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How Many Amps Does a Window AC Use?


If you are looking to own a window air conditioner, maybe one of your biggest concerns is the amount of electricity it would consume. Before choosing an AC unit for your home, gather the necessary information about amps to ensure that you get the best fit for your money.

Scroll down and continue reading this guide to learn how many amps a window air conditioner uses.

What are Amps in My Window Air Conditioner?


Amps or Amperes are units of electricity. They are used to define how much electricity is used in a specific electrical appliance. To simplify, amps power up your window air conditioner.

Electric current, a currency expressed in amps, is the number of electrons that flow through an electrical device.

What’s the Difference Between Voltage, Amperage, and Wattage?

When you look for an air conditioner, you’ll notice that they are often labeled with three different electricity measurements: voltage, amperage, and wattage. Knowing the difference between these can assist you in determining which air conditioning unit will be the best option for your space. Here’s a quick comparison between the three:

  • Voltage: Voltage is the electrical potential between two points. High voltage machines are drawing low amps, which allows the air conditioner to last longer. The most common voltage ratings for window AC units are 115, 125, and 220 volts. One volt is equivalent to one ampere through the resistance of one ohm. 
  • Amperes: Often called “amps,” Amperes tell you how much electricity flows between two points in a given time. Appliances require a circuit to measure how many amps are drawn from it, or they will trip the circuit breaker.
  • Watts: Wattage measures how much energy appliances use to convert electricity into a different type of energy. We commonly see watts on our electric bill to show how much power we’ve used in a particular month.

How To Calculate the Number Of Amps in Air Conditioners

Air conditioners are usually sized based on their heat capacity, measured using British Thermal Units or BTU.

If you want to know how many amps a window air conditioner uses, you have to calculate the following:

  1. From BTU (British Thermal Unit) to electrical power (measured in Watts).
  2. From Watts to electrical current (measured in Amps).

You can use this equation:

Air conditioner capacity (BTU) = EER/P (in Watts)

EER or Energy-Efficiency Rating is usually found in specification sheets of 5,000-18,000 BTU air conditioners. On average, EER ranges from 8 to 12. 

How Many Amps Can a Window Air Conditioner Use?

Amps are significant in measuring window air conditioners’ overall electrical energy and cooling capacity. The British Thermal Units, also known as BTU rating, will determine how many amps a window air conditioner uses.

A lower BTU rating means a lower amp draw. Furthermore, air conditioners with higher British Thermal Unit ratings require higher amps.

5000 BTU Air Conditioner

If your air conditioner uses 5000 BTU, it can have 3.62 to 5.43 amps. 

8000 BTU Air Conditioner

Air conditioning units with 8000 BTU cooling capacities have 5.80 to 8.70 amps. These units are typically window-type and portable type. 

12000 BTU Air Conditioner

12 000 BTU air conditioners can have 8.70 to 13.02 amps. These cooling units can be window units, portable, mini-split type, or central air conditioners.

1500 BTU Air Conditioner

15 000 BTU rating air conditioners have much higher ampere ratings at 10.87 up to 16.30 amps. These types of units are window and portable air conditioners.

How Can I Save Electricity?

The current used by an air conditioner depends on several factors, such as voltage, cooling capacity, and size. These will later affect your overall electric consumption. Below are the tips you may do to have an energy-efficient window unit.

Buy the Right Air Conditioner Size

One way to save on your electric bill is to find the right size of air conditioning unit. Since the current rating of an air conditioner depends on its size and cooling capacity, finding the right air conditioner size is the best thing to do before your purchase.

If you get an air conditioner that’s too big for your space, you’re drawing more power than what is necessary. Oversized units don’t need to run longer to remove all the humidity in the air. On the other hand, small units will fall behind and must run almost continuously to cool your home. Both translate into spending more money on the electricity bill. 

Plug the Window AC Unit Into Its Dedicated Outlet

Depending on the size of your air conditioner, the window unit may require a dedicated circuit in your home. This means that no other appliances can be plugged into the outlet simultaneously. 

Although smaller units with 15 amps can operate off a standard household outlet, it is still best to plug the hard-wired window air conditioner into its dedicated outlet.

You should also ensure that you avoid using an air conditioner with higher amps than the circuit breakers in your home. Once an air conditioner requires above 30 amps of current, you should get a 240 volts breaker. 

Use the Thermostatic Controller

Most window units have a built-in timer that turns them off after several minutes. These automatically shut off the cooling unit when the air conditioner is not being used. In addition, it is best to utilize the “cool night” feature of some window units. 

Remember that the window air conditioner draws more amps when the outside temperature is higher. By using these features of your air conditioner, you can minimize your electric consumption.

Final Thoughts

10 Advantages of Split Type Aircon

Due to their portable and easy-to-install nature, window air conditioners have quickly become a favorite among homeowners. However, the electricity consumption of window air conditioners is typically more powerful than standard home appliances. When purchasing one of these units, you should learn how much an air conditioner consumes to pick the right model for your space.

Although it is rare to calculate how many amps an air conditioner uses, it is still important to measure the amount of electricity that is flowing through the circuit. This way, we will know if your unit is pulling more energy than it should.

JP Reyes

JP has been in the aircon industry for almost as long as he has been alive. As a child JP would help his tatay fix aircon units at their junk shop in Cavite. After graduating UP in the early 2000's, JP then started his own Aircon servicing business and within 5 years had 10 shops in 8 different cities. Fast forward to today and JP brings all his experience and expertise online to give readers trustworthy advice and reviews about Air-conditioning buying, servicing, cleaning and repair in the Philippines.

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