How Much Electricity Does An AC Use

Posted by: Mas Broto
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An Air Conditioner can seem like a very important appliance when the temperature outside is 102 degrees. At that temperature, the Air Conditioner can run for a long time. How much electricity does AC use, and how much does it add to your electric bills?

To understand Air Conditioner running cost, we need to look at the rated BTUs of cooling output and the associated number of watts used when the unit is running. This is like a light bulb; you know, a 60-watt bulb gives off less light than a 100-watt bulb. The 100-watt bulb uses 100 watts in an hour, and then the other bulb uses 60 watts in an hour.

The BTU rating will tell us how big the air conditioner is and how big of an area it will cool. Window air conditioners can have a rating of 5,000 to 12,000 BTUs. The whole house, central air conditioners can have an output rating of 20,000 BTUs and more. Larger homes can be over 60,000 BTU.

The higher the BTU rating, the higher AC size, the more watts it takes to operate.

One advantage of having a good air-sealed and insulated home is the fact that the home can be cooled using fewer BTUs. The AC unit can be smaller, and the air conditioner power consumption will decrease.

To maintain a cool house and do it with fewer BTUs and less power consumption, the attic thermal barrier needs to perform. If the attic gets super hot and then easily heats up the living space, the air conditioner power consumption will be high. If the attic is separated from the living space with an effective thermal barrier, the air conditioner BTU rating can be reduced, and power savings result.

Central Air Conditioner Power Consumption

This is the large box-looking thing sitting behind your house with the fan in it. This outdoor AC unit (AC condenser) is connected to the furnace by a couple of copper refrigerant lines. The larger refrigerant line should be covered with insulation.

Central Air Conditioner with 36,000 Btu, 4500 watts, used 200 hours per month uses 900-kilowatt hours of electricity at 11.5 cents per kWh, that’s $103.50 per month.

In simple words: a 4-ton air conditioner running cost is about $100 per month.

Window Air Conditioner Power Consumption

How much electricity does a Window AC use generally is less than a Central AC. A window AC unit can use between 1,000 to 1,500 watts of electricity to run.

The size of window AC is often rated at about 12,000 Btu and uses 1500 watts per hour. If you use this air conditioner 200 hours per month, it will use 300-kilowatt hours of electricity, at 11.5 cents per kWh, that’s $34.50 per month.

To find the number of watts the unit uses per hour, you will need to get this information from the unit’s product sticker or the product specifications that can be found online.

Now that you know about how much electricity does AC use, you can plan ahead and find ways to conserve energy and lower your power bill. Please note that having the right size air conditioner is an important factor in lowering the energy bill.

Thank you for stopping by; I hope you’re staying cool this summer.

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Mas Broto
Have been in the heating and air conditioning (HVAC) industry for over 20 years. He is person that will grow and thrive to learn more about the HVAC industry throughout his career. Mas Broto is also a blogger, who's dedicated to bringing you the best knowledge to get ahead in the game of life.