As spring rolls into summer, many Massachusetts homeowners consider upgrading their home’s cooling systems in order to be prepared for the hot and humid months ahead. With the surge in popularity of ductless systems, many people wonder if a mini-split would be a good solution for them.

Unlike conventional ducted AC systems, mini-split systems consist of an outdoor unit and one or more indoor air handlers. These indoor air handlers serve the functions of a cooling fan, thermostat, and air purifier. Although a mini-split system is capable of cooling an entire home, the number of indoor air handlers required escalates proportionally with the size and shape of the area to be cooled. A mini-split system can accommodate up to eight indoor air handlers per outdoor unit.


Determining the cooling capacity of a mini-split air conditioning or heating system rests upon several factors, including the unit’s dimensions, the rooms’ insulation, the preferred temperature settings, and the local climate. It is best to consult an HVAC professional to ensure all necessary factors are taken into consideration before a system is installed. Nevertheless, one can conduct some preliminary calculations.

HVAC professionals can properly size and install the right ductless mini split for your home or space.

HVAC professionals often divide the area into zones rather than individual rooms when they are evaluating the best way to heat or cool a residential space. A single-zone mini-split AC is typically engineered to cool a single room, such as a bedroom or living room. Circumstances may occasionally allow the cooling of a more substantial area, denoted as a zone, encompassing a primary room and surrounding areas such as a bathroom or a laundry room. Multi-zone mini-split AC systems possess the capacity to regulate the temperatures of multiple rooms or zones by harnessing a solitary outdoor unit connected to several indoor units. The number of rooms or zones a multi-zone system can proficiently cool is contingent upon the system’s capacity and the number of indoor units installed.


Selecting an indoor unit for each zone depends on the number of BTUs (British Thermal Units) necessary to cool the space efficiently. BTU is a measurement unit that quantifies the energy an air conditioner expends to extract warm air from a home. Knowing the required BTUs per zone to cool your space will help in calculating the number of indoor units needed.

Indoor air handlers commonly generate cooling outputs spanning from 9,000 to 36,000 BTUs. Based on the stipulated BTU requirements, an HVAC technician can offer guidance in selecting a suitable air handler for a specific zone. However, a general guideline suggests that approximately 20 BTUs are needed to cool one square foot of living space effectively.


You can also use the chart below to estimate the number of mini-split indoor air handlers you may need:


500 Sq Ft      1 Mini-Split

750 Sq Ft      1-2 Mini-Splits

1,000 Sq Ft   1-2 Mini-Splits

1,250 Sq Ft   1-3 Mini-Splits

1,500 Sq Ft   2-3 Mini-Splits

1,750 Sq Ft   3-4 Mini-Splits

2,000 Sq Ft   3-5 Mini-Splits

2,500 Sq Ft   4-5 Mini-Splits

3,000 Sq Ft   5-6 Mini-Splits


Keep in mind that these figures are rough approximations and may not be universally applicable to all spaces. An HVAC technician can take all of the necessary factors into consideration before recommending a ductless mini-split.


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If your question still needs answering or you’d like to schedule a consultation, contact the friendly team at Genove Oil & Air, and we’ll help you find the right solution for your home or business.


Whether you need home heating oil or Bioheat delivery, or installation and service of oil & natural gas systems for HVAC, heating, and cooling—call us at 781-893-9191 or email us.