How Much Power Does An Air Conditioner Use? 

How Much Power Does An Air Conditioner Use? 

Anthony Barnes

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Air conditioning units are major consumers of electricity. They account for nearly 20% of total U.S. electrical consumption.

The average home uses around 2,500 kilowatt-hours (kWh) per year.

That means that each air conditioner consumes enough electricity to power two homes for a whole year.

It takes approximately 3 kWh of electricity to operate an air conditioner.

This number varies depending on the type of system you have. For example, a window unit (see also ‘Window Unit vs Central Air Conditioner’) might only require 0.2 kWh of electricity. 

This article will talk about how much power different types of air conditioners use and how you can reduce your usage to save money.

How Much Power Does A Central Air Conditioner Use?

To calculate the average annual power consumption of your central air conditioning unit, multiply the size of your air conditioner by 0.1234.

If your air conditioner is 3 feet wide x 10 feet long (1 m x 3 m), then your air conditioner’s annual power consumption would be 1230 Watts (W).

You can use this information when comparing costs between brands.

Types Of Air Conditioning Units

There are three main types of air conditioning units: split systems, heat pumps, and room air conditioners.

All of these units share some similarities in their design but differ based on the way they produce cool or warm air.

Split System

Split systems consist of one compressor/condenser coil outside your house and another coil inside the house.

There’s also usually only one condensing fan, which circulates outside air over both coils.

One benefit of a split system is it uses less space than other systems as there is no need for ductwork; however, it requires more maintenance.

It is also not suitable for areas with very hot summers because the outdoor coil gets too cold during the winter months.

Heat Pump 

Heat pumps work similarly to a radiator except that instead of cooling down water, they cool air.

Most models of heat pump air conditioners come with two separate compressors, one for the indoor coil and one for the outdoor coil.

Although heat pumps are slightly more expensive than split systems, they use less energy to run and maintain due to their high-efficiency rating.

They can also stay at an optimal temperature throughout the year making them perfect for mild climates.

However, heat pumps require regular cleaning and lubrication to keep them operating efficiently.

Unlike split systems, there’s no need for ductwork.

Room Cooler

Room air conditioners fit into any room where there is already an existing air supply such as through a window.

Like split systems, room air conditioners have one indoor and one outdoor coil.

They are extremely compact and quiet compared to larger central air conditioners.

These units have high-efficiency ratings. However, they do not circulate fresh air unless you open windows.

Instead, they pull air from the outside through holes in the side of the room cooler and then blow that same heated air out into the room.

Because these cooling systems don’t bring the inside air directly into contact with the evaporator coil, they tend to use more electricity.

Additionally, if you’re concerned about energy bills, this could present an issue.

Another disadvantage of room coolers is that they aren’t suited for humid climates since they don’t allow for ventilation.

How Much Power Does A Portable Air Conditioner Use?

How Much Power Does A Portable Air Conditioner Use?

Portable air conditioners (see also ‘How To Vent A Portable Air Conditioner Without A Window‘) take up minimal space, weigh little, and provide efficient, cost-effective cooling.

The great thing about portable air conditioners is that they can be moved around your home without having to worry about any installation issues.

Their low weight makes them easy to move around, and their smaller footprint allows them to fit almost anywhere.

Most units come pre-assembled, so all that’s left to set up is the power cord and filter box.

Some portable air conditioners even charge themselves!

So what kind of power will my portable air conditioner use?

With several different factors involved, determining how much power a portable air conditioner uses depends largely on its internal components and whether or not it has any options available.

The first step when calculating the amount of power used by a particular unit is identifying the model itself. 

Not sure which one to buy? Check out a power calculator.

Once you know which model we’re dealing with, you can go through each component to figure out how many watts of power it takes to run.

Then, once you’ve added together all the individual components and their wattage requirements, you can add those figures up and multiply them by 100 to obtain a final estimate of how much total power was used during operation.

How much does a portable air conditioner use per hour?

Most portable air conditioners use somewhere between 6 and 7 watts per hour.

That means that a portable air conditioner runs on just 4 amps of current.

An average household circuit breaker should be able to handle this load comfortably, but if yours has trouble, upgrading may be necessary.

As always, it wouldn’t hurt to check with a licensed electrician before trying to upgrade your current electrical system.

How Much Power Does A Window Air Conditioner Use?

Window Air conditioners typically utilize less power than other types.

Window models only need to operate at full capacity when the weather gets hot enough to force the AC unit off its regular cycle.

This is usually triggered when the interior temperature reaches 80ºF.

Since these units run less often without being fully blown, they consume less power during their normal cycles.

And because they are located outdoors, they also benefit from additional wind flow, thus requiring fewer fans to push the same amount of air.

If you want the most bang for your buck, look for a window air conditioner that is both efficient and quiet.

Efficiency refers to how well the unit works while running. Quiet refers to how little noise the unit produces.

Look for an ENERGY STAR-qualified product as these products have been tested and certified for efficiency.

Additionally, these units have built-in timers that automatically turn on/off based on exterior conditions.

You can also find a wide range of programmable features that allow you to customize how long the unit stays to save energy costs.

Factors That Affect Air Conditioner Power Usage 

One of the biggest differences in cooling equipment is in the way that heat moves into and around the air conditioning unit.

While air conditioners vary widely in size and design, there are some important things to consider regarding how power consumption is measured and why your specific unit might require more or less electricity than others.

Let’s examine the main areas where air conditioning systems differ and how they impact the amount of power required:



One area where we see significant variations in power usage is in the fan motor.

Because fans vary significantly in speed and size, they can account for anywhere from 2% to 50 % of installed air conditioner power consumption.

In general, the larger the fan, the higher the power required.

For example, a typical 20 cubic feet /minute (CFM) forced convection blower would use roughly 8 watts of power.

On the other hand, a high-capacity ductless mini-split system installed in a large attic could use over 30 CFM and requires far higher wattages.

What type of fan does your particular model use? Is it an impeller fan? Or perhaps a variable frequency drive (VFD)? 

Ductwork Design 

When selecting a duct for your new system, keep in mind that bigger systems tend to require more airflow.

Therefore, you won’t necessarily need more ductwork.

However, unless you plan on moving the unit daily, you need to make sure that the unit fits comfortably inside of the existing ductwork.

It is typical to install either 1.5″ or 3″ ducting depending on the room size and airflow requirements.

If necessary, you can add a small expansion unit. Expansion units are designed specifically to increase the capacity of smaller duct sizes.

Most times, this means using a different sized piece of tubing (instead of just making a straight cut).

The difference in cost between a standard 1.5″ or 2.0″ diameter duct vs. a 3″ diameter duct is negligible ($40-$60 per linear foot), so choosing one should be fairly straightforward.

How To Decrease Air Conditioner Power Usage

There are a few ways to reduce the amount of electricity used by your air conditioner.

First, select the mode that uses the least amount of power – usually Auto.

Second, set the thermostat slightly below the comfortable temperature, even if you’re sleeping.

Third, clean out the filter weekly rather than monthly. Fourth, leave the indoor coil free of any object which may cause corrosion, like dust or hair. 

There’s no denying how great it feels to come home after work to a cool house.

But not every home has the luxury of a dedicated A/C unit to make those days better.

Fortunately, installing an energy-efficient system doesn’t have to break the bank. A/C efficiency codes were created to provide both homeowners and contractors with affordable solutions – and these codes also promote environmentally friendly practices, as well!

The condenser coil is the component of an air conditioning system that removes heat from the refrigerant gas and transfers it away from the system through the outside air.

It plays an important role in keeping your home cool when the compressor isn’t running.

As a result, you’ll want to take care of it during the summer months, when the temperatures soar.


Air conditioners (see also ‘Trane Vs Carrier Vs Lennox Air Conditioner Review’) are an important part of staying cool during hot weather – and even though they increase your electricity bill, there are ways you can reduce power usage such as by completing regular maintenance tasks and making sure you buy an efficient model.

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By Anthony Barnes

Anthony Barnes is the founder of Water Heater Hub and a second-generation plumber by profession. Before developing Water Heater Hub, Anthony Barnes was a full-time plumber, and he has undertaken a wide variety of projects over the decades. As a second-generation plumber, it was easy for Anthony to get used to the technicalities of all from a tender age