How Effective are Evaporative Coolers

The evaporative cooler, otherwise known as a wet air cooler or a swamp cooler, or a desert cooler is a piece of equipment which is primarily used to cool air through water evaporation. Most often a lot of people replace our normal air conditioner with an evaporative cooler because they feel that the evaporative cooler is actually more effective in doing the right job.

But are they really that effective? Or is it just a scheme? One of the significant differences between the evaporating cooler and the conventional air conditioning system is the use of a vapor-compression or absorption refrigeration cycle. 

Evaporative coolers and air conditioners are quite similar in a lot of ways, which is why both of them are usually interchanged by a lot of people today. But one of the significant differences is that the evaporative cooler does not have an exhaust hose or a condenser box outside.

Also, they are different from a refrigerator in that they do not produce refrigerant air, but provide a relaxed atmosphere. But there is a big question that always needs to be asked, how effective are these evaporative coolers? Do they really cool the environment where they are installed?

Before we get into the effectiveness of evaporative coolers, let’s first look at how they work, and the principles behind it. Evaporative coolers can actually be used for cooling in a different range of areas; some evaporative coolers are ideally constructed for a 120ft2, while others are built for a larger area of 2000ft2.

Evaporative coolers are cooling equipment that is an efficient, economical and environmentally friendly way of cooling. Although they are quite useful and practical in their use, there are also some restrictions as to the use of the evaporative cooler.

For instance, they are not to be used in a closed and unventilated environment; this is because they rely on the flow of fresh air to work more efficiently. Basically, in an unventilated area, the use of an evaporative cooler may be doing more harm than good. This is because evaporative coolers would directly pump humidity into the atmosphere. As a result, they make closed spaces very damp, which could be damaging to electrical systems or other things in the area.

So, in essence, evaporative coolers are meant for environments that have adequate natural ventilation, and not for closed spaces. This is one of the limitations of an evaporative cooler. You can find evaporative coolers in a lot of places today, but not a lot of users are familiar with the actual working principles of the machine they purchased.

When you have a basic knowledge of how the evaporative cooler works, then you would be able to avoid some specific issues or problems that could occur and thereby improve the cooling ability of the system.

How Evaporative Coolers Work

Evaporative cooling isn’t actually a new technology, as it can be dated as far back as the ancient Egyptians and Persians thousands of years ago. In an evaporative cooler, energy in the form of heat is needed to evaporate the water.

For every gallon of water that is evaporated, 8700 BTUs (British thermal unit) of heat are required. This heat is acquired from bodies that the water comes in contact with, like the building, your body, a tree, or even the air itself. As soon as the evaporated water comes in contact with the heat source, it evaporates and reduces temperatures around it.

It is also essential to understand that the temperature of the water is not what causes the cooling. Furthermore, it does not cause any real effect on the cooling produced by the evaporation process.

For example, if you pour a gallon of water at a temperature of 50oF on a body with a temperature 90oF. It would produce 9000 BTUs of cooling, also if you are to pour a 90oF of water this time around on a body, it would generate 8700 BTUs of energy, and that is about only 3% difference.

This is basically the working principle of evaporative coolers; imagine if you are being sprayed with water at any of the above temperatures, on a hot day, the evaporation of the water from your skin is what would cause the cooling effect that we need.

Also, in the building of an evaporative cooler, some certain parts like the filter pads are located at the back or side or even at both sides of the machine, and the surrounding warm air is sucked out of the environment through these pads. 

The pads are usually damp either because of the water that is being pumped from the internal reservoir around and through the pads, or from an external water source. When the warm air that is outside begins to move through the wet pad, the water starts to evaporate, and as a result, it removes the heat from the atmosphere. As soon as the air leaves the machine, it is in a colder state than when it enters the device.

It is essential that the machine draws in as much of the warm air as it can. That’s because as the warm air passes through the device, it cools the environment.

There are still some practical notes that can ensure you get the best out of your evaporative cooler. It is important to note that the lower the relative humidity is, the better the performance of the cooler, and typically a relative humidity of 70% or lower is quite good.

Also, cold or iced water does not really contribute to the cooling efficiency of evaporative coolers. And lastly, it is important to note that evaporative coolers must only be used in areas with proper natural ventilation or adequate mechanical air extraction units.

Evaporative Cooling Versus Air Conditioning

One way to entirely understand the difference between each of these cooling systems is to look into the features of both systems. When we see how they both work, then we would be able to know how they differ from each other. What they have in common is that they are both used as a cooling system in a lot of places today.

Which one is more efficient depends on how they are used. How we use a cooling system clearly tells how effective it would be. So it all depends on you and what is right for you, because they both do not work on the same principles, but they are both used for cooling.

Evaporative cooling has been one of the oldest methods that have been used for controlling the climate. And they are still present one of the most popular systems that are used for reducing the heat inside the home. A lot of people use this at home because they are powered efficiently, and it saves you some cash for that bill. Now some of the differences that exist between both cooling systems are as follows;

  • The evaporative coolers are cheaper to run as they do not really need as much power to function.
  • They are excellent on energy and perfect for dry and hot climates.
  • They produce fresh air that is clean to breathe in.
  • They are quite easy to install, and they do not really require so much maintenance, and one of the best parts about the evaporative cooler is that they do not emit so much CO2.
  • Evaporative coolers are one of the best substitutes for air conditioning units, but sometimes they are not always the best solution, it all depends on the climate you live in. An evaporative cooler reduces the heat in an environment utilizing water evaporation, which adds moisture back into the air.
  • The only drawback about the evaporative cooler is that you would have to keep your windows open to allow the flow of fresh air while they are being used, as this prevents the buildup of moisture in the environment.
  • Due to how an evaporative cooler works, it has been recommended that they are used only during the dry season, and in hot climates, like in the Southwestern part of the United States, and not in all humid areas like in the Eastern United States.
  • When you compare this with the air conditioner, you will find out that they do work practically in every type of environment, and they are also handy in an enclosed environment.
  • Air conditioners can also be a substitute for both homes and commercial spaces. The air conditioners are also used to remove moisture from the air, which in turn makes the environment less humid, and this allows the background to get cooled on time.
  • Another thing about the evaporative coolers is that these machines are not very noisy because they do not make use of a refrigerant and a compressor. But they simply just suck up dried air from the environment and expel wet air that actually makes the atmosphere of the climate humid and as a result of the water in the air, as the water touches any material, the evaporative effect of the water on the body is what actually brings about the cooling results that are desired.
  • When compared with an air conditioner, the air conditioner makes a lot of noise due to the refrigerants and the compressor that are used by the air conditioner to bring about the cooling effects that we require.
  • The air conditioner actually sucks up air from the environment and passes it to the compressor where it actually mixes with the refrigerant to produce a more cooling air that is being expelled to the atmosphere and the coolant extracted in other for it to complete the same cycle again.

Air Quality of an Evaporative Cooler

Let us assume that we are comparing the air quality of an evaporative cooler with an air conditioner, and we do not take into consideration the location, then we can say that the evaporative coolers are better because the air quality of the evaporative coolers is better.

When using an evaporative cooler, doors and windows do not need to be closed while they are running , and because of this, the air in the room is not re-circulated, meaning that it is not only the air that is in the place that is maintained, but fresher air from outside can actually flow into the space. This, in turn, just means the quality of air in an evaporative cooler is fresher.

Also, it is important to note that evaporative coolers would not dry out the air, in the sense that they do not make the air in the atmosphere less humid, but slightly more humid and as a result the air is cold. The evaporative cooler puts moisture into the air, and this just simply means that you would not have dehydrated skin and eyes as a result of being in a room that is not humid. For example, when you use a cooling system like an air conditioner, you would often notice that your skin and eyes would get dry a lot, as a result of the removal of moisture from the air.

Moreover, if you are the kind of person that suffers from a lot of allergies, then you would definitely need an evaporative cooler. Because when you compare the two of them, you will come to understand that the air conditioner produces a more stuffy air that is not so fresh and as a result, can easily trigger allergies. But when you are using an evaporative cooler, you would realize that it may actually promote fewer allergy symptoms. So, therefore, people who have asthma can actually use an evaporative cooler because they help them feel better.

Considering an Eco-Friendly Cooling System

If you are considering an eco-friendly cooling system, then you should think of an evaporative cooler, as it is one of the best eco-friendly cooling systems you can get in the market. Moreover, they work without emitting as much CO2 to the atmosphere like other cooling systems, e.g., air conditioner.

When you choose an evaporative cooling system for cooling your apartment, you are reducing the carbon footprint. This is another way of cutting one of the major causes of global warming. Apart from the carbon footprint that the evaporative cooler reduces, they also operate more quietly than most of the other cooling systems, so you are also helping the ecosystem by reducing noise pollution.

Also, they do not really require a lot of energy to power them, so they are very light to operate, and because they are light to work you do not need to a potent source of electricity like gasoline-powered generators to power them. They could easily be powered by solar panels, and this also helps in reducing the carbon load in the atmosphere, thereby improving the ecosystem to thieve more and also help to stop the fast-spreading global warming.

Things to Consider

Evaporative coolers are quite the useful, economical, and environmentally friendly method of cooling, so it is essential to know that some conditions are more favorable for the evaporative coolers than others.

  • he climate where the evaporative cooler would be more useful is one thing to consider because not all environments are so compatible with the evaporative cooler.
  • Do not get the evaporative cooler because it is cost-effective and straightforward, but also check your climate to know if the evaporative cooler would be useful. As another name of the evaporative cooler suggests "swamp cooler" they are generally more effective in cold, muggy, swampy areas, but would be ineffective in warm, humid areas. This is because the air is so heavily saturated with moisture, and as a result, instead of the evaporative cooler to cool the atmosphere as the mist evaporates.
  • You also need to consider the size of an evaporative cooler that will be most effective for your apartment space. Because in order to get the best result from the evaporative cooler, you need to make sure that you have the correct size of an evaporative cooler for your apartment space. If, for example, you have a large apartment space, and you buy a small evaporative cooler, the evaporative cooler would have to work extra hard in order to keep the apartment atmosphere cool. And the CFM (cubic feet per minute) is actually the amount of fresh air that is cycled through the environment per minute.
  • Lastly, in order to get the most effectiveness out of the evaporative cooler, you also need to consider the different types of evaporative coolers. Basically, there are two major types of evaporative coolers, and they include the residential evaporative cooler and the industrial evaporative cooler. These two types of evaporative coolers have been designed to cool both small and large spaces. Most of the evaporative coolers usually come with casters which indirectly makes moving the evaporative cooler from one area to another space easier. 


Having said all that there is to be said, the effectiveness of the evaporative cooler dramatically depends on the way and manner in which you use it and also your climate can also significantly affect the efficiency of the evaporative cooler.

Basically, a lot of people do not really know just how beneficial the evaporative coolers are, but I hope that with this guide, you are able to understand why you need to get an evaporative cooler for your apartment.