When you finally come to that point when you need to select the system, it pulls you back to reflect on what you really need, which in the case of air conditioning purchase, generally means choosing the right type of system. If you’ve already been scouring around online or onsite for air conditioners, you must have discovered that there are many types of ACs out there. Of course, you wouldn’t miss the familiar window-type units; and there are the portable ones as well. But in recent years, most homeowners are usually torn between just two popular choices: central air conditioning system and ductless mini split system.

Which one is better? Which one is the right fit for your home? Which of these systems can give you the best comfort that you deserve and the money-savings that you need? To help you make the right decision whether to go for central AC or opt for the ductless system, this article gives you an insight about what are the things to look out for as points for comparison, what exactly these systems really are, how they work, and what are their advantages and disadvantages?

Before we set out exploring everything about central air and ductless mini split systems, it is important to consider the things that you need to be looking for in a system. Remember that an air conditioner is a major purchase and any misstep in your purchasing decision will have a huge impact on your comfort, convenience, and energy budget in the future. Knowing the general stuff that makes an AC system a good one, if not the best, will equip you with better understanding about what you really need, what you should be expecting, and why they are important.

Keep in mind that when it comes to finding the right air conditioning solution, there’s no such thing as one-system-fits-all. Everyone has varying needs and requirements, which make the matter of choice relative to a specific situation. Despite this, however, it can’t be argued that there are some common characteristics that make a system either stand out over the rest or pale in comparison.

To effectively compare your set of choices, such as between central air and ductless systems, here are three of the critical considerations:

A ductless mini split system refers to air-conditioning systems that are comprised of an outdoor unit called compressor and an indoor unit called air handler or the evaporator unit. This split design explains the name “mini split.” Aside from the electrical wire, a mini split has a piping component called a line set, which is normally penetrated to a small hole in the wall, connecting the outdoor unit to the indoor unit. As you’ll learn in the next section, this line set, which is composed of two copper pipes called a suction line and a liquid line (collectively referred to as refrigerant lines because they carry the refrigerant) plays an important role in how the system operates.

Essentially, a mini split system is compact. It is called ductless because it does not require ductwork, which is typical of the central air conditioning system. Remember that ductwork refers to those set of tubing that you would normally see being routed throughout different rooms in the house with an installed central air system. In its typical installation configuration, a ductless system shows the compressor placed outside while the air handler is mounted inside a specific room. This makes the heating and cooling specifically concentrated on a defined space or a particular room inside the house.

In many cases, one ductless system can have multiple air handlers installed in different rooms and connected to just one compressor. This is called temperature zoning because each air handler can be controlled independently, which means you can choose to set a different temperature for different rooms by simply controlling the specific air handler or indoor unit that is installed in each room. With this capability, a mini split system becomes an ideal solution for controlling temperatures for different rooms, which ultimately eliminates the usual issues on hot spots and cold spots that you normally experience with a ducted system.

A ductless mini split system is typically a reversible AC system. This means that it can cool or heat your room because it could both act as an air conditioning unit during summer and as a heat pump during winter. Basically, it can work either way depending on your desired mode of operation.

To understand how a ductless mini split system works, it is important to emphasize the process of heat transfer. This process of transferring heat is crucial in making the system work as an air conditioning unit and as a heat pump. The refrigerant, which is a liquid substance, that flows inside the refrigerant lines and throughout the system makes this possible. During the process, this refrigerant moves and follows a cyclic process, and always changing its state. It would either condense inside the compressor or evaporate inside the evaporator. Specifically, it absorbs heat inside the evaporator while in gas state and circulates it back in the condenser unit; when in liquid state, it releases the heat inside the condenser unit and then brings it back to the evaporator. This cycle simply repeats. In simple terms, it absorbs and releases heat.

Now, with this heat transfer thing that involves absorbing and releasing heat, the question is, how does the system cools or warm air to achieve the cooling or heating process? Here’s how it goes: As an air conditioner, the mini split system absorbs the warm air inside the room where the unit is installed, processes it into a cool air, and then circulates it back inside the room as a conditioned air through the air handling unit. As a heat pump, the system takes warm air from outside through the outdoor unit. This air is brought inside and eventually distributed throughout the room through the air handling unit and with the aid of the system’s fan system.

Central air conditioning system is one of the most commonly used comfort solutions in modern homes around the US. Unlike the mini split system, it consists of a duct network. Basically, it works to cool the entire house through the vents that are connected to the ductwork.

In its typical configuration, the central AC system is also a split system—consisting of an outdoor unit and an indoor unit. The outdoor unit is the condenser, which is usually a large metal box placed outside the house and responsible for taking the refrigerant gas that is transported from the compressor and converting it into liquid at a low temperature. Inside the condenser is the compressor that serves to compress low-pressure gas. The compressor consists of a condenser coil that helps release the heat from the refrigerant outside.

The indoor unit is the evaporator, which is typically inside the air-handler or installed on top of the gas furnace and inside the duct system. Placed inside the house, the evaporator is responsible for absorbing the heat inside your home and sending it to the refrigerant, and then outside the house. The evaporator unit consists of an evaporator coil that helps absorb the heat inside the house. Within the condenser and evaporator coils is the refrigerant which serves as the medium of refrigeration that helps absorb and releases heat. The refrigerant moves in a cyclic process throughout the outdoor and indoor unit and through the refrigerant piping system called line sets. The line set which are basically the copper tubing components that include the suction line (transports the refrigerant in its gaseous state, which is a cool gas) and the liquid line (transports the refrigerant in its liquid state, which is a warm liquid). The refrigerant constantly changes state—it condenses inside the compressor and evaporates inside the evaporator.

The other important components of the central air conditioning system are the electrical wire that’s used to connect the unit to the power supply, expansion valve that helps control the amount of the refrigerant that flows into the evaporator coil, the blower that helps circulate the air in the evaporator to allow it to be released inside the house, the fan system that helps blow air in the condenser to release the heat outside, the filter that screens out airborne contaminants, the thermostat that helps your regulate and control the amount of cool air that circulates inside the house, and of course the ductwork, which is used to let the air flow throughout the house and be distributed to each specific room through the air ducts. Together, these components work to provide centralized cooling or heating.

Basically, the central air conditioning system works by absorbing the heat indoors, cooling and dehumidifying it, and then blowing back a cool air inside the house. While this looks simple, there’s actually a whole lot of processes that take place inside the unit.

Here’s how the central air conditioning system works: After the air conditioning unit is turned on, the blower of your AC system sucks in the air inside your home through the intake vent of the evaporator unit and passes through the air filters. The filtered air reaches the evaporator coils. These are very cold coils because of the cold liquid refrigerant that runs through it. As a result, the air that arrives at the cold evaporator coils also gets cold. It’s a basic Physics principle that heat flows from warmer objects to cooler objects. The same thing applies here.

True to its nature, the heat naturally goes to the cold refrigerant. The refrigerant, in turn, absorbs the heat. This results with the liquid refrigerant evaporating into gas. Take note that this refrigerant in gaseous state, although vaporized, is just a little bit warm, and technically is still a cool refrigerant gas. The circulating refrigerant, which at this point, is a cool, low-pressure gas travels inside the suction line or the copper pipe of your unit that connects the evaporator outlet and the compressor inlet. The refrigerant in its gaseous state, which is basically the cool gas, is transported to the outside unit and reaches the compressor. The compressor pumps the refrigerant which is a saturated vapor. During this process, the molecules of the refrigerant is compressed. Remember that when molecules are compressed, its energy and temperature increases. This means that when the refrigerant gas is compressed at the compressor, it becomes a very hot gas. This results to the cool refrigerant gas turning into a superheated vapor.

The high-pressure refrigerant gas travels to the condenser coil which is also inside the outdoor unit. It is important to know that in the outdoor unit, there’s a fan that takes the air inside, passes it through the condenser coil, and blows it back outside of the unit. Basically, this fan helps dissipate the heat inside by blowing air. Now, when the hot outdoor air that is pulled by the fan passes through the hotter coil where the superheated refrigerant gas is also present, it forces the heat to flow out of the refrigerant and be dissipated outside. The refrigerant, as a result condenses into liquid. Although this liquid refrigerant is cooling off, it is still hot.

This warm air will eventually leave the condenser through the liquid line or the smaller copper pipe that connects the condenser to the expansion valve. The warm liquid refrigerant flows through the evaporator unit. Inside the evaporator unit, the temperature of the liquid refrigerant drops and then it evaporates into gas. As it happens, while heat is released outside into the atmosphere by the condensing coil, the evaporator coil releases the cool air inside your home through the ductwork. The fan system near the evaporator helps blow the air inside your house and circulate it into different rooms through the vents. Take note that while the heat is released outside and the cool air is distributed indoors, the heat inside the house is also absorbed at the same time to repeat the cycle.

While it is a proven system, centralized air conditioning systems are not perfect. In fact, most of the newer comfort solutions today are marketed as a better alternative to the centralized AC solution. These usual disadvantages or drawbacks to using the system are the following:

• Costly and complex ductwork installation:  Centralized air conditioning systems require the installation of complex ductwork which has to be routed throughout the different parts of your house. Aside from the intricacies involved in the application, the installation cost would be substantial, especially if you have a large house that needs to be centrally air conditioned.

• Hot and cold spots:  Having parts of your house extremely cold while the other rooms remain relatively warm is one the biggest issue with centralized air conditioning system. Essentially, this pertains to concern on temperature inconsistencies inside the house because the centralized AC system is either not properly sized, has poor insulation, or the ductwork has damage and leaks.

• Higher energy costs:  Centralized air conditioning systems are mostly energy-hogs because they require greater use of energy to properly operate and condition the air inside the entire home. Inefficient use of energy is also very common with the system. Due to its single, centralized control, it cannot regulate the temperature for specific rooms. Instead, it will have to cool the whole house even if the other parts of the house are not being used.

• High-maintenance costs:  Centralized air conditioning systems are usually prone to damages, which often calls for costly repairs or replacement of specific components. A simple leak in the duct, for instance, will already have a huge impact in the overall performance of the system. Proper maintenance of a centralized air conditioning system will usually require help from an HVAC professional, which is not cheap.

• Not flexible:  Being duct-based, a centralized air conditioning system will prove to be too limited as a system especially when you need to cool a specific part of the house that is not connected to the duct network. This issue usually crops up when one wants to cool a room addition, for example, but finds it impossible or impractical because the ductwork can’t be extended any longer without doing a costly and complex structural changes.

Between a mini split system and a centralized air conditioning system, there are so many stark differences. But when compared, it’s hard to determine which one is better and even harder to ascertain why one should be selected over the other.

In reality, there’s no way to determine which one is best to choose because situations differ for every household. So, when choosing the best air conditioning system for your home, it is imperative that you weigh you options well and consider all the advantages and disadvantages of your choices. When selecting between a mini split system and a centralized air conditioning system, pay heed to the most important considerations that matter to you and best applies to your particular comfort needs, budget, and situation.