What Size Mini Split Do I Need?

What Size Mini Split Do I Need?

To stay comfortable year-round, you need to know the ins and outs of sizing mini split systems. Pay particular attention to the mini split BTU per square foot of the unit. 

Here are the top factors to steer you in the direction of the right mini split. 

Square Footage

Calculate the square footage of the room you’re trying to heat and cool, and then multiply that number by 25 to get the correct BTU rating required. 

Understand BTU ratings 

Mini split btu size is critical to the function of your unit. BTUs let you know how much energy your mini split is using to do what you need it to do. For example, a 12,000 BTU unit absorbs 12,000 British Thermal Units of heat per hour and moves that number outside to keep your inside space comfortable. 

Ceiling Height 

For standard ceilings around 8 feet, standard BTU recommendations are applicable. For high ceilings taller than 8 feet, a larger BTU capacity is required to make up for the extra air volume in the space. 

Doors and Windows 

Oversized windows and poor insulation will have your min-split working overtime. The number of inside/outside doors in your space also affects the efficiency of the unit. Consider those when shopping for mini splits. 

Sunlight Exposure 

South/West facing rooms have more heat gain and could require a greater capacity to heat or cool. On the other hand, shaded or north-facing rooms may require less capacity to heat or cool.

Mini Split Sizing Chart

Mini Split Sizing Chart

Frequently Asked Questions About Mini Split Sizing

Have more questions about mini split sizing? Check out these frequently asked questions and answers. 

How do I calculate what size mini-split I need?

Step 1. Gather your square footage information. Step 2. Multiply your square footage by 25 to determine the appropriate number of BTUs required. 

Is it better to undersize or oversize a mini-split?

In general, it is better to undersize rather than oversize your mini split. Oversized units are inefficient, thanks to a shorter cycling schedule. 

How many square feet will a 12000 BTU mini-split cool?

Most 12,000 BTU mini split's can heat and cool around 450-550 square feet. This is approximately the size of a studio apartment. 

How many square feet will a 24000 BTU mini-split heat?

1,000 to 1,500 square feet. 

How many mini splits do I need for 1500 square feet?

You would need either one mini split with around 30,000 BTUs or two 15,000 BTU units. 

What is the difference between 9000 and 12000 BTU mini split?

9,000 BTUs would cool smaller spaces around 200 square feet. A 12,000 BUT unit would cool a larger space, around the size of a studio apartment. 

How many square feet can a 6000 BTU mini split cool?

6,000 BTU mini split's can cool around 250 square feet. 

Can one mini split cool a whole house?

Yes, if you get the appropriate size to match your square footage. 

What size mini split for 600 sq ft garage?

For a one car garage, around 9,000 BTUs is sufficient. The larger the garage, the more BTUs you’ll need.

How many sq ft will a 18,000 BTU mini split cool?

Up to 750 square feet.