Pros and Cons: Split System Air-Conditioners in Malaysia

Home » Pros and Cons: Split System Air-Conditioners in Malaysia

The penetration of ductless air conditioning split systems into the market is not uncommon to most. We have seen many of these wall mounted or ceiling cassette units in buildings.


In this short blog post we will dive into the various advantages and disadvantages of split system air-conditioning.


Wall mounted split air-conditioning


Advantages of Split Systems

There are a plethora of advantages that has propelled the adoption of split systems. These include but are not limited to:


1. Occupant Climate Control

The tropical Malaysian weather is highly unpredictable. At one moment, it may be 2 p.m. in the afternoon with the blazing hot sun. Suddenly 30 minutes later, there is a heavy downpour. When it is raining outside, occupants will feel too cold if the air conditioning system is set to maintain a temperature of 24°C.

Do we need a supply air temperature of 24°C when it is raining outside? No, we do not.

Instead, occupants will usually turn up the thermostat so that they maintain a comfortable environment without needing additional layer of clothing.

Occupant climate control is a step toward reducing the overall HVAC energy consumption.


2. Technical Skills Not Required

Split systems do not require a specialised set of skills to design, install, maintain and uninstall. Technicians do not need to undergo years of theoretical and practical HVAC training before they are equipped to install and perform maintenance of the split systems.

The simplicity of installing a split system is so evident that there are an innumerable D.I.Y. guides online.

The lack of technical skills required also reduces the annual maintenance costs required to service the air conditioning systems.

On the other hand, a centralised HVAC unit will require technical engineering design specialties. On top of that, servicing and maintaining these systems require skilled technicians. These costs can add up quickly.


Ceiling cassette split unit air-conditioning in a modern office setting


3. Flexible

Split system air conditionings are versatile and flexible. They do not require the installation of ducts. This is why split systems are also known as ductless air conditioning systems.

These systems are driven by an external compressor that is located outside, either on the ground or on brackets attached to an outer wall.


4. Quiet

While one of the primary drawbacks of traditional systems is the amount of noise they make within the home, split systems are nearly noiseless. This is a result of innovative engineering by the split system manufacturers.

Certain split systems by manufacturers have their indoor units rated at 19 dB. To put things into perspective, a whisper is rated at 20 dB [1].

Maintenance is advised if you notice your split air-conditioning is making loud noises. Alternatively, check the manufacturer’s specification regarding the sound rating.

Split system interior units are rather quiet, however the compressor unit positioned outside may make quite a bit of noise. This noise ranges from 50-70 dB depending on the location of the compressor from the observer.


Disadvantages of Split Systems

Just like any engineering systems, the split system air conditioning also contains inadequacies. These include but are not limited to:


1. The Constant Recirculation of Air

The Covid-19 pandemic has exposed the world to concepts such as indoor air quality (IAQ) or indoor environment quality (IEQ). Split systems are amazing at recirculating air. However their performance is severely negatively impacted when introducing outdoor air into the system.

Transmission of airborne pathogens in indoor environments can be reduced by diluting the indoor environment with outdoor air. This is something that split systems are not capable of performing efficiently. Hence why, split systems are not used in healthcare settings.


2. High CO2 Levels Are Unavoidable

If you place many occupants in a room, you may design for the cooling load to be achieved through the split system, but the split system cannot replace the CO2 in the indoor atmosphere.

CO2 levels are reduced by increasing the outdoor air supply to the indoor environment. Similarly as what was mentioned in the previous point, the inability for split systems to bring in fresh air can cause uncontrollably high CO2 levels.

High CO2 levels above 1000 ppm is uncomfortable and should be avoided according to ASHRAE.

Thus why split systems are never used in large auditoriums or concert halls.


3. Limited Filtering Options

The presence of airborne diseases such as Covid-19 has highlighted the importance of proper filter selection. ASHRAE recommends MERV 13 filters to be used [2].

These MERV 13 filters are recommended because they strike the balance between filter effectiveness and cost.

Unfortunately, most split systems are not able to accommodate MERV 13 filters. These include wall mounted split unit and ceiling exposed split unit.

Ceiling cassette split unit systems have the additional option to install MERV 13 filters.


The aesthetics of interior design can be maintained through intentional selection of split unit air-conditioning design


4. Aesthetics

Although many do not notice the presence of split unit air-conditioning systems in a building, some may not prefer seeing a wall mounted split system hanging on the wall.

If you do not want to see a wall mounted air-condition hanging from your wall, there are alternatives such as one-way ceiling cassettes, four-way ceiling cassettes or ceiling ducted types.

If you are an interior designer in Malaysia interested to find alternatives to air-conditioning systems for your design, perhaps you should consult an M&E consultant.

Perunding JW has worked with a plethora of interior designers, and we can assist you in your project.


5. Compressor Requires Space

The outdoor unit, also known as the compressor must be placed strategically according to the manufacturer’s guidelines [3]. The compressor must have full access to the outdoor environment. This means, there cannot be obstructions near the compressor.

A badly strategically placed compressor can reduce the efficiency of the split unit.

On top of that, a badly strategically placed compressor can end up blowing hot air even when the cooling mode is turned on. This problem commonly occurs due to poor installation and design.



There is no one-size fit all solution for air-conditioning systems. Hence why, there is a comprehensive range of HVAC equipment in the market. Each of these various systems have a wide range of pros and cons. The best solution for you depends on your needs and requirements.


Perunding JW is an M&E Consulting firm based in Malaysia. If you are looking for more information or resources, reach out to our team of engineers. We will gladly assist you. Visit our homepage or call us at +603 7955 5918.



[1] Daikin Australia Pty Limited, “The noise factor: why it’s important both indoors and out”, Daikin, 2022. [Online]. Available: [Accessed: 09- Feb- 2022].

[2] ASHRAE, “Filtration / Disinfection”,, 2022. [Online]. Available: [Accessed: 09- Feb- 2022].

[3] Daikin Industries Czech Republic, “Outdoor Unit Installation Manual”,, 2010. [Online]. Available: [Accessed: 09- Feb- 2022].

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