When you are looking to buy a mini-split for your house, you must go for the right-sized mini-split as it influences everything. They are termed as one of the most efficient HVAC solutions in the market owing to their inverter technology. Due to the technology, mini-splits are known to produce the required amount of heating or cooling that is necessary for your room to maintain the temperature settings.
A correct-sized mini-split heater pump is necessary for the performance. It can effectively and efficiently heat or cool your house. So, the BTU rating is important when choosing the system.
However, mini-splits can be difficult to choose when considering the size of the room. Through this article, we will discuss the right way to calculate the correct mini-split that is suitable for your room.
What are the Factors Needed to Size the Mini Split?
There are several factors that you need to keep in mind while choosing the properly-sized mini-split for your home. The BTU capacity is not the only consideration as you need various external factors for your mini-split. We have discussed the factors in this section.
1. Dimensions of the Room
The first major consideration to remember is the size or the dimensions of the room in which you want to install the mini-split system. For that, you have to look at the square feet of the room and also the ceiling height. The details on how to take the square feet are elaborated on in a section later.
Now, for the ceiling height, high ceilings make the room bigger. So, the standard ceiling height for a room is 8 feet. If the ceiling of your room is higher, then make sure that the BTU of the system you are purchasing is increased by at least 20%.
2. Number of Windows
Another important factor that influences the choice of the BTU capacity is the number of windows and doors in the room. The doors and windows are not insulated, which allows the air to escape from the small gaps or cracks of them. Therefore, it influences the BTU capacity, and you should go for a system with higher BTUs.
3. Number of People In the Room
People in the room generate heat which will influence the cooling or heating of your mini-split. So, for the mini-split system you are installing, you need to consider the usual occupants in the room where you are looking to install the mini-split system. This will enable you to use the correct BTU capacity for your mini-split.
4. Building Age
The age of the building you are living in is an important consideration as the newer constructions have enhanced insulation compared to the older ones. So, if the building you are living in is old, you should increase the BTU by at least 30% to make the room comfortable. Again, fewer BTUs are needed for newer constructions and newer homes with better insulation.
5. ZIP Code
The ZIP code will determine the climate that you are living in, which will influence the temperature inside the house. The colder or hotter weather you live in will impact the choice of the right-sized mini-split system. If you live in a place with a temperature of more than 90 degrees, the BTU rating should be increased by 30% at least.
6. Insulation of the House (Poor, Good, Excellent)
Insulation of the room highly influences the BTU capacity of the mini-split that you should go for. Rooms with better insulation prevent the air from escaping and hence fewer BTUs will do the job while rooms with poor insulation would need higher BTUs to effectively keep the room cool.
7. Room Type (Ground Floor, 1st Floor, 2nd Floor)
The upper-level floors remain hotter than the lower-level floors. So, the BTU capacity should be decreased if your house is on the ground floor and gradually increased as the floors increase.
How Do you Find the BTU with the Help of the Room Size In Square Feet?
After looking at the factors that will influence the BTU capacity of the room, you need to consider the general thumb rule for cooling or heating a room when buying the mini-split. Generally, 25 BTUs for each square foot is enough to cool or heat a room effectively.
So, if you are installing a mini-split for a room size of 260 square feet, then the BTU should be calculated as follows.
25BTUs X 260 sq ft = 6,500 BTUs
If you are living in colder places, you need to consider 30 BTUs for each square foot.
What are the Different Sizes of Rooms with Different Mini Split ACs?
In this section, we have listed the required BTU capacity that you should look for in case of different room sizes. Follow the table below to know more.
| BTU Capacity | Square Feet |
| 6,000 BTUs | Up to 260 sq ft |
| 9,000 BTUs | 240-390 sq ft |
| 12,000 BTUs | 360-500 sq ft |
| 15,000 BTUs | 480-620 sq ft |
| 18,000 BTUs | 600-750 sq ft |
| 24,000 BTUs | 720-1,000 sq ft |
| 30,000 BTUs | 960-1,240 sq ft |
| 36,000 BTUs | 1,200-1,500 sq ft |
| 42,000 BTUs | 1,440-1,740 sq ft |
| 48,000 BTUs | 1,680-2,000 sq ft |
| 54,000 BTUs | 1,920-2,240 sq ft |
| 60,000 BTUs | 2,160-2,600 sq ft |
This chart is generalised and you might need to alter the BTU capacity depending on the factors that are mentioned above.
Final Word
Choosing the right size of mini-split for your home should be achieved by the load calculator process. We have discussed all the details which you need to know when selecting the mini-split. These are critical to ensure that the mini-split can provide a comfortable and consistent temperature that is ideal for you.
With all the details, we think that choosing the right mini-split will be easier for you. If you still have queries or doubts, do mention them in the comments section below. Happy cooling!
