel free to contact us info@vistechcooling.co.uk & 01403 892622