Is Running Cental Air Cheaper Than Running Three Wall Air Conditioners?

Air conditioning makes the most popular summer days more satisfying, but rising energy prices and the growing awareness of energy conservation and resource depletion requires you cool your house as cheaply and energy efficiently as possible. Deciding which cooling system will save you the most — three window air conditioners or a central air unit — depends on a few factors. Cooling your home with the proper system saves you money and power, and keeps you completely comfortable regardless of the temperature outside.

Comparing Energy Usage

Considering that the average house uses more power for heat than for any other appliance or accessory, if you want to save money on your utility bill, carefully consider your cooling options. A central air unit consumes more energy to cool your property. As Mr. Electricity says, a window unit consumes anywhere from 500 to 1440 watts to run, while a 2.5 ton central unit (about the size for a typical 1,500- to 2,000-square-foot house) uses roughly 3,500 watts. It’s not simply about the magnitude of place cooled, but the fact that central air requires the furnace, also. The air doesn’t flow to the rest of the home with no furnace blower — so more running parts equal a larger power draw.

Price of Unit Installation

It’s simple to see a central unit consumes more electricity than a window unit, but there’s more to your cost than only the power draw. As soon as you factor in the price and cost of installation, your cost per use may rise substantially. Dividing the whole cost and installation labor cost by the weeks you use it dramatically illustrates the true cost of only using the air conditioner, without figuring in the utility bill. Window units sell for a good deal less than central units, and also the installation generally is do-it-yourself.

It’s Not All About the Unit

Another factor when determining that heat unit is best for your circumstances is the state of your existing HVAC system. No matter how efficient your central air unit, even if the ducts that the cool air moves through are filled with holes, or poorly insulated and exposed to temperature extremes, the efficacy of the entire system goes down — and the cost goes up. If you decide to run a central air unit, insulating your ducts, and inspecting and maintaining the entire system is important, even though it adds to the cost. Compared with window units, which blow right into the room and need little but occasional cleaning unless they move out, a central unit again costs more.


Although it costs more to purchase and install a central unit — and responsible owners also spend more on annual service calls for maintenance and inspection — if you intend to trendy three or more rooms, the cheapest and energy-efficient alternative is your central unit. A central unit has higher resale value, which means you recoup more of the investment if you sell your property. The weightiest factor, however, is that three window units typically use more electricity than a single central unit. Also look at that three rooms likely is a large part of the house, and each time you travel between heat zones using a window unit, you are leaking cool air, making your unit work harder. But neither unit will get the job done efficiently and save money unless it’s correctly sized. Always research your choices before purchasing.

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