In a hot and humid country like Singapore, air conditioners have become a necessity. Not only do they cool your room by removing heat, but they also eliminate microorganisms, creating a more comfortable and cleaner living space.
If you’re planning to purchase an air conditioner, choosing the right BTU is just as important as staying within your budget. With the correct BTU in your aircon, you can ensure your room cools efficiently while optimising electricity use.
Here, we’ll dive into BTU in air conditioners and a guide to choosing the right one based on your room size. Read on to learn more!
When you’re browsing through air conditioners online or offline, you may have come across BTU 9000, 12000, and even 18000. But what does this actually mean?
British Thermal Unit (BTU) measures how much energy an air conditioner uses to remove heat in an hour. A higher BTU rating means an aircon unit can cool larger space, making it ideal for bigger rooms.
While a higher BTU rating means greater cooling power, it isn’t always better. You should match your aircon’s BTU rating with your room size, ensuring effective cooling without compensating for the electricity use and cycling frequency.
There are several consequences that will arise if your aircon’s BTU rating doesn’t match your room sizes, as explained below:
Choosing an air conditioner with a higher BTU rating than needed can result in energy overconsumption, leading to higher electricity bills. Besides, an oversized aircon also tends to cycle on and off too frequently, potentially shutting down before achieving proper cooling and trapping moisture–resulting in a humid room.
Such frequent on-and-off cycling also accelerates the unit’s wear and tear, causing it to break down more quickly. This not only shortens your AC’s lifespan, but also exhausts your money on repairs or replacement.
An undersized aircon’s BTU rating isn’t any better. It can cause your AC to overwork in trying to cool a large room, yet it’s unable to reach the optimal temperature, often leading to unit damage.
Aside from that, an overworked unit will also result in extra energy consumption by the cooling system. If you think you’re saving on electricity bills by opting for an undersized AC instead of an oversized one, think again–it can also drive up your bills due to its inefficiency.
Different room sizes call for different BTU ratings. Make sure that you choose an aircon unit with just the right BTU score, not too high or too low. This will ensure that your room achieves effective cooling without compensating for energy uses and the unit’s wear and tear.
| Room Types | Room Sizes | Recommended BTU |
| Bedroom | 11 – 14m2 | 9,000 |
| Large Bedroom | 15 – 20m2 | 12,000 |
| Living Room | 14 – 18m2 | 12,000 |
| Kitchen | 9 – 11m2 | 9,000 |
| Small Office | 11 – 14m2 | 12,000 |
| Medium Office | 18 – 24m2 | 14,000 |
| Larger Office | 27 – 35m2 | 18,000 |
While room sizes provide a helpful guide in determining the ideal BTU rating, you should also take into account other factors to ensure an effective cooling mechanism in your home or office. These include:
A higher ceiling increases the amount of air volume that needs to be cooled inside your room. The rule of thumb is, you should add 25% more of BTUs for each additional foot of ceiling height higher than 8 feet (2.4m).
For example, a 14m2 room with up to an 8-foot ceiling would need a 9000 BTU air conditioner. However, if the room has a 10-foot (3m) ceiling, you would need to add 50% of the BTU requirement, making the ideal BTU rating to be 13,500 (9000 + 50%).
Larger windows, especially those that face the sun, impact the room’s heat during the day. In this case, upsizing your aircon’s BTU rating can be beneficial as the cooling mechanism remains effective.
The key is, you should add 10% of BTUs if your windows are covered with blinds, and 20% of BTUs if your windows are exposed to direct sunlight.
For example, a 24m2 medium-sized office with several clear windows exposed to direct sunlight, could benefit from a 20% BTU upsize. This makes the ideal BTU rating to be 16,800 (14,000 +20%).
The number of people in a room impacts the heat accumulation. Each person generates body heat, equivalent to 300 BTUs/hr, which can increase the cooling demand from an air conditioner.
This is why the aircon’s BTU rating should also be adjusted to the number of occupancies. For instance, a 14m2 room alone requires an aircon with 9,000 BTU to cool the space effectively while accommodating 2 people comfortably.
However, with 6 occupants, the BTU requirement increases. An additional 1,200 BTUs (300 BTUs × 4 extra people) should be added to the standard, resulting in a total requirement of 10,200 BTUs to ensure optimal cooling for 6 people.
Heat-generating appliances, such as stoves, ovens, and microwaves increase the heat accumulation inside a room. This is why a kitchen often requires a greater aircon BTU rating, even when its size is similar to a small bedroom.
The general rule of thumb is to add 2,000 BTUs above the standard requirement. For instance, a 9m2 kitchen, unlike an ordinary room that would require just 7,000 BTUs, should have 9,000 BTUs to ensure proper cooling.
To measure the electricity usage, you should first identify how many kilowatt-hours (kWh) are in one BTU and multiply it by your aircon’s BTU ratings. With 0.000293 kWh in one BTU, an aircon with 6000 BTU would consume 1.758 kilowatts in an hour.
Now let’s assume that the aircon operates for an average of 7 hours every day for a month. Here’s the amount of energy it would consume:
1.758kw x 7 hours = 12.306 kWh per day
1.758kw x 7 hours x 30 days = 369.18 kWh per month
Next, you would need to calculate the total kWh consumption to electricity tariff in your area.
For example, in Singapore, it’s 31.72 cents per kWh. With an average usage of 7 hours per day for a month, the total bills would approximately be $117.10/month.
Choosing air conditioners with the right BTU rating ensures that your rooms achieve proper cooling in your space. You can also reduce the potential of unit damage or energy overconsumption that can reduce your aircon’s lifespan or increase your utility bills.
Here at North East, we can help you select the ideal air conditioner BTU rating for your needs. We’ve made the process simple and convenient, whether you’re a homeowner, contractor, or dealer.
Contact us today. We are ready to provide you with aircon solutions that truly work for your needs!
Neither is good. You need to make sure that your aircon has an ideal BTU rating based on the room’s size, along with other factors like ceiling height, occupancy, sun exposure, occupancy, and the presence of other appliances.
When your air conditioner’s BTU rating is too high, it will lead to energy overconsumption, which increases your bills. Besides, this can also cause moisture to be trapped, causing a humid room.
To calculate your aircon consumption in an hour, you would need to multiply the BTU rating by 0.000293 kWh.
A 9,000 BTU air conditioner is enough to cool a small-medium bedroom, sized between 11 – 14m2.
