The Difference Between Window Units vs Central Air Conditioners Explained

Carolina Evans
Carolina Evans
Research Writer
Holds a Master’s degree in Engineering and is keen on her own home’s climate. Sometimes we think that Carolina owns every single product she writes about – that’s ho read more
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Richard Powell
Richard Powell
Expert Consultant
For 8 years, Richard had been working as an HVAC specialist and AC unit installer since his student years. Now, he’s our main consultant on every technical aspect that may read more
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To stay cool all summer long, there’s nothing better than an air conditioner! But between a central air conditioner and a window-mounted air conditioner, which one should you choose?

To answer this question, you will need to know the differences between both. All the types of air conditioning systems have a variety of their advantages and downsides. Among the various types available, window and central AC systems are very popular. In this window units vs central air comparison article, we will see how the two AC units work, their advantages and disadvantages, and see how they compare to each other.

In any case, before deciding on which will be the right choice for you and your home, take into consideration the space you would like to cool or heat and what will be the most important feature for you when it comes to air conditioning.

How does a window air conditioner work?

The Difference Between Window Units vs Central Air Conditioners Explained

Window units are air and heating conditioning systems which have all necessary components which central ACs have. But they are usually in portable boxes.

Window AC units are one of the most affordable options on the first purchase and the most optimals for small rooms or spaces.

The HVAC power of window systems are only suitable for small areas. For instance, the Frigidaire 5,000 BTU Window-Mounted Air Conditioner can only cool a space of 150 square feet. This means that to cool a whole home, each area will need its unit – one for the living room, one for the bedroom, another for the kitchen.

Window air conditioners work like other air conditioning systems. They suck in the warm room air, cool it down inside with the help of a special cooling circuit and a refrigerant, and blow the cooled air back into the room. The waste heat that is generated when the rooms are cooled is transported outside.

Most modern window air conditioners are equipped with innovative inverter technology. This means that the window air conditioner continuously determines the temperature of the air drawn in using a thermostat.

If this exceeds the value you entered, the refrigeration unit switches on automatically. If the room temperature becomes too low, the refrigeration unit switches itself off again. The performance of the compressor adapts continuously to the cooling requirement. The desired room temperature is kept constant.

  • The inside unit: The warm air is sucked in at the front of the air conditioner. This faces the room and is almost flush with the room wall. The warm room air enters the window air conditioning system through a grille with an air filter and goes through the cooling process here. The cold air is then released back into the room through mostly manually adjustable slats. These are also located on the front of the device. The power connection and the control panel are also located on this side of the device inside the house.
  • The outside unit: The window air conditioner has the shape of a cube or parallelepiped. The major part of the device protrudes from the window and is about 8 to 20 inches outwards. The warm exhaust air is transported outside through an air outlet. In contrast to a mobile air conditioner, no exhaust hose is required. This not only means huge space savings but also easier handling. The resulting condensate is also discharged outside.

According to most reviews, the MAW05M1BWT Window air conditioner, designed by Midea, is by far one of the most reliable and time-proven ones. It has 5,000 BTU capacity, Mechanical Controls, 7 temperatures, and 2 cooling and fan settings.

Pros of window air conditioners

The advantages of window air conditioning systems at a glance are

  • Efficiency: Thanks to modern inverter technology, the room temperature is constantly regulated. This will reduce power consumption.
  • Easy assembly: The indoor and outdoor units are in one device. However, the assembly must be carried out by a specialist company. The cost of assembly is however lower than that of a central air conditioner system.
  • No exhaust hose: There is no need to constantly use an exhaust hose. Also, the transition to the outside can be better sealed and the window remains closed during operation.
  • Versatile use: Whether in the window or a wall opening – the window air conditioner can also be easily installed afterwards. In the case of rental apartments, you need the approval of your landlord.
  • Multifunctionality: Many windows with integrated air conditioning have a fan and a dehumidifier function.
  • Inside look: Inside, the window air conditioners are installed almost flush with the wall. As a result, they are less noticeable and take up less space.
  • Price: On average, window air conditioners are considerably less expensive than central air conditioners in terms of acquisition costs and operating costs. Acquiring a central AC will cost you between $1500 to $10,000 but a window AC costs between $350 to $1,500. The monthly running costs of a window AC are between $30 to $80. However, the average cost of running a central AC is $115 Trusted Source How Much Does Central Air Cost? | Direct Energy Blog Many factors can affect how much your central air costs. Learn how to calculate the cost of your central AC and get tips on how to save money. , according to Direct Energy.

Cons of window air conditioners

Below is an overview of the disadvantages of window air conditioning systems:

  • Fixed installation: The window air conditioners are permanently installed in the window. Unlike central air conditioner systems, they only cool a certain room and have a lower cooling capacity.
  • Noisy: Since the compressor, evaporator, etc. are located in one housing, window air conditioners are significantly louder than central systems with indoor and outdoor modules. However, they tend to generate a little less operating noise than mobile monoblock devices.
  • Exterior appearance: The cuboid devices protrude a good bit out of the window.
  • Less light: When installed in the window, the air conditioning unit fills a considerable part of the window. This visually reduces the window size and less sunlight gets into the room.

How does a central air conditioner work?

The Difference Between Window Units vs Central Air Conditioners Explained

Central ACs are systems that work throughout the house through ducts. The outdoor or condenser unit is usually located outside the house. Ducts can be connect from the heater through the attic. Centralized units have an outdoor unit and an indoor unit. However, in this case, the indoor unit will distribute the air through ducts to the different areas of the home.

Central air units are the most efficient of all types of air conditioning systems. They are very popular among homeowners as they are efficient, convenient, and durable.

A central air unit works by removing heat from the service room and transferring it outside the building. In essence, the functional principle of a central air conditioning system does not differ significantly from the functional principle of other refrigeration devices.

The movement of the refrigerant, its transition from a gaseous state to a liquid, takes place via two nodes: an evaporator and a condenser. The indoor unit contains the evaporator assembly and the condenser is part of the external device.

The general scheme of operation of the unit during air cooling is based on the fact that the air from the room enters the indoor unit with the help of a ventilation grille and a diffuser. It is then processed accordingly and returned to the room, but it is already cooled to the desired temperature.

Considering the way the duct/central air-conditioning system works, the arrangement of the ventilation ducts makes it possible to distribute low-temperature air flows over a large area of ​​the property. The heat collected when the air cools is discharged into the street in the form of condensate.

Due to the properties of the device, duct-type air conditioning systems work on the principle of local air circulation, i.e. suction from the room and further processing of the air environment and the return of air that has already been cooled through the duct system.

There are inverter duct air conditioners with built-in capacity control, depending on the temperature of the air. The performance of such devices is higher, as are the possibilities.

By inversion of the alternating current in a direct and an inverse process, in which it becomes possible to achieve the required frequency of the alternating current, such duct devices save energy.

Pros of central air conditioners

Centralized units work like any other air conditioning system. It, therefore, has some interesting advantages over other air conditioning systems.

  • Reduction of energy costs: In addition to being a more aesthetic option, these air conditioning systems are capable of reducing energy consumption while the performance is higher. More throughput translates to a lower utility bill per month.
  • More uniform air conditioning: It is, without a doubt, another of the great advantages of centralized air conditioning. With these ducts, you will achieve more uniform air conditioning in the different rooms of the home. The reason is that this centralized system allows us to better distribute the air through different outlets, thus optimizing its performance compared to a single air outlet. If you have a window air conditioner, for example, you’ll need a higher power or a lower temperature to get to cool areas away from the machine. This does not happen with a centralized or ducted air conditioning unit. Instead, a single installation will cool the whole house.
  • Air zoning: Not all centralized air systems allow it, but usually they do and it is an important advantage. If you are not in a room, you will be able to close the circulation of cold air in it, through a remote control. This way, you will ensure that the power, and consequent expense, is focused only on where air conditioning is most needed for.
  • A silent solution: Central air conditioning systems are really quiet. Yes, it is true that today any independent machine is, but considering that you are air-conditioning the entire house, they are machines and ducts capable of operating so quietly, ensuring you have uninterrupted rest at all times at home.

Cons of central air conditioners

Are central air conditioning systems all about the advantages? No! But perhaps the disadvantages do not seem so many compared to the advantages.

  • Higher investment price: The acquisition and installation costs of the central air conditioning may be higher, in the long run, the energy-saving will compensate for them.
  • Installation: The installation of centralized air requires a lot of work. Yes, it is possible to place the ducts visibly, something that could look great in an industrial-style home. But if you opt for the false ceiling and the hidden ducts, there will be more installation work and it will be more expensive.

Window AC vs central AC: Side by side comparison

Below, we compare both types of air conditioning system, using criteria such as energy usage, ease of installation, performance, and cost

  Central AC Window AC
Energy usage Central ACs use 3.5 kilowatts on average


Window ACs use around 0.5 to 1.44 kilowatts on average
Ease of installation  Installation process could be easier and less expensive only if you have a functioning duct system. The overall installation process is simpler
Performance and efficiency Central air units are very high-performing and efficient, with uniform cooling. Window ACs are not as functioning as central ACs
Cost Acquisition and installation costs of central ACs are higher, but operation costs, in relation to the cooling efficiency, are lower. Acquisition, installation, and operating costs are lower

Final thoughts

Central air conditioning and window air conditioning systems work similarly. However, the centralized systems are more efficient than others but the purchase and installation costs may be higher, as we have seen in this window units vs central air conditioning comparison article.

The central air conditioning system is installed in the attic of your home and connected to an outdoor unit. The cooled air is distributed to the rooms of your house through a network of ducts. The interior temperature is uniform from one room to another. Meanwhile, the window-mounted air conditioning system which is made up of indoor wall units connected to an outdoor group can only cool the rooms they’re located in. The temperature of each room can therefore be adjusted as needed.


How Much Does Central Air Cost? | Direct Energy Blog
Many factors can affect how much your central air costs. Learn how to calculate the cost of your central AC and get tips on how to save money.
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