How Many Square Feet Can a Mini Split Cool?

Many homeowners are opting for ductless mini split systems to heat and cool new builds and replace conventional HVAC equipment in existing homes. However, identifying the right size, type and model of mini split is key.

The square footage that a mini split can cool depends on the size, or amount of btu’s, of the mini split installed. The most common mini split installed is a 12,000 BTU unit– which can heat or cool up to about 550 square feet. Depending on the size of your home, you may need to install multiple mini split AC systems — perhaps of varying sizes — to adequately heat or cool the property. Generally mini split air handlers are offered in 12, 18, 24 and 36K options.

There are also multi-zone mini split systems that can connect two, three, or even up to four indoor zones to promote more whole-house climate control. These mini splits offer more total BTUs of cooling power and cover more space throughout the home. Multi-zone mini splits can have units installed on different levels of the property. All zones connect back to the outdoor condenser via wires and refrigerant lines — not ductwork like typical air conditioning. This makes them flexible and versatile when it comes to installation.

How many rooms your ductless mini split system can cool depends on whether you install a single-zone or a multi-zone model. Single-zone mini splits only have one indoor zone, which usually means they cool just one room. A multi-zone ductless system can connect up to four indoor zones, offering simultaneous multi-room cooling. Another factor to consider is how many BTUs the mini split is rated for.

One big advantage of mini split systems is that they offer customized cooling for each zone, using a hand held remote, something that comes in handy when a multi-zone system is installed.

Say you like cool air in the master bedroom, but your teenager likes a more moderate temperature. The zone in the master bedroom can be set to low, and the zone in the teen's room can be set to a higher temperature. This differs from the one-temperature-fits-all approach of conventional HVAC systems.

It really depends on how many square feet you're looking to cool. Here's an overview of a common mini split sizing chart and about how many BTUs you can need relative to square feet:

• 250 square feet: 6,000 BTUs
• 400 square feet: 9,000 BTUs
• 550 square feet: 12,000 BTUs
• 1,000 square feet: 24,000 BTUs
• 1,500 square feet: 30,000 BTUs
• 1,800 square feet: 36,000 BTUs

• A 500-square-foot home addition where it's either costly or not possible to extend ductwork would likely require a single-zone 12,000 BTU mini split.
• A 1,500-square-foot home would likely need a multi-zone mini split rated at 30-36,000  BTUs or higher. This situation would apply to both new construction homes or homeowners replacing an existing conventional air conditioner with a mini split.
• It's also possible to install a mini split in rooms that are either hard to heat or cool to complement a conventional HVAC system. Perhaps that space is a 700-square-foot four seasons room or a 1,000-square-foot basement. You'd want mini split units rated at 18,000 BTUs and 24,000 BTUs, respectively.

• Ceiling height and poor insulation: If you have ceilings that are higher than 8 feet, consider adding a mini split with 20% more BTUs. The same general rule of thumb goes for homes or rooms that are poorly insulated.
• Seasonal temperatures: If you live in a climate that regularly experiences seasonal temperatures of 90 degrees Fahrenheit or more, consider adding a mini split with 30% more BTUs after calculating your home's square footage.

For more information on mini split systems and how many square feet they can cool, contact HVACDirect.com today.