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Central Air Versus Window Air Conditioning: Which is More Efficient?

Outdoor air

Heat waves and heavy hanging humidity can really leave the DMV area desperate to cool off and 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?

People usually wonder about central air versus window air conditioning. Which system is the best bang for your buck? Which is more efficient and will keep your bills lower? As with so many things, the frustrating answer is often “it depends.”

To get the cooling solution best for your home, you should understand the pros and cons before you invest.

Your HVAC system: Understanding the basics

Living room

Central Air Conditioning Efficiency: Pros and Cons

As a favorite feature among home buyers, central air conditioning can boost your home 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. 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 Conditioning Pros

If your home doesn’t have any air conditioning right now, but it has a furnace for heating, that’s great news! A split system air conditioner is by far the most economical option for central air conditioning. Most central AC units utilize a split system, placing the condenser and compressor outside the house and the evaporator inside, usually in the cabinet containing your furnace.

Some central AC units can split the home into separate cooling zones for added efficiency. Even for a typical split system using all your ductwork, a modern smart thermostat can be programmed to decrease energy waste and reduce your electric bill.

As for upkeep, maintenance on a central AC unit is pretty straightforward: just get an annual inspection done. 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.

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 with advancing AC technology you could get a more efficient machine.

Central Air Conditioning Cons

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.

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

One of the joys and sorrows about air conditioning is that you hardly think of it until it breaks. If you skip annual maintenance on your system, you may shorten the lifespan of the unit, get lower quality cooling and be in for unexpected repairs.

Window air conditioning

Window Air Conditioning: Pros and Cons

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 rarely can they comfortably cool a whole house, unless it is quite small.

Window air conditioning units are known to be rather drippy, noisy affairs when you need them most, but for some homes they do have merit over a central system.

Read about the History of Air Conditioning

Window Air Conditioning Unit Pros

If you’ve ever felt mystery condensation drip off of window AC units stacked up the side of an apartment building, you might assume that these cooling machines are not the most energy efficient devices. However, window units can occasionally win out against central air conditioning in an efficiency face off.

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.


Air conditioning units in windows

Window Air Conditioning Cons

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.

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!

And The Winner Is....

In the debate of central air versus window air conditioning, modern central air conditioners are more efficient and smarter than ever. 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.

Regular care goes a long way

Keep your central AC in great condition by calling the HVAC professionals at John C. Flood. Our call center is open 24 hours a day, seven days a week, so you can always contact us during an emergency. Whether you need AC repair or a whole new installation, we can help. Give us a call today!