Considering upgrading your North Shore, Massachusetts or Seacoast, New Hampshire home’s heating and cooling system? Many local homeowners are turning to mini split heat pumps for improved efficiency and comfort. While often used for supplemental heating or cooling, the Kearney HVAC team often gets asked if mini splits can effectively cool an entire home. The short answer is yes, but there are several factors to consider.
Let’s dive into how mini splits work and what determines their cooling capacity for individual rooms and whole-home comfort.
Mini Splits 101: How They Work
Mini splits work the same way as central ducted heat pumps, by moving heat either in or out of your home. The only difference with mini splits, however, is that they can do so without the need for ductwork.
There are two main parts of a mini split system: an outdoor compressor and up to 8 indoor air handlers. A line of refrigerant connects the two, which transports heat between them depending on where it’s needed. In cooling mode, a mini split will remove the heat from your home working similarly to a traditional air conditioner. In heating mode, ductless heat pumps can effectively keep your home warm, without fossil fuel combustion, by extracting heat from the outside air to bring indoors—even in the below freezing temperatures we see throughout North Shore Massachusetts, and Southern New Hampshire.
Can One Mini Split Air Handler Cool an Entire Home?
Most homes require a multi-zone mini split system because a single indoor unit has limited capacity. Instead, multiple indoor air handlers are installed in strategically placed zones in your living spaces, each with custom controls. The combined power of a few of these units can efficiently replace a ducted furnace and AC system.
Why Proper Mini Split Sizing Matters
Regardless of the type of cooling system you have, proper sizing is essential for both energy efficiency and cooling performance. Having a unit that is either too big or too small can lead to numerous issues, like high energy bills, comfort issues, and premature breakdowns. Kearney HVAC takes HVAC sizing very seriously and follows industry best practices to ensure your mini split system meets the exact needs of your home.
The Role of BTUs in Mini Split Capacity
BTU, or British Thermal Unit, is a measure that refers to the amount of energy a unit uses to remove heat from your home’s air. One BTU is the amount of energy needed to raise the temperature of one pound of water by one degree Fahrenheit. For cooling, we typically look at how many BTUs a system can remove from a space per hour. The higher the BTU rating, the more powerful the cooling capacity. Several factors can contribute to your mini split heat pump system using more or less energy, including:
- Ceiling height
- Insulation quality
- Number & size of windows
- Local climate
- Home layout
Below is a rough guide to help you determine the number of BTUs a mini split will use to cool various spaces within your home. While this guide is a helpful starting point, every house is different and square footage isn’t the only factor to consider. The professionals at Kearney HVAC will size and install the perfect system for your home.
| Area Size | BTUs Per Hour Needed |
| 150 to 250 square feet | 6,000 BTUs |
| 250 to 300 square feet | 7,000 BTUs |
| 300 to 350 square feet | 8,000 BTUs |
| 350 to 400 square feet | 9,000 BTUs |
| 400 to 450 square feet | 10,000 BTUs |
| 450 to 550 square feet | 12,000 BTUs |
| 550 to 700 square feet | 14,000 BTUs |
| 700 to 1,000 square feet | 18,000 BTUs |
| 1,000 to 1,200 square feet | 21,000 BTUs |
| 1,200 to 1,400 square feet | 23,000 BTUs |
| Up to 1,500 square feet | 24,000 BTUs |
Expert Mini Split Installation & Industry-Leading Brands
At Kearney HVAC, we install industry-leading Mitsubishi Electric Ductless Heating & Air Conditioning Systems, which are unmatched in both quality and performance. As a local Mitsubishi Electric Diamond™ Dealer, our team has gone through extensive training on Mitsubishi Electric products and can even offer extended warranties on installation.
We’re also a qualified contractor in the Mass Save® Rebate Program, which offers homeowners up to $10,000 in rebates for mini split installations, and stay up-to-date on other incentives available in our service area. If you’re ready for a cooling system upgrade, contact our NATE-certified technicians today.
