Air conditioners work by moving heat from the indoors to the outdoors. The amount of heat that an air conditioner can move is called its cooling capacity. The cooling capacity of an air conditioner is expressed in British Thermal Units (BTUs) per hour. A BTU is a unit of measurement that equals the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit. The higher the BTUs, the greater the cooling capacity.

What Is Cooling Capacity In AC

Most residential air conditioners have a cooling capacity between 5,000 and 60,000 BTUs per hour. When choosing an air conditioner, it’s important to select one with the appropriate cooling capacity for your home. An air conditioner that’s too small will have to work harder to cool your home, while one that’s too large will cool your home too quickly, resulting in wasted energy and uneven temperatures.

What is BTU in AC

The British Thermal Unit (BTU) is an international unit of measurement for the amount of heat removed from (or added to) the environment in one hour.

It’s easy to believe that an air conditioner with more cooling power, and hence more BTUs, is always better, but this isn’t the case. The number of BTUs required is proportional to the size of the room to be cooled as well as other environmental parameters.

It’s critical to have an accurate understanding of the BTUs utilized to cool our home; otherwise, the air conditioner may work too hard and wear out prematurely.

So, how many BTUs would you require for your home? The table below will give you some idea.

Square MeterBTUCapacity
15                          5,0000.41 ton
23                          6,0000.5 ton
28                          7,0000.58 ton
32                          8,0000.67 ton
37                          9,0000.75 ton
51                          12,0001 ton
65                          14,0001.17 ton
92                          18,0001.5 ton
111                        21,0001.75 ton
130                        23,0001.92 ton
148                        25,0002.08 ton

It is obvious that, above a particular threshold, such as 80-90 square meters, two 1.5 ton window air conditioners or a single 2 ton split air conditioner are required.

Then there are several environmental considerations to consider while calculating BTU. If the air conditioner is to be installed in a naturally warm area, such as an attic or a room with large windows facing the sun, an additional 10% BTU must be calculated to compensate for the increased heat.

What is cooling capacity in AC in watts

The cooling capacity of an air conditioner can also be measured in watts. More powerful AC units will have higher cooling capacities in watts, as they are able to cool larger spaces more effectively.

1 BTU/hr = 0.29307107 W

Based on this formula, the following table will tell you how many watts and kilowatts of cooling capacity you need to cool your home.

Square MeterWattsKilowattsCapacity
15                          1,4651.50.41 ton
23                          1,7581.80.5 ton
28                          2,0522.10.58 ton
32                          2,3452.40.67 ton
37                          2,6382.60.75 ton
51                          3,5173.51 ton
65                          4,1034.11.17 ton
92                          5,2755.31.5 ton
111                        6,1556.21.75 ton
130                        6,7416.71.92 ton
148                        7,3277.32.08 ton

While bigger isn’t always better when it comes to ACs, a unit with a high-power output can be very useful for those who live in hot climates or simply want to keep their homes nice and cool during the summer months.

Choosing the right cooling capacity in watts will depend on your needs and preferences, so it’s important to do some research and consider factors such as your home’s size and how often you use your AC. Ultimately, however, a unit with a good cooling capacity can help ensure that you stay comfortable all summer long.

Factors that affect the required cooling capacity for your home

Several factors must be considered when determining the cooling capacity that is required for your home. The size of the room, the amount of sunlight it receives, the number of people that occupy the space, and the type of insulation are all important factors.

The climate in which you live also plays a role in the required cooling capacity. In general, homes in cooler climates require less cooling capacity than homes in warmer climates. Once all of these factors have been taken into consideration, you can then determine the appropriate cooling capacity for your home.

Remember that it is always better to overestimate the cooling capacity than to underestimate it, as this can lead to discomfort or even health risks. With a little careful planning, you can ensure that your home has the perfect amount of cool air for a comfortable environment.

1. Size of your home

The size of your home has a direct impact on the amount of cooling capacity required to keep it comfortable. The larger the home, the more cooling capacity is required. This is because a larger home has more space for heat to build up.

Additionally, large homes tend to have higher ceilings, which allows heat to rise and accumulate near the top of the room. As a result, it is important to choose a cooling system that is properly sized for your home in order to ensure optimal comfort. Luckily, there are a variety of air conditioners on the market that offer different levels of capacity, so you can find one that perfectly suits your needs.

2. Geographical location

Geographical location can have a significant impact on what kind of cooling system you need. For example, if you live in a hot climate, you will likely require more cooling capacity than someone who lives in a cooler climate. This is because temperatures in hotter regions tend to be more extreme, with highs that are well above average and lows that are much lower than normal.

In addition, these extreme temperature fluctuations also impact air quality and humidity levels, which can further increase your need for cooling capacity. Therefore, if you want to ensure that your home or office is properly cooled and comfortable year-round, it is crucial to consider geographical location when choosing your ideal air conditioning system.

3. Number of windows and their orientation

Given the importance of windows to a home’s energy efficiency and comfort, it is no surprise that their number and orientation are key factors in determining how much cooling capacity a house will need. Homes that have many windows or that face south tend to require more cooling during the summer months, as they allow the sun to stream in and raise the overall temperature of the interior.

Conversely, homes with fewer or north-facing windows will be able to stay cooler without requiring extensive air conditioning. This goes to show that while windows are typically seen as a desirable thing in a home, their positioning can make all the difference when it comes to controlling indoor temperatures.

So, if you’re looking for a cool and comfortable home during the sweltering summer months, be sure to consider how many windows you have, as well as where they are facing. By doing so, you’ll be able to ensure your home stays cool and comfortable year-round.

4. Level of insulation and airtightness

When it comes to creating a comfortable home environment, insulation and airtightness are two key factors to consider. Homes that are properly insulated offer more protection against weather fluctuations and can keep heat inside during the winter months. At the same time, homes with fewer air leaks tend to be more energy-efficient, as they are better able to regulate and retain indoor temperatures.

Therefore, if you want to create a comfortable, energy-efficient home, it is essential to focus on both insulation and airtightness. Whether you hire a contractor or choose to DIY your insulation project, remember that the level of insulation and the degree of airtightness will have a huge impact on your overall cooling capacity.

With proper planning and installation techniques, however, you can enjoy year-round comfort in your home without breaking the bank or consuming too much energy.

5. Usage patterns

How you use your home can have a big impact on your air conditioning needs. If your family is home during the day, you’ll need more cooling capacity than if everyone is out all day long. The same is true if you spend a lot of time in the living room or kitchen.

These areas generate heat, which will require the air conditioner to work harder to maintain a comfortable temperature. By understanding your usage patterns, you can choose an air conditioner that will meet your needs without excessive energy consumption.

6. Number of occupants  

When it comes to keeping your home cool during the summer months, one of the most important factors to consider is the number of occupants in your house. The more people living in your home, the more cooling capacity you’ll need to stay comfortable. This is because heat production increases with each person, and greater power output can quickly overwhelm even a large air conditioner.

Additionally, with additional occupants comes the potential for much higher energy usage, which can lead to higher overall utility costs. For these reasons and more, it is essential to keep an eye on the number of people living in your home and adjust your cooling system accordingly to ensure optimal performance and efficiency.


Cooling capacity is one of the most important factors to consider when choosing an air conditioner. It is a measure of the unit’s ability to cool your home and should be chosen based on the size of your home, the number of occupants, and your usage patterns. By understanding cooling capacity and how it works, you can ensure your air conditioner is able to keep your home cool and comfortable all summer long.

Frequently asked questions (FAQs)

1. What is the cooling capacity of 1.5 ton AC?

The cooling capacity of a 1.5 ton AC is approximately 18,000 BTU per hour. This refers to the amount of heat that an AC can remove from a space over time. In general, the higher the BTU rating of an AC, the larger its overall capacity and the more effective it will be at cooling a space.

2. Is higher cooling capacity better?

Higher cooling capacity generally results in better cooling performance. This is because devices with higher cooling capacity can typically cool larger spaces more effectively, and they also tend to have more features and better build quality. If you’re looking for the best cooling performance and efficiency, choose a device with high capacity.

3. What is 50% cooling capacity in AC?

It means that the AC is running at 50% capacity.  The other 50% is not being used. When an air conditioner is said to be running at 50% capacity, it means that only half of the unit’s potential cooling power is being used. The other half of the unit’s capacity is not being utilized.

4. What is the cooling capacity of 1 ton AC?

In general, 1 ton of cooling capacity for an AC is equivalent to 12000 BTU/hr. (British Thermal Units per hour). This means that the AC can remove up to 12000 BTUs of heat from a room in an hour. In watts, the cooling capacity of a 1 ton AC is 3,517.