Last edited: 7th September 2023
Evaporative Coolers are often referred to as:
- Air Cooler
- Swamp Cooler
- Desert Cooler
- Wet Air Cooler
Or a combination of the words used above. These devices are a cheaper alternative option for keeping you cool in summer.
They come in a variety of sizes, colours and designs, from numerous manufacturers and the market place is filled with options, from small desk size personal coolers all the way up to huge factory size systems with the ability to cool a whole building and its occupants.
The main thing to understand is that an evaporative cooler is NOT an air conditioning unit/system and will not achieve the same results as any type of air conditioning product. That said, they still make a great cooling option for a fraction of the cost of an air conditioning product.
How does an evaporative cooler work?
Evaporative coolers work by using the process of evaporation to lower the ambient temperature within the area it is being used, aiding to maintain a cooler environment. In the case of these units, the evaporation cycle is used to convert water into water vapour, which is then dispersed with the air via the use of a fan.
In order to get the best results, the colder the water in the tank (most units allow for you to add ice or cooler blocks to the water, the cooler you can get the air within the room; it’s as simple as that!
The units main components are:
- A fan
- A water tank
- A water pump
- A cooling pad
Water is poured into the water tank (to a maximum fill level shown on the tank) which is then pumped around the system via the water pump.
The water is usually pumped to the top of the unit and then released over the top of the cooling pad.
The cooling pad gets saturated with water and holds some in place for the fan to draw air through the cooling pad.
The air that is pulled through the cooling pad, absorbs the water molecules, turning dry hot air into cooler, damp air and is then pushed out from the unit via the fan to be circulated within the room.
Because the air coming from the unit is damp, these units are best used in an area where there is good air flow with open windows and/or doors so as not to turn the environment into an area of high humidity (hence people sometimes referring to these units as swamp coolers).
Is an evaporative cooler better than an air conditioner?
The answer to this all depends on where and how you wish to use the product. If you are trying to cool a bedroom with closed windows, then no, you would be far better off with an air conditioner, as these operate best in a sealed environment. However, if you are attempting to cool a living room with doors and windows open to the outside, then this would be a better option as you get the fresh air from outside, being pulled through the unit and the humidity will escape back outside.
Another great thing about these products when compared to an air conditioner is that they can happily be used outside! If you try and use an air conditioner outside, the cooling effect will only be felt very close to the unit and the energy consumption will be high, as the unit is trying to cool the whole outside world. However, an evap cooler (as long as you select the one with the right size fan and motor) will work fine outside and you can direct the air to your location to feel the effects of the cooling breeze.
Efficiency
Because evaporative air coolers do not have to run a compressor, the energy usage is extremely low (when compared to an air conditioner) which in turn gives great energy efficiency.
If you compare an evap cooler suitable for a room size up to 20m² against a portable air conditioner suitable for the same size area, you will notice a huge difference between the input power.
For this comparison, we have compared a Predator P20 vs a Lux Air KYR-25, the input power is shown for both below:
Predator P20 = 60W
Lux Air KYR-25 = 1kW (1000W)
As you can see, it will cost a far greater amount to run an air conditioner than it would an evaporative cooler (but remember, the resulting temperature will also be very different).
Functionality
Every manufacturer will have their own list of added features for these devices.
If you are looking for a cheap and cheerful personal desk cooler, you will likely get nothing but a basic unit in a compact casing. Whereas if you are looking for a unit to use in your residence, you could opt for a model with added features such as UV lights to attract insects, Sleep mode to give a quieter fan speed for peace at night, Turbo mode to give a boost to the fan speed and Timer functions (so the unit can turn itself off after a desired length of time). See product descriptions for more specific individual product details
Water Tank
Evaporative coolers, as we know, use water to cool the temperature of the air.
This is useful information to know as it can also influence the choice of unit you chose to purchase. The larger the water tank, the less often it will require filling.
If the water tank runs dry, the unit will still operate but it will then operate with no greater cooling effect than a conventional fan.
Some products are equipped with the capability to be connected to a permanent water supply, so that the unit cannot run out of water (this is often only on the larger model though).
Portability
The smaller desk sized units are often very light and only weigh just a few kilograms. As the unit doesn’t contain too many parts, the weight of the devices are usually lower than air conditioners and as the items get larger, they often have wheels or castors attached t the bottom for ease of movement.
They thing to remember is the larger the water tank, the heavier the unit can (potentially) be. One litre of water weighs approximately one kilogram, so if you have a unit with a water tank capacity of 15 litres, when you fill it, you will be adding approximately 15 kg’s extra weight to the overall coolers weight.