How Much Electricity Does A Central Air Conditioner Use?

The easiest way to keep your home cool during summer is by using a central air conditioner – there’s no doubt about that. 

If you own one of these convenient appliances, have you ever wondered about its power consumption? Maybe knowing how much electricity your central air conditioner uses would help you determine whether it’s okay to leave it running continuously? 

In general, an AC unit that operates for about nine hours on a daily basis will use between three and five thousand Wh (watts per hour) during warmer months. 

Obviously, the exact amount of watts an air conditioning unit will use during one hour will depend on its size and power. There are several other factors that can significantly impact this number, such as the size of your home or the time of year. 

Would you like to know more about how AC units work in general? Or, as I mentioned above, maybe you’re interested in finding out how much electricity your particular air conditioner uses every day? 

Whatever the case, you’re in the right place. In this article, I will tell you everything you need to know about the energy consumption of central air conditioners and cover all the important questions related to this topic. 


Electricity Usage of Central Air Conditioners 

Woman adjusts the AC

Usually located outside of the house, air conditioners deliver cool air via the duct system. 

As stated above, the energy usage of one of these appliances can vary depending on several factors, like the energy costs at your location, time of use, outdoor/room temperature, etc. 

In states like Arizona, for example, most air conditioners run for around nine hours per day over the span of several months. In colder states – such as Minnesota – homeowners keep these appliances running for no more than three months during the entire year. 

It goes without saying that the most significant factor in wattage use is the climate of the place where you live. 

The energy use per air conditioner ranges from three to five thousand watts per hour. An average central air conditioner, which weighs between 2,000 and 2,500 lbs, will use between 3,300 and 3,500 watts per hour. 

An important thing to point out here is that these numbers are based on the average central AC unit running on the cool setting. If you’d be running just the fan of your air conditioner – in order to circulate air inside your home – used wattage would decrease significantly (to about 750 watts per hour). 

How Much Does It Cost to Run This Appliance? 

In the United States, running a central air conditioning unit on a monthly basis costs between $76 and $168. 

To be able to determine how much does it cost to run your AC unit, you’ll have to know many hours per day it’s running, its wattage, as well as what model of an air conditioner you’re actually using. You will also have to find out your location’s price per kilowatt-hour. 

The easiest way to do this would be to simply check the website of your energy company – there, you should be able to find everything you want about the current energy costs. 

Some energy companies even have convenient electricity usage calculators on their websites. This simple but extremely useful feature allows homeowners to determine their air conditioning costs by typing in the wattage of their AC units and the amount of time they’re using these appliances on a daily basis. 

How Do I Calculate The Cost of Running My Central Air Conditioning Unit? 

Residential central air conditioning unit

Coming to a rough estimation of how much it costs to run your air conditioner is actually quite simple. 

To do this, you will have to multiply the number of hours of electricity usage by the number of watts. 

For example, if the cost per kilowatt is $0.10, and your central air conditioning unit runs 9 hours per day and uses between three and five thousand watts per hour, the daily cost to run it will be somewhere between $2.70 and $4.50. 

In order to be able to estimate the electric bill for the next month, I would recommend tracking your home’s power consumption by re-doing this calculation once per month. 

Should I Leave My Central Air Conditioner Running All Day? 

With regular maintenance, both central air and window units should be more than capable of running from dawn to dusk. However, running a central air or window AC unit all day long isn’t always necessary to keep the air inside your house cool and fresh. 

I would recommend setting the fan on auto mode and the temperature at 70°F. If you do this, the air conditioner will maintain the room temperature at 70°F and it will turn on only to keep it that way. 

In case you notice a burnt smell or suspect that your central air or window air conditioner is not working like it should make sure to call an HVAC technician. 

If there’s something seriously wrong with your appliance and you don’t address the problem immediately, you’ll be risking further issues down the road, and these could be quite costly to repair and possibly even lead to a fire. 

How Many Hours Per Day Should Central Air Conditioners Run? 

Central AC unit housing

Unfortunately, there is no clear-cut answer to the question of how many operational hours per day is ideal for an air conditioner. In North America, the average number of running hours per day during summertime is nine hours. 

If it’s in a good condition, a quality AC unit should have no trouble running without stopping during the hottest summer days. As long as it’s maintained regularly, such an appliance will not be at risk of overheating and, consequently, catching fire. 

When it comes to the question of ideal hour usage, there are several different factors a homeowner needs to consider. 

In my opinion, one should not run an air conditioner for more than two hours a day during the late spring and early fall months. During the hot summer months, on the other hand, well-maintained AC units should have no trouble running nine hours a day or even continuously. 

For most people, the best way to save money on energy bills is by running central and window units for the shortest amount of time possible and only when necessary. To keep your home cool and save energy, make sure to use your model’s “auto” feature. 

Central AC vs. Window Units: Which Type is Cheaper to Run? 

When they’re used for the same amount of cooling time, window units are ⅓ cheaper to run than most central AC systems. However, it is still the size of your house that should determine which one of these two types of cooling systems is the best choice for you and your family. 

Do you have a standard four-plus bedroom house? If that’s the case, the most practical solution would be to use a central AC system. That’s because cooling such a property would require more than just one window unit. 

Besides, a window unit will almost always be designed for cooling small houses and apartments – this kind of appliance is not the best choice if you have a lot of square footage to cover. 

Is It Cheaper to Run AC or Fans? 

Living room fan

In terms of electricity usage, it is definitely much cheaper to run standing or ceiling fans – they use far less energy when compared to central AC systems. Even if your central AC system is Energy Star-rated, it will still use more electricity than any kind of a residential fan. 

Choosing to cool your home with fans comes with several advantages: 

  • First of all, these devices are very easy to move around. They are lightweight and moving them from one room to another for air circulation purposes is as easy as it gets. 
  • Fans can also assist your HVAC unit to do its job in a more efficient way. Using several of them during the hottest period of the year – when your air conditioner is running at peak efficiency – is guaranteed to help the appliance circulate the air inside your home. 
  • If you keep the kitchen ceiling fan running, you can safely lower the temperature setting on your air conditioner by 4°F – you won’t notice any difference. 
  • Finally, in an effort to reduce your home’s carbon footprint and save money, you could try using only the fans during nighttime. 

Turning off the air conditioner during the night won’t only give this device some time to cool down – after it has been in operation during the day – but also allow you to save more energy (and therefore more money) in the long run. 

What Time of Year is the Most Expensive to Run Central AC? 

Watt-hour meter

As you can already guess, summertime is when the electricity prices are at their highest. 

Electricity prices fluctuate in response to many different factors, including the availability of power, fuel costs, generation sources, and general energy demand. 

During summertime, when the demand for electricity is at its peak, more expensive sources of energy have to be used in order to meet this increased demand, which, in turn, results in higher prices. 

The reason why business and residential customers have to pay more than industrial clients is that distributing electricity to them costs more. As they require more electricity, industrial clients receive it at higher voltages – supplying them is more cost-effective and far more efficient. 

How Do I Get More Out of My Air Conditioner? 

Here are a couple of simple methods you may want to give a try if you’d like to get the most out of your AC unit: 

Keep it Under a Shade 

The efficiency of your air conditioner is almost certainly going to be reduced if its outdoor part is exposed to too much sunlight. 

I recommend building a shade above the outdoor unit. 

Keep the Filters Clean 

Man cleans air conditioner

Clogged AC filters are bound to hamper the efficiency and the overall performance of your air conditioner. They can cause it to get overworked, which, in turn, can increase the appliance’s energy usage. 

To prevent this from happening, keep the filters clean and have them replaced at least once a year. 

Keep It on Low Power 

Do not turn off your air conditioner just because you’ll be going outside for an hour or two. An air conditioner requires more power to start up than to run continuously. 

If you turn it off for an hour or two and then turn it on back again, the appliance will have to work harder in order to bring down the temperature again. 

The Takeaway 

The effort to keep the rooms cool and comfortable during hot summertime months can be quite difficult, and that is precisely why an air conditioner is crucial to managing the temperatures inside one’s home. 

Hopefully, this article has helped you learn more about the electricity use of these convenient appliances as well as about the measures you could take in order to lower the monthly cost of running one.