Central vs. Window AC: Complete Comparison

Heat waves and heavy hanging humidity can leave homeowners desperate to cool off, seeking refuge in that sweet, sweet AC. When you’re looking to cool off your own home, what’s the best, fastest, most efficient way to go about it? 

Window AC versus central AC: Which system cools your home best? Which system is the best bang for your buck? Which is more efficient and will keep your bills lower? As with so many aspects to consider in the debate, the frustrating answer is often “it depends.’

To get the cooling solution best for your home, you should understand the pros and cons of a window unit AC versus central air before you invest.

What is a Central Air Conditioner?

If you’re trying to decide between the two, it’s valuable to get a firm understanding of what each type of unit actually is and how it works.

Central air conditioning is often a favorite among homeowners since it can boost your home’s value and make it more attractive to buyers who benefit from reliable climate control, such as the elderly, people with allergies or parents with young kids.

Beyond just curb appeal, central air conditioners have really stepped up their efficiency game in recent years, which, when you’re directly comparing window AC versus central AC, is a huge advantage. With a wealth of smart thermostats available, zoning capabilities and ductless central AC systems, energy efficiency is definitely a priority for this industry.

Central air conditioners work using the ductwork in your home. They use a furnace or air handler to fan warm or cold air through your home’s ducts and through vents to cool the various rooms in the house.

For cool air, the air is blown across evaporator coils in the AC unit where all the heat is removed before pushing it through the home to cool the air.

What is a Window Air Conditioner?

So, how do window air conditioners fare in the window AC and central air comparison? Aside from having the lowest cost barrier to entrance, window units are an easy DIY project and can immediately relieve hot home dwellers from a muggy, hot house.

Window air conditioners are great for one room, but are fairly inefficient at comfortably cooling a whole house (unless the house is quite small).

Window air conditioning units are known to be rather drippy and noisy, but for some homes they do have merit over a central system. Like their name implies, window air conditioners are installed in a window.

They utilize two air cycles: the interior section of the unit blows air over evaporator coils to cool it down and blow it into the room; the exterior section of the unit blows outside air over its condenser to cool that down. The sections work together to keep the AC unit cool and the room cool.

Pros of Central Air Conditioning

When comparing window unit AC versus central air, it only makes sense that you consider the pros and cons of each unit. Let’s start with the pros of central air conditioning.

Central air conditioning is perhaps the most popular and desirable form of AC in home’s today, so adding it to your home will be attractive to any buyers should you choose to sell one day. It’s also very economical and can operate with modern smart thermostats so you can easily program the temperature of your home depending on your needs.


Central air conditioners are much more efficient than window air conditioners since they can easily work to cool your whole home at once. They are quieter, more out of the way, and very convenient to operate. 

Many modern versions of central air conditioners are made specifically to be energy-efficient and help you reduce the energy use from your AC. This can help you save money on your monthly electric bill and reduce your carbon footprint.

Split Home into Separate Cooling Zones

A central AC system can be retrofitted to be a multi-zone system. That means you can have different cooling zones in separate areas of the home to suit different people, schedules, and preferences. 

This means you don’t need to have a window AC unit in every room to ensure that the temperature inside is desirable. Your central AC unit can manage it on its own!

Easy Maintenance

Maintenance for central AC systems is very straightforward and pretty simple:  just get an annual inspection done and change out the air filters regularly. A key component of your AC unit is refrigerant fluid. 

The EPA has regulations governing the purchase, handling and disposal of refrigerants, which is why it’s best to leave AC repair and maintenance to knowledgeable professionals. Other than changing out the air filters, maintenance is pretty hands-off as a homeowner!


With regular maintenance, your typical central air conditioner should last about 10-15 years. After that, you may be better served to replace the unit altogether when costly repairs arise. 

It’s also good to replace units around this age since with advancing AC technology, you could get a more efficient machine that can save you more money in the long run.

Central Air Conditioning Cons

All air conditioner types have some type of con, even central air conditioners. Here are the main downsides to a central air conditioner for you to consider before deciding what’s best to use in your home: 

Requires Professional Installation

Central air conditioners require a professional to handle the installation job, otherwise you could end up with a system that doesn’t work properly or possibly at all. If you’re hoping to get a central air conditioner, let go of any hopes of it being a DIY installation job and contact a HVAC technician with the necessary skills (and licenses) to handle the job.

Additionally, if your home doesn’t have any ductwork already, these will need to be installed for your central air conditioner to operate. This is also a job that you should leave to the professionals to be sure you have as little heat and cooling loss as possible.

Can Waste Energy if not Managed Properly

The average central AC system can waste a lot of power if it isn’t managed properly, but it’s biggest advantages over window units are continual comfort and boosted home value. New, smart thermostats can greatly cut back on energy waste, which is highest when systems keep running when nobody’s home or if doors and windows are left open. 

If you can manage your central air conditioner well, it can be a very efficient system. If you manage it poorly, you can end up with a lot of energy and cooling waste. 

Cooling Loss

Many central air conditioners have ducts located in an unconditioned attic. This can lead to significant cooling loss—up to 20%—but that loss can be reduced or eliminated with proper insulation.

Additionally, if your ductwork has been improperly installed, you can have “leaks” where cool air escapes before it even gets to the desired rooms in your home. Insulate your attic and make sure all ductwork is installed by a professional to keep your cooling loss at a minimum.

Pros of Window Air Conditioner

If you only need to condition a single room or area, such as a bedroom for comfortable sleeping, a window unit may be just the ticket. A window air conditioning unit can also present an affordable, quick solution to the homeowner who isn’t prepared to upgrade their home to central air (especially if your home doesn’t have ductwork and you don’t want to tackle that large of an installation project).

Easy, Low-Cost Installation

Many homeowners who are handy and up for the task can manage a window air conditioning install on their one. Window AC units are simple, require minimal heavy lifting, and mostly involve hooking up the right sections and tightening some screws.

With just a little work, you can get your window air conditioner installed at a low cost and enjoy the air conditioning in your room for the remainder of the afternoon.

Effectively Cools a Single Room

Window air conditioners are very effective and even efficient at cooling a single room in the house. In fact, if you’re only needing a room or two to be cooled, window AC unit’s can even win out against central AC unit’s in terms of efficiency.

If you only need one room or a small space to have some extra AC, a window air conditioner could be perfect for you—plus, you can probably get the installation done quickly yourself.

Window Air Conditioner Cons

Just like central air conditioners, window air conditioners have their list of cons. While they can be a security risk on windows at the ground level, and many homeowners find them to be an eyesore, those aren’t the only con to consider when determining if a window AC unit is a good fit for you. Here are some common cons to consider:

Doesn’t Reach the Entire Home

Unfortunately, window AC units simply aren’t very effective or efficient at cooling an entire home—unless it’s a tiny home. They do a great job at cooling single rooms or small spaces but they don’t do much against managing humidity levels or cooling down temperatures in a family home.

If you need your entire home to be air conditioned, then don’t go with a window AC unit or else you’ll likely need to install one in every room, which gets expensive, difficult, and doesn’t end up being that efficient in the long run.

Must Choose Correct BTU

Buying a window AC unit with the correct BTU for the room size is extremely important. If too large for the space, you’ll have shorter run cycles instead of continuous running. Turning on and off frequently greatly reduces the dehumidifying effects of a window unit and increases noise.

Getting the fit right when installing a window unit can be tricky, and since units are designed to fit in a variety of window sizes, it can be difficult to get a perfect seal when installing them. Hot humid air has a tendency to leak in and work against the desired cool effect of the unit.

Unit Needs to be Protected from Inclement Weather

Many people remove window air conditioners for the winter, both for the view and because nothing seals out cold winter air better than the actual window.

Removing the unit protects it from the elements, but can present a storage challenge for some. Annual installation and removal also increases the wear and tear on the built-in accordion seals.

To properly install a window unit, home experts recommend using foam weather-stripping and caulk. For consumers who uninstall their unit each fall, this can be a tall order. Leaving it in all year long can shorten the product’s lifespan due to weathering, and expose your home to drafts and bugs in the offseason. No thanks!

How to Decide Between a Central or Window AC

So, which comes out on top in the AC window unit versus central air? 

Even with all this information, the answer is still, “it depends.” It depends on your budget, needs, home size, and preferences. If you have a small house and simply want to improve the airflow a little bit, a window air conditioner may be perfect for you. 

However, if you have a larger family home with many rooms and spaces that need cooling, a central system may serve you best and be most efficient. If cooling your home requires more than two window units, you’ll be better off with a central air conditioner.

This option wins out on both energy efficiency and comfort for most homes.

If you’re looking for the most efficient option and have the budget to handle the installation, a central air conditioning system is the more popular option for most homeowners (and home buyers). A central system is out of the way, efficient, and quieter than a window system, and you won’t have to worry extra care during inclement weather.

Call the Team at John C. Flood for Professional AC Services

Keep your central AC in great condition by calling the HVAC professionals at John C. Flood. The team at John C. Flood offers professional AC installation and repair services, and our call center is open 24 hours a day, seven days a week. You can always contact us during an emergency, whether you need AC repair or a whole new installation, we can help.

Reach out to us today at (703) 214-5611 to schedule your service!

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