Are Mini-Splits Just as Good as Central Air?
There are many types of air conditioners but central air (split-systems) and ductless mini-splits air conditioners are the 2 most common ones for residential applications in North America.
While central air conditioners have been the air conditioners of choice for most homeowners for many years, ductless mini-split air conditioners are also gaining popularity due to some of their advantages over central air as we will see in this post.
The main difference between central air and ductless mini-splits is that central ACs have one indoor unit and provides consistent cooling/heating throughout the entire house using air ducts, while ductless mini-splits have not ductwork but a single or several indoor units, allowing built-in temperature zoning.
In short, central air uses ducts to supply consistent air/heat to the entire house from a single indoor evaporator coil. Ductless mini-splits can have one or several evaporator coils connected to one outside unit to cool/heat specific rooms hence doesn’t need ducts.
Ductless mini-splits are just as good as central air conditioners. They allow you to set the temperature of each room/zone different from the other, they are easy to install/maintain and importantly they are more energy-efficient. Mini-splits are expensive to install but cheaper to run.
Ductless mini-splits are cheaper to run than central air systems. While central air conditioners are always cooling the entire house, ductless air conditioners only cool the space being occupied which helps to save on energy. In most central air systems, 30% of air is lost to leaks in ducts hence low efficiency.
Both central and ductless mini-splits ACs are good choices so it depends on the homeowner. Mini-splits are efficient, allow integrated zoning but have higher initial costs. Central air offers consistent cooling to the whole house, low initial cost, better at eliminating humidity and cleaning the air but energy-inefficient.
The cost of installing ductless mini-split ACs is about 30% higher compared to central air ACs assuming you already have the ductwork in place. However, when both are being installed in new houses (no ducts), ductless mini-splits are cheaper to install.
You do not need a ductless mini-split unit in each room. Only the room you need to air condition. However, if you need to cool/heat all the rooms in your house, you need an indoor unit for each room, but connected to one outdoor unit. One evaporator coil cannot cool the whole house.
Thanks to the inverter technology incorporated in minis-split air conditioners, they are more energy-efficient than central air conditioners. With the inverter technology, you can save up to 58% in power consumption.
Mini-splits do not only cool a house but they can also heat it. Mini-split systems with heat pumps guarantees zone-to-zone cooling during the hot months of summer as well as heating throughout the cold months of winter.
Pros and Cons of Ductless Mini-Splits
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Pros and Cons of Central Air ACs
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Central Air Vs Ductless Mini-Splits Air Conditioning Systems
Both central air conditioners and ductless mini-splits air conditioners use the same principle to work. They both have indoor and outdoor units, connected together using copper tubes to form a closed loop.
The outdoor unit comprises of the compressor and the condenser coil while the indoor unit is the evaporator coil. A refrigerant is circulated between these components where it changes from liquid to gas and back to its liquid state.
With each change of state, the refrigerant is either absorbing or releasing heat. Freon has been used for many years but as of now new ACs are using R-410A. More on that in this post.
Inside the house, the refrigerant enters the evaporator coil in its liquid state, meaning that it is very cold.
If you have a central air system, a thermostat which is usually centrally located signals the AC components to start running when the air starts to heat up.
The evaporator coil impeller fan pulls the hot air from the house using return air ducts and forces it through the evaporator coils. The refrigerant absorbs the heat from the air which is then sent back to your house via supply ducts.
With ductless mini-splits, the evaporator coil is installed in the room it is supposed to cool hence there are no ducts needed. The fan pulls hot air from the house and then releases it back after passing it through the evaporator coils.
After absorbing heat from the hot indoor air, the refrigerant evaporates and is sent back to the compressor where it is compressed before being sent to the condenser coil to dissipate the heat to the surrounding and hence condenses back to its liquid state.
The cycle goes on and on until the house/room is properly cooled.
Let us now look at the advantages and disadvantages of both central air and mini-splits air conditioners in more details.
Advantages/Pros of Ductless Mini-Splits Air Conditioners
Initially, mini-splits were used to provide cooling in individual rooms like garages, patios, basements, home offices or other additions. Today they are also used to cool/heat entire residential units.
The following are the advantages of mini-split AC systems:
1. Temperature Control of Each Room
One of the things I love the most about ductless mini-splits AC systems is that you don’t have to have the entire house set at one temperature. Each room/space can have its separate temperature setting allowing for built-in zoning.
Minis-splits are controlled using a remote control and each indoor unit (for every room) has one. If you therefore want to have your home gym or office unit set at a lower temperature setting than the bedroom then you can do just that.
Mini-splits can also be converted into smart air conditioners where you can remotely control the temperature of each room using your smartphone. You can do so much with your phone including geofencing, receiving usage data as well as scheduling in accordance with weather forecast.
2. High Energy Efficiency
Did you know that almost 30% of the conditioned air in ducted systems is lost through leaks in the ducts? Now you know!
Since mini-splits don’t utilize ducts, there is no loss of conditioned air which means their efficiency is quite high. All the cooled or heated air is dissipated throughout the room where it is needed.
Mini-splits also use variable-speed compressors which can be adjusted to precisely run as fast or as slow as needed. That allows maximum utilization of energy, unlike the case with most central systems whose compressors have 1 or 2 speeds and therefore needs to keep turning on and off.
Ductless mini-split AC systems also use AC inverter technology which converts energy from high voltage alternating current to low voltage direct current hence saving energy.
As a matter of fact, the inverter technology allows these units to save up to 56% in energy consumption. That will be reflected in your bills
3. Low Running Costs
The cost of running a mini-split system is lower compared to central air conditioning systems. Modern central air systems are more effective than old ones but are still no match for mini-splits.
To start with, mini-splits are more energy-efficient than central air systems and don’t lose air to leaks. The energy bills for mini-splits will therefore be lower than central air.
The extensive ductwork in central air will need to be regularly maintained by HVAC technicians, which is also not cheap. Mini-splits repairs are cheap which means you save money in the long run.
4. Easy Installation
As you would imagine, it is way easy to install minis-split systems compared to central air systems. With mini-splits, you only need to drill a small hole through the wall to connect the indoor unit to the outdoor unit and you are done.
That is however not the case with central air. A route for installing return and supply air ducts has to be designed and implemented by an HVAC professional. The installation process is also quite invasive and takes a long time.
5. Not Noisy
Unless your ductless mini-split air conditioner is faulty, it is not supposed to be noisy. These units’ fans run at a slow speed which doesn’t bother you as you go about your business.
That however is not always the case with central air systems. The air ducts used to supply air to the house causes vibrations as air moves within them hence creating noise. Although that is usually not a problem for most folks, it is less than ideal to some.
If you therefore want to install a quiet air conditioning system then mini-splits should be the ones to go with.
Ductless mini-split AC systems are so versatile. You can get them in big or small sizes as well as in different forms of installation.
If you only want to cool a single room, you can get a small outdoor unit and a small indoor unit as well, lowering your purchase and installation cost.
You can also get a big outdoor unit which you can connect to several indoor units if you want to install a minis-split system for your entire house.
If your house has a high ceiling, a wall-mounted mini-split indoor will work well for you. It is also very easy to install.
The indoor unit can also be suspended from the ceiling but if you don’t like it being too conspicuous you can opt for a cassette/ceiling-recessed unit.
If you have delicate walls or ceilings, a floor-mounted air conditioner will come in handy. It is also great for seniors who need to easily replace the air filter.
7. Perfect for ADUs/Additions
As mentioned earlier, mini-splits are perfect for cooling/heating individual units. Central air would not be cost-effective in that case.
Even if you have a ducted AC system then decide to add an accessory dwelling unit (ADU) or any other addition, a mini-split will be a perfect solution for your cooling and heating needs unless you want to try window or portable air conditioners.
Disadvantages/Cons of Ductless Mini-Split AC Systems
Even with their many benefits, minis-splits are not without fault. The following are the disadvantages of mini-split systems:
1. High Initial Cost
The initial cost of installing ductless mini-split AC systems is about 30% higher than that of installing central air conditioners. This is especially the case when installing several indoor units (one for each room in your house).
The statement above however only holds water assuming that the house where the central air conditioner is being installed in has existing ductwork (as is usually the case). If the installation is in a new house without ducts, installing central air ACs will be more expensive.
It is however impossible to give a concrete figure when talking about the cost of installing air conditioners as it depends on so many factors like size of the house, climatic conditions of your area, brand, labor charges etc.
According to Home Advisor, the cost of installing a central air conditioner is between $1900 and $4200 while that of installing a mini-split AC system is between $2000 and $14500.
2. Not Appealing to Look at
For mini-split air conditioners to effectively condition the air in your room, they need to be located in an area of the room where air will be evenly distributed. That is why the wall or the ceiling is the best place to install them.
Unfortunately, these units are not pieces of art. They are not pleasant to look at and I know several people who opted not to install them on that basis.
Because the walls in most houses are painted white, manufactures also manufacture them in white to try and blend in but they are still quite conspicuous.
Although they take time and are a little expensive to install, you can opt for ceiling-recessed mini-split units if the wall-mounted ones bother you.
Floor-mounted units are not as conspicuous as wall-mounted units but air flow can be hindered by furniture and other objects, probably the reason wall-mounted mini-splits are the most popular type.
3. Ineffective Air Filtration
Although ductless mini-splits have air filters in their indoor units, they are not nearly as effective in cleaning the air as those in central air AC systems.
Mini-splits unlike ducted ACs also do not bring fresh air from the outside but instead cool the air already inside the room. As such, you may be required to consider air purification which needless to say will be an extra cost.
4. Unsuitable for Large Areas
Ideally, mini-splits are perfect for individual small areas but not whole residential units. That is why most homes in the United States use central air conditioners.
Attempting to cool an entire house with a single mini-split unit will not work as that will result in undercooling as well as premature failure of the AC components (especially the compressor) due to overheating.
That is however not to say that mini-splits cannot work for large residential units. They will work just fine but you need to install several indoor units and a properly sized outdoor unit to handle all the cooling and heating needs.
Advantages/Pros of Central Air Systems
It is not by mistake that central air systems are the most common AC systems in North America. They are work great and are very practical.
The following are the advantages of central air conditioners:
1. Perfect for Large Areas
If you want to install an air conditioner in a residential unit, a central air conditioner is a great choice. It will cool/heat every corner of your house without being overwhelmed since it will be properly sized from the beginning.
Central air systems have a big outdoor unit and an indoor evaporator coil which works flawless circulating cool air throughout a house no matter its size.
2. Low Initial Cost
As I had mentioned earlier, the initial cost of installing a central air conditioning system is about 70% that of a mini-split system. Again, that is assuming there are already air ducts in place.
Just to remind you that the cost comparison is not usually very accurate as it will depend on several factors which will vary from person to person and from area to area.
3. Perfect for Air Purification
Central air unlike mini-splits is not only good in cooling your house but also removing humidity and cleaning the air thereby removing all the pollens, dust, lint and other dirt suspended in the air.
In central air conditioning systems, the evaporator coil pulls air to the evaporate through the return air ducts. Before getting to the coil, the air is first passed through an air filter where dirt, lint and other impurities are filtered out.
The supply air ducts will then supply all the areas with cooled and purified air, meaning you will not need to invest in air purification.
4. Not an Eyesore
Central air conditioners do not interfere with your interior décor in any way. The evaporator coil is placed away in a central location but importantly where you do see it all the time. You walls, ceilings and floors are therefore free for you to decorate them (or leave them as they are).
The only thing that that you may not like are the giant outdoor units but you can always find unique ways to accessorize the area making them not to be the center of attention.
Disadvantages/Cons of Central Air Conditioners
Just like mini-splits, central air conditioners also have their limitations. It’s upon the homeowner to choose the system with the least inconveniencing disadvantages.
The following are the disadvantages of central air conditioners
2. High Running Costs
If your central air conditioner will be losing up to 30% or more of the conditioned air, it means it will need to work harder to satisfy your cooling/heating needs. That will definitely be reflected in your energy bills.
As Mentioned earlier, central AC systems cool/heat all the rooms in the house at all times unlike mini-splits which makes them very energy-efficient. The overall cost of running central air conditioners is therefore higher than mini-splits.
3. Air ducts Need Maintenance
With central air conditioners, you will need to bring over an HVAC technician regularly to inspect and do maintenance on the ducts. That include cleaning and sealing leaks. It goes without saying that these services are not cheap.
Such can be avoided by installing mini-splits which as we know have no ducts. Failure to have the ducts properly maintained will result in air loss to leaks and also ineffective cooling due to blockages.
4. High Cost of Installing from Scratch
Installing central air conditioners from scratch (in a newly constructed house or one that didn’t have ducts before) is very expensive.
For perspective, the cost of installing air ducts is $4000 (national average) but the cost can be as low as $1900 or as high as $6000. That is definitely not pocket change.
When that is the case, the cost of installing a ductless AC system will be considerably lower.
5. No Built-In Temperature Zoning
Unlike mini-splits, central air does not offer in-built temperature zoning. All the rooms in the house are cooled/heated at the same temperature.
While that is not a big deal, I am sure there are people who really like the option of being able to have varying air temperatures in different areas of the house.
Conclusion: Which is Better Between Mini-Splits and Central Air?
As we have seen from the above posts, both ductless minis-splits and central air conditioners have their advantages and disadvantages. Although central air have always been the preferred types of ACs through, it is not hard to see why mini-splits are gaining in popularlity.
I would say that if your house has goo air ducts (that are not leaking) and you really don’t care much about the integrated zoning offered by minis-splits, central air will be a good option for you.
On the other hand, if you have a new house that you need to install air conditioning or you are particularly very specific about the temperature of each room, mini-splits should be your air conditioners of choice.
As I mentioned, modern central air conditioners are more energy-efficient than the older types but mini-splits are still better at energy consumption (saving energy). Again, this is a reason for you to consider mini-splits over central air.
You can also go ahead and consult a local HVAC technician on the best type of AC to install based on your needs, location, budget among other factors.
All in all I hope you enjoyed reading this post.