Evaporative Cooling

– why it is perfect for your business

multiple evaporative cooling units installed in the roof of a factory

Evaporative Cooling

Evaporative coolers use water evaporation to cool the air. This technique has been used in warmer climates for many years. As the effects of global warming are felt in Europe as well, the use of evaporative cooling is becoming more widespread. In ancient times, Arabs used to hang wet clothes to doors and windows to take advantage of air cooling through water evaporation. As the hot air passes to the wetted media (in this case the cloth), the water evaporates and the heat in the air is absorbed, which lowers the air temperature.

Likewise, on days when heat causes discomfort, people often head off to lakes or the seaside in search of relief. Evaporative cooling is, in many ways, simulating the cooler conditions so often found near large expanses of water.

How evaporative cooling works

Evaporative cooling units only use water to cool the air. No chemical refrigerants are involved in the process. Moreover, Evaporative air conditioners use far less electricity compared to refrigerated systems: that all adds up to very responsible environmental and energy saving characteristics.

No matter how hot it gets outside, evaporative coolers use the same amount of power and still deliver 100% fresh, cool air inside. This is in direct contrast to refrigerated systems, which require increasing amounts of power as outside temperatures rise. Evaporative coolers’ cost-saving capabilities actually increase, when the heat is at its highest. At the same time, their performance also increases as temperatures rise – again, in complete contrast to refrigerated systems.

Using little electricity, no compressor and with low running costs, evaporative cooling is the perfect solution for industrial and commercial environments, that often have no cooling system installed at all. Air conditioning is not a viable option, because in warehouses or industrial plants, the capital and running costs would be extremely prohibitive for end-users.

Furthermore, evaporative coolers use 100% fresh outside air. Outside air ventilation is now globally acknowledged as a core component of healthy and comfortable buildings. Evaporative cooling units bring 100% fresh air, never recirculating indoor air. This can be a great solution to improve Indoor Air Quality, as incoming air naturally pushes the stale air outside of the building from doors, windows or extract system.

Evaporative Cooling Benefits Main types of evaporative cooling Climate suitability: Middle East Cooling products

All Benefits

The benefits of evaporative air conditioning are plenty, there’s never been a better time to invest in an evaporative air conditioner which is simple to maintain and operate and offers superior product performance.

With energy prices escalating and summers typically involving heat waves, evaporative air conditioning offers a significant and increasing edge on refrigerated cooling, when it comes to energy efficiency, healthier air flow, performance and easy install and maintenance.

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Cost-effective to run

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The first thing that comes to mind when operating an air conditioner is the running cost. With modern and innovative evaporative cooling such as Breezair by Seeley International you can save you up to 78% on cooling energy bills (1).

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Low water Usage

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Evaporative air conditioners use a small amount of water. A Breezair evaporative air conditioner for example, uses around 40 litres of water per day (2).

By checking water saving features in different evaporative coolers, you will find that Breezair by Seeley International offers a superior water distribution system, water quality monitoring and automatic water drainage which results in minimum water usage for maximum cooling power.

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Easy maintenance

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Regular service by a qualified contractor will ensure an evaporative cooler continues to run at its peak efficiency and maintain low evaporative running costs. Scheduling an evaporative cooling service can be arranged through our network of distributors.

Evaporative cooling units are also very easy to install.

evaporative cooling providing fresh air into the building

Improved indoor air quality with high ventilation

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These times when the quality of the air we breathe is essential, there is nothing worse than being stuck inside breathing stale air for hours on end. Fresh air is a major benefit of evaporative air conditioning, supplying 100% fresh, cool, outside air.

It is important to remember that evaporatively cooled air inside a building is never recirculated, thus improving Indoor Air Quality (IAQ).

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Evaporative air conditioners are enviromentally friendly

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Opting for evaporative air conditioning means that you will not only help the environment, but you will also experience natural, cool, fresh filtered air. Evaporative air conditioners use far less electricity compared to refrigerated systems and therefore minimize the environmental impact.

Evaporative air conditioning systems contain no harmful synthetic refrigerants. Compare this to direct expansion systems which may use potent? greenhouse gases like hydro fluorocarbons or chlorofluorocarbons.

evaporative cooling ideal to cool industrial and commercial spaces

The perfect solution for industrial and commercial buildings

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Evaporative coolers are ideal for big areas, even in semi-open buildings. Sometimes businesses do not have any sort of air conditioning installed as it is too expensive since spaces are too big to be cooled or internal heat-load is too high. With evaporation process you can cool huge areas at a fraction of the costs of A/C, contributing for a healthy building for employees and customers. You can also decide to cool a specific section of the building where operators work or where cooling is much needed: this is called “spot cooling”.

Main types of evaporative cooling

Breezair evaporative cooling installed in automotive industry

Amongst all types of evaporative cooling existing in the market, Seeley International design and manufacture Direct and Hyper-efficient Indirect Evaporative coolers.

Direct evaporative cooling

In direct evaporative coolers, hot outside air is drawn through water-soaked cooling pads. As the air is pushed through these pads, water evaporates and heat in the air is absorbed, which lowers the air temperature. A fan then pushes the cool air throughout the building via a network of ducts. It is called direct evaporative cooling because the air is directly cooled thanks to water evaporation.

Do you want to learn more about direct evaporative cooling? Visit our dedicated page.

Hyper-efficient indirect evaporative cooling

Indirect evaporative air conditioners use a hyper-efficient heat exchanger to produce 100% fresh, cool, outside air, with no added moisture. The fresh cold air produced by indirect evaporative coolers can be similar to that produced by refrigerated systems, with temperatures that approach the ambient dew-point temperature, using up to 80% less energy. The air is indirectly cooled by evaporation inside the core, therefore they are called indirect evaporative coolers.

Are you curious to understand how indirect evaporative cooling work? Visit our dedicated page.

Evaporative cooling and the European climates

Evaporation will take place when humidity is below 100% and the air absorbs water. Any given volume of air can hold a certain amount of water vapour and the degree of absorption will depend on the amount it is already holding. When we say that Relative Humidity (RH) is 30%, we say that air is 30% saturated and it could still hold water for a portion of 70%.

It is the combination of temperature and humidity that creates human comfort, and Evaporative Air Coolers are used so widely around the world because they can create comfortable conditions. Furthermore, comfort is also improved by increasing air velocity in hot conditions and Direct Evaporative Air Coolers create sufficient air movement to also minimise the effects of humidity.

As we can see from the graph, humidity depends on the value of the temperature: during the portion of the day when temperatures are higher, relative humidity is lower. It is during these hot times that cooling is much more needed and it corresponds to the period when evaporative coolers work at their best (when relative humidity is lower). This time also correspond to working hours: this is why many companies decide to adopt evaporative cooling.

Moreover, we said that outside air is pushed inside the building and doors and windows must be left open for air to escape (or extract fans installed).  This way, also air saturated with water (with high humidity) is pushed out, part of the natural flow of healthy outside air that blows inside the building.

Finally, Hyper-efficient indirect evaporative coolers do not add humidity to the air.

We would normally think that evaporative cooling works in arid climates, such as internal locations in Saudi Arabia or Turkey. In fact, evaporative cooling works perfectly in coastal cities like Doha or Dubai. Nevertheless, there are hundreds of units installed in the UAE, that we normally consider very humid. And…they work perfectly! It is all about choosing the right application, unit and properly size the project, both in terms of number of units and extract system.

For all these reasons, evaporative coolers can be perfectly suitable for all the different Middle Eastern climates.

Better for health, better for the environment

Evaporative coolers use water for cooling instead of synthetic chemical refrigerants (CFC’s, HFC’s and HCFC’s). There are no CFC pollutant emissions from evaporative air conditioning and water consumption is moderate. That all adds up to very responsible environmental and energy saving characteristics. Evaporative coolers use far less electricity compared to refrigerated systems therefore, less fossil fuels such as coal and natural gas are consumed in the production of electricity.

For example, direct evaporative coolers by Seeley International absorb 1.2 kW power3 to work: less than a hair drier!

Nowadays, more than ever, indoor air quality is essential for any workplaces.

Drawing fresh air from outdoors, evaporative coolers offer a great health advantage over refrigerated air conditioning, which recirculate the same stale air over and over. Moreover, direct evaporative cooling units provide humidification of the air, relieving dry nose and throat symptoms and asthma. Working in hot temperatures often causes heat stress and, in some cases, fainting and in rare (but not negligible) cases heat stroke. Improving temperatures in companies is therefore necessary and mandatory.

Are you curious to see how ventilation is important to improve indoor air quality? Have a look at our article “Building ventilation and Covid19 containment guidances”


  1. Seeley International’s running costs comparison is a calculation based on assumptions including Building dimensions 900m2 floor area x 6m high; Cooling time 12rs/day, 12 summer months/year; Indoor temperature 24°C; Internal building heat load 13.5kW; Fresh air 4500 l/sec; Refrigerated A/C COP 3; External ambient conditions based on 2018 Riyadh (Saudi Arabia) weather data; Power cost 0.05USD/kWh; Water cost 1USD/kl; Electricity Generation CO2 equivalent 700gCO2eq/kWh. The comparison should be used as a general guide only.
  2. For all power consumption, see Breezair technical sheets https://www.seeleyinternational.com/me/commercial/service/product-brochures//