electric

How to Calculate Air Conditioner BTUs per Square Meter

Mardey Costa
Escrito por Mardey Costa em 16/07/2023
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Discover step-by-step how to calculate the total amount of BTUs for an air conditioner per square meter, per person, and per appliance.

So if you want to learn more about this topic, keep reading this article.

This article was written in Portuguese and translated into English. Click here to check the original version.

How to Calculate Air Conditioner BTUs per Square Meter

Before explaining how to calculate air conditioner BTUs per square meter, it’s important to explain what BTU is.

BTU stands for British Thermal Unit, which is a unit of measurement used in the English system to measure the cooling power of a specific appliance.

In practice, BTU measures the amount of energy required to raise or lower the temperature.

Now let’s learn how to calculate the required BTUs for each room.

Calculating BTUs for Rooms

To calculate the BTUs required for an air conditioner, it’s important to consider the average temperature of the region, the size of the room that will receive the air conditioner, the solar orientation of the room, and even the number of people and electronics present in the room.

In general, we consider:

  • 600 BTUs for each square meter;
  • 600 BTUs for each additional person;
  • 600 BTUs for each electronic appliance;

In this case, let’s provide an example of a room with low sunlight exposure, such as morning sunlight.

Calculating Air Conditioner BTUs per Square Meter in a Bedroom

In this example, let’s consider a room with an approximate size of 12 square meters.

We’ll also assume that two people will be sleeping in this room every day.

Additionally, there are two electronic appliances in the room, a television, and a computer.

So, what will be the total BTUs required for the air conditioner in this room? Let’s find out.

600 BTUs per square meter

In the first step, we know that the room has approximately 12 square meters.

In this case, we’ll need around 600 BTUs for each square meter.

So, we multiply 12 square meters by 600 BTUs to find the total required BTUs.

In practice, this means that an air conditioner with at least 7,200 BTUs would be necessary.

However, it’s important to consider the two electronic appliances in this room as well, so let’s include them in our calculation.

600 BTUs per appliance

As mentioned earlier, the room has two electronic appliances, a television, and a computer.

For each appliance, we need to consider an additional 600 BTUs.

So, we need to add 1,200 BTUs for the two electronic appliances in this room.

This means that, in practice, we would need a total of 8,400 BTUs so far.

But before finalizing, we also need to consider the number of people in this room. Let’s do that.

600 BTUs per additional person

Until now, our calculation is based on 8,400 BTUs for this room.

However, we must not forget that two people will be sleeping in this room every day.

Therefore, we need to consider an additional 600 BTUs for each additional person.

In this calculation, we don’t consider the first person.

Since we have two people, we consider one additional person in our calculation.

This means that we need to add another 600 BTUs to our previous calculation.

So, how many BTUs are required for this room? Let’s find out.

Total BTUs required for the Bedroom Air Conditioner

If our 12-square-meter room requires at least 7,200 BTUs and has two electronic appliances that require an additional 1,200 BTUs.

And we also need to add 600 BTUs for one additional person.

In practice, this room would require an air conditioner with at least 9,000 BTUs.

But before we conclude this calculation, it’s important to note the following observation.

Important Note about BTUs

In the beginning of this article, we provided an example of a room with low sunlight exposure.

In this case, an air conditioner with 9,000 BTUs was sufficient for this room.

However, if we consider that the air conditioner will be used during a period of high sunlight exposure, the calculation will be different. Let’s see below.

Calculating BTUs per Square Meter with High Sunlight Exposure

For a room with high sunlight exposure, it is recommended to consider an increase of at least 800 BTUs.

This means the following:

  • 800 BTUs for each square meter;
  • 800 BTUs for each additional person;
  • 800 BTUs for each electronic appliance;

To facilitate understanding, let’s use the same example as before.

Calculating BTUs for the Bedroom Air Conditioner

In this case, let’s consider the example of a 12-square-meter room with high sunlight exposure.

We’ll also assume that two people will be sleeping in this room every day.

Additionally, there are two electronic appliances in the room, a television, and a computer.

So, what will be the total BTUs required for the air conditioner? Let’s find out.

800 BTUs per square meter

In the first step, we know that the room has approximately 12 square meters.

In this case, we’ll need around 800 BTUs for each square meter.

So, we multiply 12 square meters by 800 BTUs to find the total required BTUs.

In practice, this means that an air conditioner with at least 9,600 BTUs would be necessary.

However, we must also consider the two electronic appliances in this room, so let’s include them in our calculation.

800 BTUs per appliance

As mentioned earlier, the room has two electronic appliances, a television, and a computer.

For each appliance, we need to consider an additional 800 BTUs.

This means we need to add another 1,600 BTUs.

In practice, we need to sum up the previous 9,600 BTUs with the additional 1,600 BTUs, resulting in a total of 11,200 BTUs.

But before finalizing, we also need to consider the number of people in this room. Let’s do that.

800 BTUs per additional person

Until now, our calculation is based on 11,200 BTUs for this room with high sunlight exposure.

As we did in the beginning of this article, we must not forget that two people will be sleeping in this room every day.

Therefore, we need to consider an additional 800 BTUs for each additional person.

In this calculation, we don’t consider the first person.

Since we have two people, we consider one additional person in our calculation.

This means that we need to add another 800 BTUs to our previous calculation.

So, how many BTUs are required for this room? Let’s find out.

Total BTUs for a Room with High Sunlight Exposure

If our 12-square-meter room requires at least 9,600 BTUs and has two electronic appliances that require an additional 1,600 BTUs.

And we also need to add 800 BTUs for one additional person.

In practice, this room would require an air conditioner with at least 12,000 BTUs.

Now, pay attention to the following guidelines.

Important Note about BTUs

In the examples above, we considered a room with low sunlight exposure and determined that an air conditioner with 9,000 BTUs was sufficient.

However, if the chosen room is highly exposed to sunlight, the recommended air conditioner capacity would be 12,000 BTUs.

But keep in mind that these examples are for residential environments. For other cases, it is recommended to consult a professional in the field.

Seek an Experienced Professional

It’s important to highlight that the calculations provided are based on a room with a standard ceiling height of approximately 2.6 to 3 meters.

If the room to be air-conditioned has a higher ceiling or a large number of people, it is recommended to seek a thorough evaluation by technical professionals, engineers, designers, and architects in the industry.

This is crucial because, in the dimensioning of high thermal loads, it is necessary for the professional to consider other variables in the calculation.

Now, what would be the best air conditioner for this room? Let’s make a recommendation.

Best Air Conditioner for this Room

In this case, considering the first example with low sunlight exposure, the LG Dual Inverter Voice Split Air Conditioner with 9,000 BTUs is an ideal choice for bedrooms.

The image below shows the model S4-Q09WA51A with 220 Volts.

[Image of the LG Dual Inverter Voice Split Air Conditioner]

But why is this model ideal for bedrooms? Let’s explain.

Why LG Dual Inverter Voice?

There are several air conditioner brands on the market, but one of the best and most economical options is LG.

In practice, the aforementioned air conditioner is a good choice for small bedrooms or apartments and can be managed through Wi-Fi.

Regarding the mentioned air conditioner model, it is available on the Mercado Livre website for only R$ 2,341.00.

Additionally, it’s important to choose more energy-efficient models with inverter technology. Let’s see why.

LG Dual Inverter is More Energy-Efficient

In this case, it’s also important to note that models with inverter technology are much more energy-efficient compared to traditional models.

According to LG, the dual inverter compressor’s dual rotor balance ensures greater stability and reduced vibration, as shown in the image below.

Furthermore, LG states that this air conditioner model can save up to 70% of energy and provide cooling up to 40% faster, thanks to a wider range of speed control.

Another important feature of this type of equipment is that LG offers a 10-year warranty for this product.