A mini-split unit is an efficient way for you to heat and cool your home in Plainfield, IL. At TR Miller Heating, Cooling, & Plumbing, we want to ensure that our customers have all the knowledge that they need when choosing one of these systems for the first time. Below, we will explore how a mini-split system works so that you can make the best decision for your home.

The Basics

A ductless mini-split has a heat pump that pumps the heat within your home outdoors in order to cool. It does the opposite to heat your home. Mini-splits are energy efficient because they don’t actually create heat the way a furnace that burns gas does. The mini-split unit simply transports heat from point A to point B. The system works with a refrigerant cycle. This thermodynamic cycle relies on the expansion and compression of refrigerants to transport that heat.

A mini-split consists of three main components:

  • An outdoor unit
  • An indoor unit
  • Refrigeration lines

The outdoor unit is where the compressor is found. It is usually placed on a cement pad or raised up off the ground, and it can be placed in an inconspicuous location. The indoor unit is an air handler that mounts on the wall. It is small, sleek, and unnoticeable in most situations. It won’t interfere with your home’s existing decor the way that many other heating and cooling options will.

You should know that a mini-split system may have multiple indoor units. You could have several within one house, depending on the model that you purchase and your individual needs. This allows you to set each room’s temperature individually. During the winter, you can keep rooms like the guest bedroom cooler and then focus on keeping the main living areas where you spend the most time warmer. The refrigerant lines connect the inside units with the outdoor unit.

The Cooling Process

The compressed refrigerant is in a liquid form at low pressure. It will flow from the outdoor unit to your indoor unit by traveling through the refrigeration lines. When this liquid reaches the evaporator cooling coils found in the indoor air handler, it will expand and turn into a gas. This is an endothermic process that cools the coils.

The indoor air blower pulls your home’s warm air in and pushes it across these coils. The coils cool that air while removing the humidity from it. The now cool and dry air is blown into your home. You will feel this as the cold air blows out of the indoor air handler unit. The now high-pressure gaseous refrigerant then travels back to the outdoor unit through the refrigeration lines. That refrigerant is compressed in the outdoor unit and is turned back into a liquid. This exothermic process generates heat, and that’s why the outdoor unit will feel hot.

Now that the refrigerant has been turned back into a liquid, it will travel back inside to the indoor unit through the refrigerant lines. It will now repeat the entire cycle. This cycle repeats until the air inside your home reaches the desired temperature.

The Heating Process

You would typically think that you need a furnace to heat your home and an air conditioner to cool it, but the mini-split does both. It heats by reversing the cooling process. The mini-split has a switch called a reverse valve that changes the direction of the refrigerant’s flow. Instead of cooling your home, it now heats it.

When the mini-split is acting as an air conditioner, the refrigerant is expanded inside. This provides cool air for your home. It’s compressed outside, where it gets rid of the heat. Once the reverse valve is switched, the mini-split’s heat pump gathers up all of the outdoor heat and carries it inside. This is possible because the compressor has the ability to work as an evaporator that expands the refrigerant gas.

The compressor expands the liquid refrigerant into a gaseous refrigerant. That refrigerant is now hot. That hot refrigerant is sent inside, where it goes through the indoor coils and warms them. Air is blown over the now hot coils and expells that warm air into the home. At this point, the hot gas is cooled and turned back into a liquid. This liquid travels through the refrigerant lines to the outdoor unit once more. A compressor will expand the liquid into a hot gaseous refrigerant, which completes the heat cycle. Just like when cooling your home, this cycle will repeat until the air inside of the house reaches your desired temperature.

How the Mini-Split Controls the Temperature in Your Home

Mini-splits have an internal thermostat that detects the temperature in a room and tells the system whether or not to start cycling. You won’t have the traditional wall-mounted thermostat that you see with a furnace. Instead, you’ll have an LED remote that allows you to control the mini-split settings. You must be near the mini-split system in order for the remote to work.

Many homeowners decide to get a smart thermostat for their mini-split system. This allows you to set your home’s temperature from remote locations by using your mobile phone. You will be able to create a schedule for heating and cooling your rooms and track when it’s running.

A System That’s Suitable for Many Applications

Mini-split systems are relatively easy to install, and they typically require nothing more than a small three-inch hole through the wall. This hole is used for the conduit that holds the refrigerant lines. A mini-split is an excellent way to heat and cool new construction, but it provides people that own older houses without ductwork an energy-efficient option for keeping their home comfortable. They’re also great for new additions where extending the ductwork isn’t possible.

Rely on the Mini-Split Professionals

If you are considering a mini-split unit for your home, TR Miller Heating, Cooling, Plumbing & Electrical is ready to assist you. We’ll answer all of the questions that you may still have about a mini-split. We can also provide you with a variety of other valuable services to enhance your home’s comfort. We offer heating and air conditioning installation, repair, and maintenance, and we handle water heater services, gas line repairs, sump pump services along with a wide array of other plumbing services. Be sure to ask about our service membership and financing options.

Our company is proud to be a family-owned, third-generation business that has been serving Plainfield and the surrounding Chicago suburbs since 2008. Our certified technicians use the latest technology and ongoing training to provide you with excellent customer care and straightforward pricing. Our goal is to ensure you receive the fast and reliable services you need to keep your home comfortable all year long. Call TR Miller Heating, Cooling, Plumbing & Electrical today to learn more about all of your heating and air conditioning options.

Author

  • brian sloan headshot

    Brian Sloan is the President of TR Miller Heating, Cooling, Plumbing & Electrical, one of the western Chicago suburbs' leading family owned home service companies, serving homeowners across more than 80 communities throughout Will, Kendall, DuPage, Kane, and Cook counties.

    TR Miller is more than a business to Brian, it's a family legacy. The company was founded by his father, Tim Miller, and Brian and his brother Jim have played an important role in growing the business from a small local operation into a full service residential HVAC, plumbing, and electrical company serving homeowners throughout the greater Chicagoland area.

    Brian's perspective on the home services industry comes from firsthand experience. Before taking on leadership responsibilities, he worked in the field as an HVAC Service Technician and Fabrication Technician, diagnosing heating and cooling systems, assembling custom HVAC components, and supporting residential installations throughout the western suburbs.

    That hands on foundation continues to influence the way Brian leads TR Miller today. He understands both the work taking place inside a customer's home and the systems, training, and support required behind the scenes to consistently deliver a great customer experience.

    Over the course of his career at TR Miller, Brian has worked across nearly every major area of the business, including operations, marketing, sales, job coordination, customer service, finance, and leadership. Today, as President, he is responsible for the overall strategy, growth, culture, and performance of the organization.

    That breadth of experience across both the technical and business sides of home services has helped shape how TR Miller operates: combining the systems and accountability of a professionally run organization with the care, responsiveness, and personal connection of a family business.
    Brian's philosophy is straightforward, make home services convenient and reliable while giving homeowners the information they need to make the best decisions for their homes and families. That means educating customers, providing clear options and upfront pricing, and making sure homeowners understand both what was found and why a repair or replacement may be recommended.

    Under Brian's leadership, TR Miller has expanded beyond HVAC into plumbing and electrical services, grown across multiple locations, invested heavily in technical and leadership development, and been recognized seven times on the Inc. 5000 list of America's fastest growing privately held companies.

    Credentials & Affiliations:
    - President, TR Miller Heating, Cooling, Plumbing & Electrical
    - Membership Officer, YPO Chicagoland
    - Board Member, Nexstar Network
    - Former Vice Chair, Board of Directors, Plainfield Shorewood Area Chamber of Commerce
    - Associate's Degree, Waubonsee Community College
    - Former HVAC Service Technician & Fabrication Technician, TR Miller

company icon