Exploring Evaporative Cooling

Author: Cruz Lia

Evaporation and condensation are integral processes of our lives. The very example of these processes resides in our body – perspiration. When the outer weather gets too hot, our body secretes water – sweat – to cool off the body. This sweat evaporates because of the hot weather, and this evaporation causes a cooling effect. The heat and the humidity in the atmosphere control how quickly you feel cooler; that’s why you feel hotter on a humid day than on a dry day.

This is exactly the principle used in Evaporative Cooling within a datacenter. The process of evaporative cooling has been used very commonly in homes for cooling during summers; the coolers are popularly known as swamp coolers. But it has recently entered the scene of datacenter cooling as an environment-friendly option, mainly because it doesn’t use a refrigerant for cooling.

How does an evaporative cooler work?

A datacenter consists of a lot of equipment which run continuously for a long time. That causes a lot of heat generation, and that’s why there is a need for continuous cooling. Using an air conditioner can shoot up the costs and upset the budget of the organisation. That’s why companies have now moved on to more financially viable cooling options – Evaporative Cooling

In the datacenter, the evaporative cooling system is almost like the other cooling systems. The only difference is that misting system – the moistened pads – replace the cooling coil. The other components of the cooling system such as the fans, return fans, dampers and so on remain the same.

An industrial size evaporative cooler consists of a huge fan which draws in warm air into water-saturated pads. The warm air causes the water in the pads to evaporate and thus cools the air. However, this constant evaporation causes loss of water. That’s why the system consists of a water tank that monitors the moisture level in the pads and keeps the moistened regularly.

However, it is important to understand that evaporative cooling is a technique that is sensitive to the location of the datacenter. It works more effectively in a dry climate than a humid climate.

The other main advantages of an evaporative cooler include:

  • Low installation costs
  • Minimal consumption of electricity
  • Devices are simpler to use and maintain

However, there are quite a lot of issues when it comes to installing evaporative cooling into the datacenter, such as:

  • Scalability: The additional function of constant monitoring of the moisture level makes it a difficult cooler to install.
  • The system depends very heavily on water; not to mention that the temperature of the water should also be monitored for a temperature to achieve perfect cooling.
  • The possibility of leakage of water around electrical and electronic devices. This may be a huge hazard to the operating personnel and the equipment.
  • The climate plays a huge role in the efficiency of the cooling system; it works more efficiently in a dry climate than a humid climate.

Evaporative cooling may be a very environment friendly method of cooling the data center, but it also has a lot of issues surrounding it. That’s why many data centers have not yet considered it as a main source of cooling but a secondary source of cooling. However, there are still many companies who have taken up the cause of evaporative cooling for enhanced operations and increased safety. It’s still a while till evaporative cooling enters the scene with a makeover in the form of functionality and affordability.