Air Cooler vs Air Conditioner: Which One is Better?


Air coolers and air conditioners are products that we can use to cool our house and get comfortable. But, if you have to pick between an air cooler and an air conditioner, which one is better?

Air coolers work best when the indoor humidity is around RH 20% and below. So, if you are living in places where the humidity level is around RH 70% and above, use air conditioners instead of air coolers.

Many people mistakenly thought that air coolers can cool just like air conditioners but, it's not true. Understanding the working principle behind air coolers and air conditioners can help you decide which one is more suitable for you.

How Air Coolers Work?

Air coolers are also known as evaporative coolers. They need us to refill water from time to time. Air coolers generally don't cool very well. However, they are pretty useful in dry climate countries.

Air coolers work by the principle of evaporative cooling. They use water evaporation to absorb the heat energy from the air thereby cooling the room. Thus, their water gets lesser over time.

A typical air cooler
Air cooler working diagram

Air coolers have a pump to push the water in their basin up and spray the water onto their infill. By spraying the water onto the infill, they increase the contact surface of the water which helps the water to evaporate faster.

You can think of air coolers work like when we hang our clothes. When we hang our clothes, we spread out the clothes to allow them to dry faster. If our clothes are squashed together, they don't dry out that easily right?

So, it's the same principle applies here.

Air coolers spread out the water so that the water can absorb more heat from the air and evaporate faster. In addition, air coolers use a fan to make the air move so that the water can contact with even more air and thus, absorbing even more heat.

Hence, air coolers are able to cool the air through water evaporation.

However, air coolers naturally increase the moisture in the air. In another word, they put more water vapor into the air. Hence, the humidity level in your house will increase as you use the air cooler.

In humid countries like Malaysia and Singapore, our air is already very humid (contain a lot of water vapor). Thus, the air has little to no room for additional water vapor.

Hence, air coolers don't work in high humidity countries.

“An air cooler put more moisture in the air to bring down the temperature until the room becomes too humid, it stops working.”

But, in low humidity countries (dry climate), air coolers work effectively because the air has room for additional water vapor. In fact, people living in dry climates have dry lips problems. So, air coolers increase the humidity level and help them to reduce dry lips problem.

How Air Conditioners Work?

Air conditioners work very differently from air coolers. Air conditioners are an engineered product. In technical terms, air conditioners work using the refrigeration cycle to transfer heat from indoor to outdoor.

Air conditioners do not produce cold air. Instead, they transfer heat from indoor to outdoor via a refrigerant thereby provide cooling to the house.

A typical split air conditioner
Air conditioner working diagram

Heat is absorbed by the refrigerant inside your house from the indoor unit. Then, the refrigerant travels to the outdoor unit where the heat gets rejected to the surrounding ambient air.

“An air conditioner absorbs heat in the house and reject it outside to cool the house. It works regardless of the humidity level.”

Unlike air coolers, air conditioners don't need us to constantly refilling the water. Air conditioners don't consume water. Rather, they are designed to remove moisture in the air thereby reducing the humidity level and create a more comfortable environment.

Should You Buy an Air Cooler?

If you are living in humid countries like Malaysia and Singapore, you are better off buying a more expensive air conditioner than using a less expensive air cooler that doesn't work.

As I mentioned earlier, air coolers can't work effectively when the indoor humidity level is high. Countries like Malaysia and Singapore have an average humidity level of around RH 85% which air coolers can't work.

RH stands for relative humidity which is expressed in percentage. It's used to measure the amount of moisture in the air at a given temperature.

Previously, I got a friend who bought an air cooler for his living room. The other day, I visited him in the afternoon at his house. He turned on his brand new air cooler and at first, it provides some cooling. But after about 20 minutes, my friend thought that his air cooler malfunction because the air coming out from his air cooler is not cool at all. So, I explained to him that his air cooler can't cool anymore because his living room is at maximum humidity (RH 100%) already. He ended up using his air conditioner and we all got so much more comfortable.

“Air coolers don't work in high humidity places.”

Below is a table showing the estimated time needed for a typical home air cooler (evaporation rate: 0.6 L/hr) to bring the room temperature of a typical 290 sqft room down from 30°C (86°F) to 25°C (77°F) based on different humidity levels:

Room Condition (Before)Room Condition (After)Time Needed
30°C (86°F)
RH 5%
25°C (77°F)
RH 15%
20 Minutes
30°C (86°F)
RH 10%
25°C (77°F)
RH 22%
20 Minutes
30°C (86°F)
RH 15%
25°C (77°F)
RH 30%
20 Minutes
30°C (86°F)
RH 20%
25°C (77°F)
RH 35%
20 Minutes
30°C (86°F)
RH 25%
25°C (77°F)
RH 43%
20 Minutes
30°C (86°F)
RH 30%
25°C (77°F)
RH 50%
20 Minutes
30°C (86°F)
RH 35%
25°C (77°F)
RH 58%
23 Minutes
30°C (86°F)
RH 40%
25°C (77°F)
RH 65%
23 Minutes
30°C (86°F)
RH 45%
25°C (77°F)
RH 70%
20 Minutes
30°C (86°F)
RH 50%
25°C (77°F)
RH 77%
17 Minutes
30°C (86°F)
RH 55%
25°C (77°F)
RH 82%
20 Minutes
30°C (86°F)
RH 60%
25°C (77°F)
RH 90%
20 Minutes
30°C (86°F)
RH 65%
25°C (77°F)
RH 98%
22 Minutes
30°C (86°F)
RH 70%
25.5°C (77.9°F)
RH 100%
20 Minutes
30°C (86°F)
RH 75%
26°C (78.8°F)
RH 100%
15 Minutes
30°C (86°F)
RH 80%
27°C (80.6°F)
RH 100%
13 Minutes
30°C (86°F)
RH 85%
28°C (82.4°F)
RH 100%
10 Minutes
30°C (86°F)
RH 90%
28.5°C (83.3°F)
RH 100%
5 Minutes
Estimated evaporative cooling time needed for a typical 290 sqft room

As you can see from the above table, at RH 70% and above, air coolers are not able to bring the temperature down from 30°C (86°F) to 25°C (77°F). The higher the humidity level, the poorer the air cooler performance.

High Humidity: ~RH 85%

In humid countries like Malaysia and Singapore, the indoor humidity level is around RH 85%. If you use an air cooler, your room temperature can't fall below 28°C (82.4°F) most of the time.

Sometimes, the humidity level can drop to RH 70%. At a glance, you might think that you are fine with the air cooler bringing the room temperature down to 25.5°C (77.9°F).

However, after the air cooler brought the room temperature down to 25.5°C (77.9°F) at which, the room humidity level is at RH 100%.

Now, the air cooler is no longer able to cool anymore.

So, the temperature in your room will gradually rise back to 30°C (86°F) with the humidity level remains at RH 100%. You'll feel very uncomfortable due to the high humidity level.

Therefore, I don't recommend anyone to buy an air cooler if they are living in places where the humidity level is around RH 70% and above. In short, air coolers are not suitable for Malaysian and Singaporean.

Not only that, air coolers can cause mold and fungus growth problems.

Mold and fungus start to grow at RH 60%. The best humidity level for mold and fungus to grow is around RH 70%. Since air coolers naturally increase the humidity level in your house, they directly promote the growth of mold and fungus.

Mild Humidity: ~RH 45%

If you are living in places where the humidity level is around RH 45%, air coolers can be a good cooling option. However, they will eventually raise the humidity level in your house to RH 100%.

Once the humidity level in your house reaches about RH 95%, you hardly feel any cooling effect from the air cooler. So, even at RH 45%, a typical air cooler may only serve you for about 1-1.5 hours before your house gets too humid and it stops working.

So, I would not recommend using air coolers for indoor applications. For outdoor applications, it is fine because the high humidity air coming out from the air cooler will easily get replaced by new drier air.

Low Humidity: ~RH 20%

Countries like Algeria, Egypt, Sudan and Saudi Arabia are very dry and low in humidity. Hence, air coolers work fine in these places. However, if you are going to use them for several hours, your room will eventually get to RH 100% and the air cooler will stop working too.

Thus, you may need to open windows to let some dry air come in and replace the humid air so that the air cooler can continue to provide cooling to your room. But, your room will get warmer at the same time.

ChillWell AC Product Review
ChillWell AC Product Review

Nevertheless, air coolers are still a pretty good cooling solution in low humidity places, considering that air coolers are more affordable than air conditioners.

Conclusion

Air coolers are not suitable for humid countries such as Malaysia and Singapore. They don't work when the humidity level is high. So, air conditioners are the best cooling solution in a high humidity environment.

Air coolers increase the humidity level in the house which can cause mold and fungus growth problems since mold and fungus start to grow at a relative humidity of 60% and above.

In Malaysia, there are a lot of air conditioner brands in the market. Daikin, Panasonic and Mitsubishi are some of the top selling brands here. So, which air conditioner should you buy?

My Recommended Air Conditioners

If you are interested in buying new air conditioners in Malaysia, I got some recommendations.

In Malaysia, split unit air conditioners are the best type of air conditioner you can get. Portable air conditioners are cheaper but they are very noisy.

Myself is using Daikin FTK-Q series R410A inverter air conditioners but Daikin already stops selling their R410A models. So, I recommend the newer Daikin FTK-F series (click to view on Shopee) which is also inverter models but using R32 gas.

I covered why inverter air conditioners are worth the higher price in one of my blog posts which I encourage you to check out because I outlined 9 reasons why you should get the inverter model.

Nevertheless, if you are on a tight budget, Daikin FTV-P series (click to view on Shopee) is a pretty good choice. Many people use a non-inverter air conditioner in their living room since they don't use it that often anyway.

The reason why I recommend Daikin brand is because I've been using Daikin air conditioners for more than 5 years now and they have not given me a single problem (touch wood). That's why I have confidence in Daikin air conditioners.

My recommended air conditioners may not be the most expensive one but they are not the cheapest one either. We use air conditioners for more than 10 years. Hence, quality no doubt is very important but I also consider affordability just like everyone else.


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Yu Chang Zhen

I enjoy working on air conditioners and ventilation fans because Malaysia is a very hot country.

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