Aircon Size Guide for Singaporeans

Aircons come in different sizes, and each variation has some benefits and downsides. Some air conditioners can be too small for your home, while others can be too big and consume more power. Fortunately, LK Brothers are here to teach you how to choose aircon size and find the right balance and consumption rate for your air conditioner according to the size of your home.

This Aircon size guide will outline the importance of understanding Aircon unit sizes and the factors that should influence the size of your Aircon.

Aircon BTU Room Size Calculations

Singaporeans need to know how BTU calculations work to understand the cooling capacity of their air conditioners. BTUs (British Thermal Units) represent heat measurement. Thus, they are important compound units when it comes to air conditioner room cooling capacities.

Though these units and cooling concepts are complex for inexperienced users, there is a general yardstick that suggests that there are 20 BTUs in every square foot of space. It can give you a rough idea of the cooking capacity you need for your room.

Below is a table outlining some details about the right room sizes for different capacities of aircons:

Room SizeAC Form FactorCapacityIdeal Type
10m² – 20m²Small Capacity2kW – 3kW (avg. 2.5kW)Portable Air Conditioner
20m² – 30m²Small/Medium Capacity2.5kW – 5kW (avg. 3.5kW)Window Split Air Conditioner
30m² – 60m²Medium/High Capacity5kW – 8kW (avg. 6kW)Split Aircon System
60m² and aboveHigh capacity8kW – 10kW+ (avg. 9kW)Ducted Air Conditioner

Types of Air Conditioners and Ideal Room Size

outdoor aircon system

There are different variations of air conditioners, all with their features that make them unique. This section will cover some of these aircon, so you can understand how they work about your room size:

Smart Aircons

Smart aircons are newer edition air conditioners with advanced capabilities and cooling features. Unlike traditional aircons, smart aircons operate remotely. Thus, with the aircon app on your smartphone or tablet, you can adjust the temperature of the air conditioner, switch it on or off, and even generate your preferred cooling cycle.

These features all add up to make these types of aircon more convenient and accessible. Due to their modern framework, smart aircon saves energy, providing slightly lower power consumption compared to older models.

These air conditioners are ideal for small-medium-sized homes, as they provide the needed features to enhance comfortability. However, they can be quite expensive and also cost more to repair.

Mini-split Ductless Aircon

Mini-split ACs are not suitable for large halls or homes with large rooms and spaces. These aircon are ideal for small/medium-sized spaces. The general structure consists of a blower and an outdoor condenser, connected with a large pipe encasing the drain, refrigerator, and electrical lines.

Like most other aircons, mini-split ductless air conditioners save floor space within your home. They also help reduce overall energy costs, but they have a high installation price starting from $1,200. Thus, the price is on the higher side and not suitable for most people on a lower budget.

Central Air Conditioners

Central ACs are popular air conditioners known for their effectiveness when it comes to cooling down and dehumidifying indoor air. This aircon has a structure that sucks out warm indoor air through the ducts and pushes in cool air generated from within the air conditioner. Though these ACs are popular, they are not ideal for home settings. Central ACs are best used for entire buildings and company houses.

Though Central ACs are very effective, their overall build is unattractive, and they can be loud while actively working. On average, these types of air conditioners cost around $5,000, and an additional $3,000 to $8,000 for installation if you were to hire aircon installation services.

Window Air Conditioners

Unlike central air conditioners that are expensive, window units cost way less, starting from around $100 and up to $1,000+, depending on the cost of installation. As the name implies, window units sit on windows facing indoors, with their backs outdoors. Due to the structure of these window units, we recommend them for small spaces.

Window air conditioners are ideal for single rooms and office spaces. There are different variations of this aircon, with some operating like regular ACs and others working like smart ACs.

Though window ACs are effective at cooling the temperature of your home or office, they also have some hazards. You have to be aware that window ACs are prone to falling out if not fixed properly, and they can also cause fire outbreaks if they overheat too much due to mechanical errors.

Why The Right Aircon Unit Size Is Important

There are several factors to consider when buying an air conditioner. Below are some of the top reasons why it is crucial to get the perfect aircon capacity for room size:

Room Space

In Singapore, space is one of the primary factors when choosing aircon size for your room that should affect the size of your air conditioner. Do you have a big room? Are you going to power a whole building? A bigger room will require a higher capacity air conditioner.

Air conditioners are more efficient when operating within the right room size. When you turn on an air conditioner, it cools and dehumidifies your home in a timely and well-planned manner. However, you will run into some complications if you use a unit that is too large for your home. Larger units will cool your house within a shorter time and turn off without enough chance to dehumidify your home. This process reduces the indoor air quality of your room, making it too dry and prone to contaminants.

If you intend to cool your single-room apartment, opt for a portable air conditioner. It costs way less than others and gets the job done. You can get a bigger unit or central air conditioner to cool an entire building or office space.

Below is an overview showcasing the room sizes of Aircons and their other specs:

  • Small spaces up to 30 ft² (single rooms, small offices, etc.): 4,000 to 6,500 BTUs.
  • Mid-range Spaces up to 350 ft² (homes, offices, small trading shops: 7000 to 9,000 BTUs.
  • Large spaces up to 650 ft and above up to a maximum of 650 ft² (companies, big houses, etc.).

Energy Bills

While most complications from wrong aircon sizes in Singapore often occur with bigger units, buying a unit smaller than your room size also has its flaws. If your aircon unit is too small, it will run round-the-clock. This occurs because these smaller units take much longer to cool a big room and end up running for extended durations.

This situation can drive up your energy bills to higher numbers, as consistent power consumption can quickly add up to big numbers in the long run.

Repair Consistency

You save yourself from additional expenses when you buy an Aircon that matches your room size. An Aircon unit bigger than your room size will start and shut down more frequently. It leads to a shorter lifespan due to the excessive looping cycles. At the same time, an aircon that is too small for your room will overhaul itself to meet the perfect temperature levels, leading to extended working time and further complications in the long run. These all lead to more frequent aircon repairs, as the operational specifications of the unit will not match the factory-defined limits.

Other Types Of Air Conditioners

Other than the aircon outlined above, there are also some other types of aircon that you can use for your home or workspace. Some of them are:

  • Wall Air Conditioners (Fixed through the wall and suitable for home settings).
  • Geothermal ACs (Highly efficient for apartments without huge yard spaces, but they have high installation prices).
  • Evaporative ACs (Suitable for small homes, but they work with ice and cold water, so you have to refill them always).

Tips To Get The Best Out of Your Aircon Size

Below are some tips we have compiled to help you reduce the workload on your aircon:

  • Use Portable Air Conditioners

If you live in a small apartment in Singapore and intend to get the most out of your air conditioner, you must opt for a portable air conditioner. These air conditioners operate just like every other electronic gadget in your home. They allow you to move them wherever you want. Unlike other traditional air conditioners, portable ACs cost between $200 and $1,000, and they are very easy to install. Thus, you will save more money getting these machines.

These portable ACs are also ideal for users who live or work in rented houses or office spaces. They can easily be moved, giving users the chance to enjoy a more flexible air conditioning experience.

  • Install Insulation Walls/Ceilings

Insulation is one of the best ways to reduce your air conditioner’s workload. Since insulation prevents much heat from reaching inside a building, it becomes easier for the air conditioner to remove the small amount of warm air and replace it. Insulated walls also help retain a room’s cool temperature level. Thus, it is one of the top options to help keep your Air Conditioner usage minimal.

You can also consider using the right window shades and ventilation to maintain a cool room temperature.

  • Use Energy-saving appliances

High-power appliances and bulbs often consume a lot of power, generating slow and steady heat, especially in the case of bulbs. We recommend ensuring you go for energy-saving appliances, as they operate without many heat-causing activities.


From the above so far, we hope you are now able to understand what size aircon to choose what for size rooms. At the end of the day, the best aircon size for you boils down to your personal preferences and the physical attributes of the space available.

For bigger spaces, a more ideal size would be a high-capacity central AC or a split Aircon System. On the other hand, smaller spaces only require portable air conditioners, mini-split ductless aircon, etc. To get a fast and quick estimate of your cooling measurements, you just need to calculate the volume of your room in square feet and find out the result of 20 BTUs representing each square metre.

Overall, this guide aims to not only show you some information about aircon sizes but also showcase how they work and the different variations available.

LK Brothers provides aircon chemical wash, overhaul, and troubleshooting services for all air conditioners in Singapore. Talk to us today!

FAQs About How To Choose Aircon Size

Below are some of the most-asked questions about aircon sizes:

What is the lifespan of an air conditioner?

The lifespan of an aircon depends on several factors including the manufacturer, form factor and the type of AC. But typically, aircons last between 15-20 years, often coming with a two-year warranty as soon as you make a purchase.

What is the best aircon size I can use in a small room apartment?

If you own a small space, opting for portable ACs is the best option. These units have designs that match single rooms and also have several variations that match different price points.

How to calculate aircon room size?

Calculate the volume of your room by multiplying the length and the width. At this point, you can then calculate cooling capacity by calculating an average of 20-40 BTUs in each square foot.

Are central ACs the best?

It is impossible to select a specific type of aircon as the best amongst all. Each type of aircon comes with its advantages and disadvantages. Thus, while central ACs are very efficient and complete with the house-cooling package, the best AC for you will depend on your budget, the climate of your region and also the maintenance cost.