Mini Split Heat Pumps and How the IRA Can Save You Money


If you’ve been thinking about investing in a mini split heat pump for your home, now’s the time to make the leap. 

The IRA (Inflation Reduction Act), passed in August, includes rebates and tax credits that make these energy-efficient heating and cooling systems more affordable than ever. Americans who’ve never been able to even consider these energy-efficient options due to the high installation cost can now reap the benefits.

What Is a Mini Split Heat Pump?

To understand what a ductless mini split heat pump is and how it works, you first need to understand the basics of traditional heat pumps. A heat pump is essentially just a machine that can move heat from one place to another. Because it’s moving heat from one place to another instead of creating heat, heat pumps tend to use less energy than resistance heating methods like baseboards.

How a Basic Heat Pump System Works

To cool a space, a heat pump collects the heat inside your home, moves it outside, and then releases it. It does this by piping in extremely cold refrigerant and blowing a fan over the coil. Because heat always moves toward cold, the heat in the room is attracted to that coil of cold refrigerant. As the heat moves towards the cold coil, the rest of the room cools. 

If you want to learn more details about the fascinating science behind how heat pumps work, This Old House has a great video on heat pumps that covers it well.

What’s the Difference Between a Heat Pump and a Mini Split Heat Pump?

In a traditional heat pump, cool air is piped into the room using air ducts. Mini splits are smaller systems that don’t use ducts, and they can be used to both heat and cool rooms (thanks to something called a reversing valve). 

While traditional heat pumps have to be connected via ducts, the mini split system contains multiple pieces connected via refrigerant coils and electrical cords. A single outdoor unit (also referred to as “the condenser” or “the compressor”) is connected to indoor units (often called “head units” or “air handlers”). The outdoor unit handles the overall job of collecting and releasing heat outside, while the indoor unit controls the exact temperature and captures and releases heat inside. That’s why for a mini split system, you need an indoor unit for every room.

Vox made an interesting overview of mini splits and why they’re so revolutionary in the world of energy management.

Pros and Cons of a Mini Split Heat Pump

Overall, mini splits are a great option for many people. But they’re not the answer for everyone. As with any other heating or cooling system, there are pros and cons, though, for many people, the pros heavily outweigh the cons.


  • The outdoor part of these systems is smaller.

  • Heat pumps are often more energy-efficient than other types, like resistance heating. Because heat pumps are only moving heat from one place to another, rather than creating heat (like with a baseboard heater), they tend to be highly energy-efficient options that can lower power bills.

  • Not using ducts to move the air from the outside unit to the inside of your home increases the energy efficiency for mini splits — HVAC systemductwork is expensive to install and wastes energy. According to the U.S. Department of Energy, air traveling over ducts can lose 30% or more of its energy before it even gets to you. Ductless systems don’t experience that energy loss and, therefore, are more energy efficient than traditional heat pumps.

  • Mini splits allow more options for installation: You can put the head unit on the ceiling, on the floor, wall-mounted near the ceiling, or wall-mounted near the floor.

  • Temperatures in each room are individually controlled by the head unit (via remote control or app), so you don’t have to pay for heating or cooling rooms you’re not using.

  • Mini splits operate better in colder climates than traditional heat pumps — the old heat pumps tend not to work well as soon as temperatures dip below freezing or above about 100 degrees Fahrenheit.

  • Rebates and tax credits lower the upfront cost for homeowners.


  • Ductless mini split systems need frequent maintenance to keep energy efficiency at top performance — filters often need to be cleaned monthly, and you may even need an annual professional inspection to check for refrigerant leaks, cracks in the wires, or other potential issues.

  • Many mini splits still aren’t as effective in extremely hot or cold weather as non-heat pump systems (like electric forced air or baseboards). They’re better than traditional heat pumps, but still have an optimal temperature range and won’t work well outside that range.

  • Unlike duct systems, mini splits require an appliance installed in every room you want to heat and cool. And while they’re not huge, they’re more noticeable than a vent.

How to Size a Mini Split Heat Pump

Once you’ve decided that a mini split heat pump is the right choice for you, it’s time to figure out the ideal size of your heat pump.


To measure the product’s ability to heat and cool a space, check the BTUs (or British Thermal Units). Calculating how many BTUs you need for a space is relatively easy. Take the square footage of the entire space you want to heat and cool (like your home) and multiply it by 25. 

So, if you’re looking to cool five rooms that are all about 200 square feet, that would equal about 1,000 square feet. 1,000 x 25 = 25,000. So you would need a mini split system rated at about 25,000 BTUs that comes with five head units (one for each room you want to cool or heat). 

Now that calculation is based on the assumption that your home is well insulated. If your home is not well insulated (which is most common in warmer climates) or you want a mini-split system in a non-insulated space (like your garage), you’ll need to double your BTUs for the same results.


You might come into a situation where you see the system rated in “tonnage.” It’s not as common as BTUs, but thankfully, it’s an easy conversion between the two. Every ton is equal to about 12,000 BTUs, so if you’re looking for a 25,000 BTU heat pump (like the example above) and the systems are rated in tons, you know you’ll need a 2-ton heat pump. 

You’ll notice in this situation, we recommend something that’s a little below our ideal BTUs. That’s okay. These numbers are approximate, so look for the closest match to your needs, and don’t worry too much about the numbers matching up exactly if what you find is a little over or under your ideal rating.

Determining the Energy Efficiency of Mini Split Heat Pumps


You’ll also notice there’s a SEER (Seasonal Energy Efficiency Ratio) rating on heat pumps. The SEER rating was created to show the energy efficiency of cooling appliances like heat pumps. It’s a simple calculation rating the kilowatts per hour the appliance requires to run under “normal” use. 

Typical air conditioners tend to hover around 15 SEER, while ductless mini split air conditioners are usually higher, with a rating of 20 and up. But that’s only rating the ability of the appliance to cool a space.

HSPF (Heating Seasonal Performance Factor)

To determine the energy efficiency of the heating ability, you need to look at the HSPF. You may already be familiar with this rating system because it’s used for other heat-generating appliances, like water heaters. 

HSPF measures how many BTUs the appliance brings into your home per kilowatt hour. The U.S. Department of Energy sets the minimum HSPF a heating device can generate. In 2023, it’s being raised once again from 8.2 to 8.8. The higher the HSPF rating, the lower your energy bills will be.

COP (Coefficient of Performance)

There is one more way heat pumps are rated, and that’s the COP. The COP rates heat just like HSPF. They’re just different ways to calculate how well the appliance can heat a space. 

Often heat pump manufacturers display both the HSPF and COP to prevent confusion, but if you need to do the actual conversion, it’s simple enough. To get the COP of a device, multiply the HSPF by 0.293. 

So for a heat pump with an HSPF rating of 8.8, the COP rating would be 2.5784.

If all of these rating systems seem overwhelming, just look for a square that says “Energy Star.” Energy Star is an energy efficiency rating system created by the U.S. government that does all the calculations for you and offers a simple annual cost estimate based on energy usage.

How the Inflation Reduction Act (IRA) Can Save You Money

The passing of the IRA bill has created compelling incentives for American homeowners who make eco-friendly investments in their homes. That includes some insulated windows, roofs, and even mini split heat pumps. 

The enormous bill included a number of changes to tax credits. For the first time ever,mini split heat pumps are eligible for the Nonbusiness Energy Property Credit (NEPC). This old tax credit actually expired in 2021, but the IRA brought it back for 2022. If you haven’t yet claimed your $300 lifetime credit for heat pumps, you can do that until the end of the year.

In 2023, things are changing again, though. The NEPC will be replaced entirely with the Energy Efficiency Home Improvement Credit (EEHIC), a more generous version of the NEPC. 

Once the EEHIC is active, homeowners will be able to deduct 30% of a heat pump’s cost up to $2,000. And while the NEPC credit could only be claimed once, the EEHIC credit will be an annual credit through 2033. That means that you can claim the credit in 2023 and then make another applicable investment in the energy efficiency of your home in 2024 and get the credit all over again.

Learn More About the IRA

The IRA is a massive bill that will affect American homeowners in many different ways. Even those who don’t invest in energy-efficient upgrades will likely see a reduction in their energy costs.  

That’s because policy and regulation adjustments will play a part in the energy costs we all see over the next decade. The incentives in the IRA to reduce energy consumption are expected to drive down energy costs for everyone. This is great news considering energy costs are often a significant monthly expense that we can’t control as individuals. 

If you’re interested in learning more about the IRA and how it will affect you, read our in-depth guide.

by LastSale
by LastSale