April 12, 2022
Ductless Mini Split in Festus, Mo

The hot, humid Missouri summers make having air conditioning a must. Unfortunately, keeping your home cool throughout the summer can result in steep energy bills. As a result, many people attempt to save money by using window air conditioners instead of having a central AC system installed. Still, the question is whether using window air conditioners is actually cheaper than a central AC system. To answer this, it is necessary to look more in-depth at the numbers.

Purchase and Installation Costs

There is no doubt that window air conditioners are far cheaper to purchase. You can also easily install the unit on your own, which means that you won’t have to pay for additional installation costs. On average, a 10,000 BTU window AC unit will cost anywhere from $200 to $500, whereas purchasing and installing a central air conditioner usually runs anywhere from $4,000 to $8,000. Of course, the actual cost depends on the size of the unit and how efficient it is. Still, purchase and installation costs are only one part of the equation as you also need to consider how much each cooling system will cost to run.

Calculating Energy Usage

To figure out how much each type of air conditioning system will cost to run, it is necessary to look at how much energy they use and how big of an area they can cool. The average window air conditioner produces approximately 10,000 BTUs of cooling. In theory, this should be sufficient to cool approximately 300 square feet of space. However, the reality is that a window unit is generally only suitable for cooling a single room or space since walls and doors will prevent the cool air from reaching other areas. On the other hand, a 10,000 BTU central air conditioner should be able to fully cool an entire 4,000- to 4,500-square-foot home.

How much energy the unit will use depends on how efficient it is. For window AC units, this is measured in EER (energy efficiency ratio) while central AC units are measured in terms of SEER (seasonal energy efficiency ratio). The average 10,000 BTU window AC will use around 900 watts of energy per hour. If you run the unit for eight hours a day, it would use around 200 kilowatt-hours of electricity each month. A similar-sized central AC unit will use around 3,000 watts of electricity per hour or more than three times as much as a window unit.

On the face of it, this would seem to indicate that the window air conditioners are by far the more energy-efficient option. This is true for small homes or if you live in a milder climate. However, the fact that window AC units cannot cool nearly as large of an area complicates the equation. Let’s say you live in a three- or four-bedroom house where you need a smaller window unit in each bedroom and a larger unit for the main living space. In this situation, you’ll likely end up spending far more to cool your house with window AC units than you would by installing a central AC system.

Another factor to consider is that the window air conditioners are not nearly as energy efficient as central AC units. Even the best, most-efficient window units will usually have a maximum efficiency of 10 or 11 SEER. This is still below the minimum efficiency rating required by law for all new central air conditioners. As of 2022, the minimum efficiency requirement for Missouri and other southern states is 14 SEER. You can enjoy even greater energy savings by opting for a more efficient central AC with a higher SEER rating. For instance, a central AC with a SEER rating of 23 will be around twice as efficient as the best window unit.

Central air conditioning is definitely the best option in terms of home comfort since it will be much more effective at cooling the entire house. Nonetheless, the amount of energy you save by using central AC instead of multiple window units may never be enough to offset the additional costs of purchasing and installing the central AC. For this reason, if you live in a smaller home, you may be better off using window units, but central systems are usually the better choice for larger homes and also in terms of overall comfort.

Expert Air Conditioning Services and More

If you’re considering your options for air conditioning, the experienced professionals at Bone Heating & Cooling are happy to help. We have been providing professional AC services to customers in Festus, MO and the surrounding area for more than 40 years, and we specialize in central AC systems, ductless mini-splits, and more. Our certified HVAC technicians can also assist with heating installation, repairs, and maintenance. Contact our team today if you have any questions or want to set up an appointment.

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