How Big Is A Mini Split? Size, Capacity, and Dimensions

Thinking of switching to ductless heating and cooling? They’re great systems for superior comfort and energy efficiency. But, you may have some questions about how big a system you’ll need — and what it will look like in your home.


I can answer all your questions. I’ve been a product manager for Peirce Phelps, an HVAC distributor, for nearly 15 years, I’ve worked with all the latest high-efficiency equipment. And, I work closely with hundreds of certified contractors who install thousands of ductless systems, or mini splits, throughout Delaware, Maryland, Pennsylvania, and New Jersey.

You start here for basic information about how heat pump systems work. This article will answer all your questions about heating and cooling capacity as well as the physical size and appearance of a mini split for your home. If you have more questions, use our dealer locator to find a certified installer near you.

Our HVAC contractors offer free consultations and have worked in the area for years.


How Big Are Mini Splits?

Mini splits have a few options for components, which means there’s no one general size. I’ll go through all the parts here.

Heat Pump

The mini split heat pump is the outdoor unit that houses the compressor and condenser.


The dimensions of mini split heat pumps vary depending on the manufacturer and model. Generally, the smallest units are around 12x30x21 inches tall, wide, and deep to 32x40x16.


The weight of mini split heat pumps ranges from 50 to 150 pounds, depending on the size and manufacturer.

Air Handlers

The mini split indoor unit is known as the air handler. These units come in different styles and sizes. You can choose different ductless units, and where to install them, to suit you specific needs and aesthetics.


High-wall air handlers are the most common type of indoor unit for mini split systems. You see these rectangular panels mounted on the wall near the ceiling.


High-wall air handlers are typically around 12x30x10 inches tall, wide, deep.


High-wall air handlers weigh between 20 and 40 pounds depending on the size and features.


Low-wall air handlers are similar to high-wall units, but they are mounted closer to the floor. These units are ideal for rooms with low ceilings or limited wall space.


Low-wall air handlers are typically around 30 inches wide, 10 inches deep, and 18 inches tall.


Low-wall air handlers weigh between 25 and 45 pounds, depending on the size and features.

Recessed Ceiling

Recessed ceiling cassette air handlers are installed in the ceiling so you only see the vent. It lays flush against the ceiling.


Recessed ceiling air handlers are typically around 24×24 inches. They go about 8 inches deep into the ceiling.


Recessed ceiling air handlers weigh between 30 and 50 pounds.

Heating and Cooling Capacity: What Mini Split Size Do I Need?

A system that’s too big or too small (meaning, too strong or too weak) will never give you the right heating and cooling. It’s also likely to break down earlier than it should.

You’ll need a professional HVAC tech to perform a load calculation. I’ll get into the details below. But first, some general terms and estimations.

Mini Split Sizing

Here’s the quick guide to mini split sizing and capacity.


A mini split’s heating and cooling capacity is measured in BTUs (British Thermal Units). One BTU is the amount of heat needed to raise the temperature of one pound of water by one degree Fahrenheit.


EER, or Energy Efficiency Ratio, measures the cooling capacity of an air conditioner vs. its electrical power consumption. In other words, the less electricity it uses to do the job, the more efficient it is.

General BTU Sizing Guide

If you’re starting to look at models and prices, you can use this as a rough estimate before getting a load calculation. Generally, you can figure 20 BTU of heating or air conditioner for every square foot of space. With a mini split, you’ll go by the square footage of each room:

Single Zone Or Multi-Zone Setup

The biggest question about what equipment you’ll need is if you’re going with a single zone or multi-zone setup. A single zone system is ideal for a single room or area of your home, while a multi-zone setup can cool or heat multiple areas or rooms of your home.

Mini Split Sizing Factors

I mentioned that several factors need to be considered when sizing a mini split system for your home. Here they are:

Square Footage Of The Room

Since each air handler treats a different room, you’ll measure each room size rather than the entire living space.


A well-insulated room will require less cooling or heating capacity than a poorly insulated one. Insulation keeps warm air inside during the winter and stops the heat from getting in during the summer.


The layout of the room, including the location of doors, windows, and furniture, can impact the airflow and cooling or heating capacity of your mini split system.

Ceiling Height

The higher the ceiling, the more cooling or heating capacity you will need to effectively cool or heat the room.

Windows And Orientation

Rooms with more windows or windows facing south or west will require more cooling capacity than rooms with fewer windows or windows facing north or east.

Mini Split Sizing FAQs

Here are a few more FAQs and answers. If you need more specific information, use our dealer locator to set up a free consultation with a certified HAC installer in your area.


Do mini splits use a lot of electricity?

Mini splits use less electricity compared to traditional HVAC systems. The amount of electricity used depends on factors like the size of the system, the number of zones, and usage patterns. On average, a single-zone mini split uses 500-700 watts per hour.

What is the average cost to install a ductless mini split?

On average, single-zone mini splits cost between $3,000 to $4,000. The cost goes up with each additional air handler. Whole-home systems go up to $20,000. Federal incentives and utility company rebates reduce that cost.   

How long do ductless systems last?

On average, a mini split heat pump system lasts up to 20 years if the units get proper maintenance from an HVAC professional.

Find the best mini split installation company for your home in Cherry Hill, NJ or anywhere in New Jersey, Delaware, Maryland, or Pennsylvania.