Power Consumption of 2 Vs 1.5 Vs 1 Ton Split and Window AC

Air conditioners are one of the highest power-consuming appliances in our homes. If you regularly use AC, you will definitely see an increase in your electricity bill. Do you want to know how much power your AC consumes? Or are you wondering how to choose an energy-efficient AC? Then you are at the right place! AC power consumption depends upon several factors like the star rating, tonnage, and energy efficiency. By reading the AC label, we can easily calculate the power consumption. Read on to find out!

Power Consumption AC


How to Calculate AC Power Consumption Easily?

To calculate the power consumption of AC, you should note down the following factors:

  • Cooling capacity
  • Energy efficiency ratio
  • Type of AC


Different ACs have different star ratings and energy efficiency, so their power consumption will also vary. But still, we can use a general method to estimate the AC power consumption.

You should consider that for 1 ton of cooling, an AC consumes 1000 watts of power. Using this, we can calculate the power consumption of any AC with a different tonnage. Simply multiply the tonnage by 1000 watts. By this, the power consumption of 1 ton AC will be 1000 watts.

The power consumption of 1.5 ton AC will be 1500 watts. Similarly, the power consumption of 2-ton AC will be 2000 watts. This is an ideal scenario. In real life, the power consumption will slightly vary.


Split AC vs Window AC Power Consumption:

A split AC contains two units that are one indoor unit and one outdoor unit, whereas window ACs contain a single unit with all the parts such as a compressor, heat exchangers, and connecting pipes. Depending on the type of AC, the power consumption also varies as follows:

AC TypeTonPowerBill*
5 Star Split AC10.98 kW per hour4.9 rupees/ hour
1.51.49 kW per hour7.45 rupees/hour
21.73 kW per hour8.65 rupees/hour
3 Star Split AC11.56 kW per hour7.8 rupees/hour
1.51.93 kW per hour9.65 rupees/hour
21.15 kW per hour5.75 rupees/hour
5 Star Window AC11.06 kW per hour5.3 rupees/hour
1.51.59 kW per hour1.59 rupees/hour
22.13 kW per hour2.13 rupees/hour
3 Star Window AC11.17 kW per hour5.85 rupees/hour
1.51.76 kW per hour8.8 rupees/hour
22.35 kW per hour11.75 rupees/hour

*Calculated at 5 rupees per unit


Difference Between Power Consumption:

Let us understand the difference between the power consumption of 2-ton 5-star split AC and 2 ton 5-star window AC by calculating the monthly power consumption:

For calculating the power consumption of one month, we have to use the formula: power consumption per hour * number of hours of AC usage per day * 30

Considering daily usage as 6 hours:-

For a 2-ton 5-star split AC:

Monthly power consumption= 1.73 kW * 6 * 30

=311.4 kW per month.


If we calculate the cost at 6 rupees per unit, then 311.4 * 5 =1557 rupees per month.


Similarly, for a 2-ton 5-star window AC:

Monthly power consumption=2.13 kW * 6 * 30

=383.4 kW per month


At 5 rupees per month, the monthly cost will be 383.4 *5= 1917 rupees per month.


From the above calculation, you can clearly see the difference between the power consumption of a split AC and a window AC.


Inverter vs Non-Inverter AC:

Inverter vs Non-Inverter AC

The main difference between a non-inverter and an inverter AC is the type of compressor that is used. A non-inverter AC uses a single-speed compressor, which always runs on maximum, which means it can’t adjust according to the cooling requirements.

An inverter AC, on the other hand, uses a variable speed compressor that can adjust according to the cooling requirements. Because of this, an inverter AC consumes less power than a non-inverter AC.


Power Consumption of an Inverter AC:

Inverter ACs generally consume 5-10% less power than non-inverter ACs. This is because the compressor in the inverter AC will reduce its power consumption as the room starts to cool. An estimate for the power consumption of a 5-star inverter AC is given below:


Power consumption of 1 ton inverter AC = 0.55 kW per hour

Power consumption of 1.5 ton inverter AC =0.84 kW per hour

Power consumption of 2 ton inverter AC =1.13 kW per hour


By comparing these figures with the table for non-inverter AC, you can see that inverter ACs consume much less power than their non-inverter counterparts.


Factor Affecting AC Power Consumption:

Buying a power-efficient AC does look like the obvious choice, but there are several other factors that can also affect the power consumption of your air conditioner, such as:

  • Size of the room: Though every AC has a rating in watts, the real consumption changes according to the size of the room. An AC is designed to remove heat from the enclosed space, so a 1.5 ton AC will consume more power in a 200 sq. ft. room than it does in a 100 sq. ft. room. This is because there will be more heat and humidity in the former room than in the latter. 
  • Surrounding temperature: AC power consumption heavily depends on the temperature of the surroundings. If the room is very hot then the AC will be required to work more to cool the room. The power consumption also depends on the humidity of the air, as the AC does two things: reduce the temperature and remove humidity. So if the room has high humidity, the AC will require more power in order to make the room less humid. This is also a factor to consider when deciding the tonnage of the AC for a particular room. If the AC is too large for the room, then it may not remove humidity effectively. 
  • The number of people in a room: It is a commonly known fact that the human body gives out heat. The more people in a room, the more heat is generated. So, office spaces, classrooms, and community halls require ACs of higher tonnage. 
  • Energy efficiency ratio: EER is the ratio of the cooling capacity of an AC to its power consumption. In simple words, it tells us how efficiently an AC works. Higher the EER, the more the cooling effect for the same amount of power consumed. Usually, an EER of 9 is considered to be good for an AC. 
  • Energy star rating: If you have seen the label of an AC, you can see a few stars on it. These are the energy star ratings. It tells us how much energy we can save by using this particular appliance. Energy star ratings range from 1 to 5, the highest energy savings being the 5-star rating. 
  • Other electric appliances: Any electric or electronic appliance releases heat if used for a long time. Be it our TVs, laptops, or even mobile phones, these devices release heat in the room. As the heat increases in the room, so does the AC’s power consumption, as it has to work for a longer time without cutting off the compressor.


Tips to use an AC efficiently: 

No matter the type of AC you choose, there are certain tips to reduce the power consumption of your air conditioner.

  1. Keep the doors and windows shut to avoid hot or cool air entering the room.
  2. Set the temperature at a maximum of 8 degrees lower than the surrounding temperature. For each degree you lower, the AC consumes 6% higher power.
  3. Using a fan along with an AC will help cut down on energy consumption while also cooling the room faster.
  4. Regularly keeping up with AC maintenance and replacing the old parts will help make your AC more energy efficient.
  5. Switch off the AC at night once your room is cool enough. If you use AC for long hours during the day, try to switch it off every couple of hours.
  6. Only switch it on when you need it. It goes without saying that if you don’t plan on being in the room, you should turn the AC off. 


Air conditioners can definitely cool the rooms while also heating up your electricity bill. If you want to keep your expenses in check, choose an energy-efficient AC of the right tonnage depending on your requirements. Moreover, follow all the tips to use your AC more efficiently. Remember, the less power you consume the more you save!

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