Most homeowners know how expensive the electricity bill can get during the summer when high temperatures force many people to run their air conditioning units almost around the clock. The question for many households is how to keep the budget in check when the heat is rising. The first step towards cooling your house affordably is understanding how much power your AC unit consumes.

An AC’s power consumption increases based on the unit type, and the amount of time it is on and running. For example, the most common air conditioning unit in modern houses is central heat and air systems, which demand an average of 3,000 watts/hour to cool the home.

It’s easy to imagine how fast that level of energy consumption turns into the massive energy bills we all fear in the summer months. By understanding when and how your AC unit uses the most energy, you’ll be well equipped to maximize your energy savings. Keep reading to learn more details about how different types of AC units consume power.

How Much Power Does AC Use on Average?

Most modern homes feature central heat and air as a selling point of the house, but these are some of the biggest energy consumers responsible for running up that summer electricity bill.

The average central AC unit utilizes roughly 3,000 watts/hour. Central ACs may be convenient, but they can be costly, incurring much higher monthly bills than window units or fans.

Why Is Your AC Bill So High?

Your AC bill is high because central AC units inject cool air into the entire house rather than one room. Because cooling a house requires more energy than cooling a room, central AC consumes much more energy per hour than any other method of home cooling.

Is It Cheaper to Run AC or Fans?

Many central AC units have a fan feature, which essentially uses the AC system like a whole house fan, drawing air from outside and circulating it through the house.  Running your AC on fan mode can help keep the power bill down during the summer months because it is cheaper to run fans than AC.

Running the central unit’s fan-only function at night, when it can draw cooler air from outside through the house, will keep the temperature down without having to run the AC unit itself. The fan feature uses much less energy per hour than the AC, which makes it an alternative for users looking to save money.

The downside of relying on the fan-only mode is that it will continue drawing air from outside even as it heats up during the day. Running a central fan at night allows users to put off turning on the AC until later in the day, but if the temperature is high enough, you’ll eventually have to switch it on.

Is It Cheaper to Keep AC Running All Day?

It is not cheaper to keep your AC running all day. Leaving the unit on and running can increase your energy costs. If you want your home to be cooled by the time you arrive back, consider investing in smart home technology that allows you to schedule when you turn your AC on and off.

How to Lower Your AC Bill

Some energy providers offer lower rates at certain hours of the day during the summer. Look up the peak energy hours listed by your energy provider and run your AC accordingly. This can help mitigate the cost of maintaining a livable temperature in your home as summer temperatures break records.

Window Units Power Consumption

Window units are beginning to be a thing of the past as more houses and apartments are being built with central AC. Their mobility, energy efficiency, and overall lower costs, however, still make them a popular option for college students and in older buildings.

Window units by necessity are much smaller than central units and therefore require less energy. On average, a window unit will consume roughly 900 watts/hour. Compared to the massive amount of energy central AC units gobble up per hour, it’s easy to understand why window units tend to incur lower monthly bills.

The downside of using window units as opposed to central heating and air systems is, most crucially, the quality of air cooling provided. Window units vary in both price and quality. While different companies may have minor variants in power consumption, as a rule, you get what you pay for.

That said, window units in the lower price range have their place. Many people choose to equip a smaller room, such as a bedroom or nursery, with a secondary window outside so that they can control the climate of that room separately from the rest of the house.

With a window unit, managing power consumption is as simple as remembering to turn the unit off when it’s not needed. If the temperature in the room is comfortable, switch off the window unit.

A window unit takes a reading of the temperature of the room and only cools when the temperature rises above the temperature setting, but it’s still consuming energy when the temperature is lower than the setting. Switching off the window unit when the temperature is lower than the setting is a small way to save energy. Make sure to turn off the window AC unit whenever you’re not in the room.

Why Do AC Units Consume So Much Energy?

During the hottest times of the year, many users leave their AC running all the time. The electricity demanded by the compressor to constantly pump refrigerant through the system causes the excessive rate of energy per hour.  AC units may also consume more power if they are out of repair.

AC units require either a liquid or gas refrigerant to be circulated throughout the system whenever it is in use. Essentially, if the compressor has to work harder to circulate the refrigerant through the system, the whole unit will require more power to operate. Scheduling regular maintenance for your AC unit can help ensure it runs as efficiently as possible.

Cost-Effective AC Alternatives

If you’re looking for ways to reduce your monthly energy spending, finding alternatives to a central AC unit is a great way to start. These alternatives require an initial investment, which effectively prevents many homeowners from switching away from central AC.

Once installed, however, having an alternative cooling solution gradually pays for itself with the money users save by not using a power-hungry central AC.

Whole-House Fans

As mentioned earlier, central or whole-house fans effectively cool the house by drawing air from outside and circulating it through the house. This method of climate control is most effective when the temperature outside is more desirable than inside.

Whole-house fans are a popular and relatively affordable option as an alternative to centralized AC. You can expect to pay anywhere from $700-$3,000 for the installation of a whole house fan, including labor.

Attic Fans

Attic fans, while not as effective as a whole-house fan, perform a similar function by releasing hot air that has risen to the top of the house out via fans or vents. Attic fans and vents are more affordable to install than whole-house fans. Attic vents range from $350-$900 on average.

Solar Energy

Another way to reduce the amount you’re spending on cooling your house is to switch to solar energy. Solar energy is not only more affordable, but it’s also a renewable, eco-friendly alternative to traditional power sources.

Solar panels are more expensive to install than the other options listed. However, the savings made available by solar power apply to more than just the AC. For this reason, solar energy is an excellent alternative if you have the means to install the panels.

Consider the Insulation

One of the most significant factors that cause AC units to overconsume power in the process of cooling a house is that cold air escapes and hot air is allowed in from outside.

If you live in an older home with its original insulation, you know how easy it is for both cold and heat to get through windows and walls. Beyond keeping windows and doors closed while you’re running the AC, there isn’t much to be done unless you’re ready to put in new insulation, which is a major undertaking.

Standing and Ceiling Fans

Finally, don’t discount the value of a ceiling fan or a well-positioned standing fan. These fans only consume between 40-100 watts/hour, a minuscule fraction of the power consumed by a central AC unit.  Running a standing or ceiling fan instead of the central AC as much as possible is a great way to reduce your overall energy spending.


If you’re cooling your house with a central AC unit over the summer, you can expect to spend a lot of money on electricity every month. Central AC units are one of the most energy-consuming climate control options; however, many users still prefer them for their simplicity and effectiveness.

There are other methods of cooling your house aside from using central AC, which uses less energy and is more economically efficient, such as solar-powered, solar-powered air conditioning, and renewing the insulation of the house.

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