How Does an Evaporative Cooler Work? How Is It Different from Air Conditioners?

An evaporative air cooler, also known as the swamp cooler, makes use of the evaporation concept for the cooling purpose.  

I know you guys may be like - ‘Evaporation for cooling? Like how?’  

Hold on while we take you through different concepts on what an evaporation cooler looks like, it’s working and how it’s different from your ACs.  

For a hot, humid climate we will usually prefer an air conditioner, but if the budget doesn’t allow you to buy it you can always rely on an air cooler! There are different ways in which you can cool your surrounding other than the air conditioners. One such equipment is the Evaporative Coolers. 

Well, all machines have their set of advantages and disadvantages. Evaporative coolers are eco-friendly and consume less electricity. This type of cooler makes use of the evaporated water as the cooling agent whereas an air conditioner got the refrigerant that absorbs heat from the air.  

What is an evaporative cooler?

An evaporative cooler is a device that makes use of the concept of evaporation for cooling. This one is different from the conventional air conditioners that make use of the vapor compression technique.  

Here, the main concept is an evaporative cooler absorbs an effective amount of heat in order to carry out the evaporation process. During this process, the indoor evaporative cooler will see a phase transition, that will convert the water to vapor.  

Did you know that evaporative coolers use much less energy compared to that of the refrigeration setup?  

Evaporative coolers are the oldest form of machines, that came in the industry even before the air conditioner system. It is believed that in the 2500 B.C, the frescoes have shown the people fanning the water jars for producing cool air. This simply means the idea of an evaporative cooler is older than you can imagine!  

Now we shall know how this cooler works in real. Explained below. 

How does an evaporative cooler work? 

The evaporative cooler works on the principle of evaporation, and it can be installed both for indoors and outdoors.  


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  1. These coolers first pull in the hot or dry air from the surrounding, and it is then passed via a moistened pad.  
  2. The pads absorb the heat and are efficient enough to cool down the temperature as low as 20°F. So, the thing is – the moisture present in the pads undergoes evaporation giving out cool air.   
  3. Near the output end, there’s one fan attached which circulates this cool air. 

In most of the coolers, there are two filters attached which are dust filter, and the honey-comb filter (moistened pad). You need to make sure that the pads are moistened properly, and the device is rightly set according to the airflow needs at your place.  

Evaporative Coolers vs Air Conditioners 

The evaporative coolers and the air conditioners – both help with cooling your space, however, they do the work differently.  

Working: Air Conditioners, they take in the hot air, cool it down and eject both cool and hot air in and out respectively. Whereas, the best evaporative cooler makes use of the softening pad for absorbing the heat and expels the cool air which is further fan-circulated in the room.  

Temperature Reduction: The score of temperature reduction is low in the evaporative coolers and high on the air conditioner units. Your swamp coolers can reduce the temperature effectively as the water transforms from water to vapor whereas a refrigerant and an energy-induced compressor are used for cooling the air in the latter.  

Energy Consumption: It’s low in the evaporative coolers and moderate-high with the air conditioners.  

Portability: You can keep your outdoor swamp cooler almost anywhere, where you want to. This is however not possible with the conventional air conditioners; they remain fixed on the walls and can’t be moved frequently.  

Outdoor use: Evaporative cooler can go well for both indoor as well as for outdoors. However, your air conditioners are strictly meant for indoor use.  

Room moisture: Your personal air cooler humidifies the room, adds a suitable amount of moisture within a dry air surrounding. On the other hand, an air conditioner dehumidifies the air and is best suitable for high humidity rooms.  

What do you think about evaporative cooler systems? You can share your experience with us or ask your queries regarding cooler usage and maintenance.