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What are Evaporative Coolers?

August 25, 2020

An Introduction

Evaporative Coolers, also known as swamp coolers or Open Space Coolers, were developed as an affordable and energy saving method of cooling air. It is typically considered as a cost effective alternative to traditional Air-Conditioning which has high installation and operating costs. Unlike Air Conditioning, Evaporative Coolers produce cool air by way of evaporating water, which is a more natural process. 

To put it simply - during the process of water evaporation, the liquid water needs to absorb a relatively large amount of heat for it to turn into vapor (also known as the Latent Heat of Evaporation). When the resulting water vapor escapes into the atmosphere, this heat is taken along with it. It is this removal of heat that leaves behind air that is cooler than before. Evaporative Coolers take advantage of this cooling phenomenon to produce cool air that can be distributed throughout buildings, open spaces, and finally to people who need to be cooled down. 

How do Evaporative Coolers take advantage of Evaporative Cooling?

Evaporative Coolers use a special high-efficiency cooling media called evaporative cooling pads to facilitate the evaporation of water. In the cooler unit, water is circulated around the walls where the cooling pads are positioned, keeping the cooling media constantly wet. As air is being sucked in through the cooling pads, the water on the cooling media is evaporated thus cooling the air that passed through.

Evaporative Cooler How it works

1. In operation, a water pump circulates water from the water basin to the top of the cooling media keeping it wet all the time.

Evaporative Cooling Pad

2. The running fan causes the outside warm air to be drawn into the cooler passing through the cooling media.

3. As the air passes the wet media, water is made to evaporate. It is this evaporation of water that causes the intake air of the cooler to be cooled down.

What cooling results can Evaporative Coolers achieve?

The evaporative cooling process is a scientific natural phenomenon that relies on nature to take place. Naturally, the cooling results of evaporative cooling will largely depend on two ambient factors, namely the outside relative humidity and outside air temperature. 

Evaporative Coolers deliver better cooling performance in drier conditions where the relative humidity is not too high. This makes sense because the drier the air is outside, the more water from the cooling media can evaporate into the atmosphere. Furthermore, the more water that evaporates into the atmosphere during this process, the cooler the air that is left behind will be. As such, Evaporative Coolers work the best in hotter and drier conditions, and the ASEAN region is a good example of a place that can successfully harness the benefits of evaporative cooling.

In the most ideal conditions, Evaporative Coolers can supply air that is as low as 10°C cooler than the outside temperature. For example, if the outside air temperature is 38°C degrees celcius, the Evaporative Cooler is able to take that air and cool it down to 28°C in the most ideal of atmospheric conditions where the outside air is hot and dry.

To see how well Evaporative Coolers can perform in your area, please contact a sales representative today to receive a free consultation.

Where are Evaporative Coolers typically used?

Evaporative Coolers are appropriate for cooling semi-enclosed buildings to wide-open areas. They are typically seen in industrial applications such as in factories, warehouses, workshops, etc. and can also be found in outdoor commercial spaces such as semi-outdoor shopping areas, office complexes and more. Smaller Evaporative Coolers may also be seen used in residential areas. 

Waterline Cooling Evaporative Coolers are uniquely manufactured to match industrial-grade requirements and are offered in larger airflow capacities to serve the cooling needs of large factories. 

How do Evaporative Coolers compare to Air Conditioning systems?

Evaporative Coolers are not a like-for-like replacement for any HVAC and refrigeration systems. Unlike Evaporative Coolers, Air conditioning uses a combination of coolants and refrigerants to produce chilled air at very low temperatures. Although it may produce very cooling temperatures, it requires a lot of energy throughout the day to do so. For industrial applications, it is far too costly for most facilities to handle the operating cost in chilling an entire factory or warehouse using Air conditioning.

To give a ballpark idea in cost-comparison, to cool an area of the same size, the operating cost of using an evaporative cooling system is an average of 50% less than the operating cost of using an HVAC system. Because of its cost-efficiency, many factory decision makers choose evaporative cooling systems because they can provide a working environment that is comfortable enough at a fraction of the cost of air conditioning. 

Are all Evaporative Coolers made the same?

Certainly not. There are many grades of Evaporative Coolers available in the market. Some may be built with higher quality components, and some may be built with cheaper household grade materials which can seriously reduce the product lifetime. 

What are Evaporative Coolers?

However, you can be assured that Waterline Brand Evaporative Coolers are manufactured to withstand long term use in any industrial environment. We strictly use components that are industrial grade made from reputable manufacturers. To learn more about why you should choose Waterline, read here to learn more about our line of Open Space Coolers.

How is the cool air created by the Evaporative Coolers supplied into the building or areas that need it?

Evaporative Coolers are typically installed outdoors so that the cooling media can be exposed to the outside atmosphere to work effectively. The axial fan located inside the Evaporative Cooler moves the cool air into the building via a series of air ducts. The cool air is finally delivered into the room or space from an air diffuser or air inlet that is mounted on the air ducts. 

What are Evaporative Coolers?

To keep the air cool, it is crucial for the air ducts to have sufficient insulation properties to keep heat from entering the duct system. Read why Waterline Polyurethane Insulated Panels (PIP) are an excellent option for keeping air cool.

If you have any more questions regarding factory cooling solutions, please contact us at

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