A Complete Guide To Ductless Mini-Split Sizing

A Complete Guide To Ductless Mini-Split Sizing

When choosing a ductless mini-split for your home, there are numerous different factors to consider, from the system’s energy efficiency rating to its aesthetic appearance. One of the most important features to think about, however, is the mini-split size. The size of your temperature control system will impact the lifespan of the system, how efficient it is, and how comfortable your home is, among other factors. To ensure that you choose the right sized system, take a look at this complete guide to ductless mini-split sizing.

The Importance of Choosing the Right-Sized Mini-Split

Before we begin discussing how to choose a mini-split that is properly sized for your space, it is important to understand why a correctly sized mini-split is necessary. As previously touched on, choosing an improperly sized mini-split will have several negative impacts on the comfort of your home, the lifespan of the system, and the efficiency at which the system operates. Below, we will discuss some of the main downsides to choosing a mini-split that is too big or too small. 

Consequences of Choosing a Mini-Split That Is Too Small

Perhaps the most obvious consequence of choosing a mini-split that is too small for your space is that the system will not have enough power to effectively heat or cool your home. Despite running at full-power, your house may never reach your desired temperature, as the system would be too small to heat or cool the space effectively. Thus, the comfort of your home will be significantly reduced as a result of a small system. 

Further, because the system will operate continuously at full-blast in a futile attempt to control the temperature of your home, the system will likely wear down more quickly. As a result, you will have to either pay the cost of more frequent repairs or ultimately just purchase a new system altogether.

Consequences of Choosing a Mini-Split That Is Too Large

Many people mistakenly believe that the largest and most powerful mini-split will be the most effective at heating or cooling their home. However, this is simply not true. When a mini-split system is too large for the space that it is placed in, it will often begin to short cycle. Short cycling refers to when a system repeatedly turns on and off within short periods of time.

This phenomenon occurs because the system has so much power which means it will quickly cool or heat the space to the desired temperature. Once the temperature is reached, it will completely shut off, only to power back on a short amount of time later. This cycle of powering on and off isn’t just noisy and annoying—it will also cause premature wear and tear on the system and reduce its energy efficiency.

Understanding How Mini-Splits Are Sized

Now that you have an understanding of why choosing the right sized mini-split is so important, it’s time to discuss how mini-splits are sized. Essentially, mini-split systems are sized in BTUs. The acronym BTU stands for British Thermal Units, which is a popular unit of measurement for energy in the United States. A BTU rating indicates the amount of energy necessary to increase the temperature of a pound of water by 1° Fahrenheit.

The higher the BTU rating a mini-split system has, the larger amount of energy it can provide. While there are many different factors that will influence the BTU rating that your system will need, the size of your space is the most significant. Naturally, a larger home will require a higher BTU rating, while a smaller space will require a lower rating.

General Mini-Split Sizing Chart

To get a general idea of what sized mini-split you will need for your space, consult the sizing chart below. This chart estimates appropriate mini-split sizes based on the square footage of individual zones. If you are considering installing a multi-zone system, you will need to combine the total amount of BTUs needed in order to determine the system’s overall BTU values.

It is important to note that the sizing guidelines listed below are just a rough estimate based on the size of your home alone. The exact ideal-sized mini-split for your home may be influenced by other factors which we will discuss later in this article.

Size of Zone

Recommended BTU Rating

150-250 sq. ft.

6,000

250-300 sq. ft.

7,000

300-350 sq. ft.

8,000

350-400 sq. ft.

9,000

400-450 sq. ft.

10,000

450-550 sq. ft.

12,000

550-700 sq. ft.

14,000

700-1,000 sq. ft. 

18,000

1,000-1,200 sq. ft.

21,000

1,200-1,400 sq. ft.

23,000

1,400-1,500 sq. ft.

24,000

Additional Factors To Consider When Determining Mini-Split Size

While the size of the zone you are heating or cooling has the largest impact on the ideal BTU rating, there are also other factors to consider. Keep the following considerations in mind when determining the size of mini-split you will need for your space:

  • Ceiling Height: The BTU rating recommendations above are based on the assumption that a home has 8-foot tall ceilings. If your ceilings are higher than 8 feet, you will likely need to look for a system with a higher BTU rating than the suggestion listed.
  • Quality of Insulation: How well your home is insulated will also influence the ideal BTU rating for your mini-split system. If your home is not well-insulated, cold and hot air will continuously enter or exit your home. As such, you will require a more powerful system with a higher BTU rating in order to keep the space at a desired temperature. 
  • Location of Household: The location of your home may also impact the size of the system that you will need. If your house is located in an area that has an extremely hot or cold climate, you will likely require a larger, more powerful mini-split system than you would if you lived in a mild climate.

Now that checked out our complete guide to ductless mini-split sizing and you have a general idea of what sized system you need, it’s time to find the perfect mini-split for your home. At the Pioneer Mini-Split Store, we offer a wide variety of easy-to-install, energy-efficient units. From ductless heat pump systems to multi-zone units, we will help you find the ideal mini-split for your needs. To learn more about our products, contact us or shop our extensive online collection today.

A Complete Guide To Ductless Mini-Split Sizing