Air conditioner on outside of an old building

To have an idea of how much energy your air conditioner is going to use and what it will cost you, you need to understand how air conditioners use energy concerning their size. Assuming you aren’t an HVAC pro, this article will break down what all the technical terminology means so you can understand what all the numbers mean and how many amps does a 5,000 BTU air conditioner use.

What Is BTU?

BTU stands for British Thermal Unit, and it is the metric used to measure the power of an air conditioning unit. It is a metric that measures the energy in the unit. Each BTU gives the unit enough power to change the temperature of one pound of water by one degree Fahrenheit.

Air conditioners range in BTU and can be bought in 5,000, 6,000, 8,000, 12,000, 15,000, and 18,000 depending on the size of the space it is for.

HVAC systems are measured in BTU to help people understand how powerful a unit is and determine the size of a space it will be able to control the climate throughout your home.

What Is An Amp?

An amp is a unit used for measuring electricity. Amp is short for ampere and is the unit of measure for electrical current. The number of amps your unit uses to run will determine the amount of electricity it uses, therefore how it will impact your electricity bill.

How Many Amps Does a 5,000 BTU Air Conditioner Use?

On average, a 5,000 BTU air conditioner plugged into a 110-volt outlet only uses five amps. This is equivalent to about 550 watts, which are another unit used to measure electric currents.

Of course, the prices differ between energy companies and states. So it is difficult to determine what the price of running a 5,000 BTU air conditioner would be. But as a general estimate, it would cost between $30-$50 monthly to have it running.

For perspective, a 5,000 BTU air conditioner uses less energy than a top-of-the-line vacuum cleaner that often uses more than 6 amps of power.

How to Calculate the Number of Amps an Air Conditioner Needs

how many amps does a 5,000 BTU air conditioner use
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The formula for finding out how many amps an air conditioner will use is:

Air conditioner capacity (BTU) = Energy efficient rating /Power (in Watts)

You need to know the BTU and the energy-efficient rating in order to calculate the number of amps needed to keep the air conditioner running. If the formula is intimating, you can always search it online as many people have already done the math for you.

Is a 5,000 BTU Air Conditioner Large Enough?

If you are looking at a 5,000 BTU air conditioner, you may be wondering if it’s going to be large enough or powerful enough to cool down your space. Determining this is easy because the manufacturers do it for you.

The general rule of thumb is for every square foot you need 20 BTU to keep the room comfortable and cool. So a 5,000 BTU air conditioner can cool down a 250 square foot room with ease. If your space is smaller, 5,000 BTU is plenty.

If your space is closer to 300 square feet, but don’t care if your home is ice cold, you can get away with using a 5,000 BTU air conditioner. But if you try cooling a 500 square foot space with just 5,000 BTU, you will probably not experience the results you are looking for.

Bottom Line

Now, you should have a better understanding of how air conditioners are measured in both power and energy consumption. This can help you plan for your energy bills as well as determine the best air conditioner for your space.


How do I know what size air conditioner?

This piece has some hints on choosing your air conditioner size. But the best way to determine the ideal size for your space is to do some research into your kind of space. For example, mobile homes can require different levels of BTU.

The best place to find answers is on the manufacturers’ website where they usually specify the best size units for different sized homes.

What if I want to cool two stories?

If you are trying to cool a two-story home, you will probably need more than one air conditioner. Even if the home is small, air can struggle to flow up and downstairs as much as you would like it to.

How can I save energy?

There are ways to reduce your energy consumption. Turning off your air conditioner is obviously a great way to save some energy. And there are still ways to keep a room cool even if there aren’t any windows or AC.