How Much Electricity Does a Portable AC Use?

Portable AC

Portable ACs have become increasingly popular. They have a flexible and convenient way to cool specific areas. 

Also, they do it without the need for extensive installation or modifications to the building like installing a whole central AC unit. 

People like them because they provide cooling wherever you need it. Even if you’re renting a place or can’t modify your home’s structure, you can still enjoy the cool breeze. 

The question is how much electricity does it consume? 

Well, we are about to find out.

Understanding How Your Portable AC Works

Imagine a portable air conditioner as a magical box that takes in warm room air and turns it into cool air. It does this using a special liquid called refrigerant. 

Let me break it down for you: 

  1. Sucking in Warm Air

The AC unit has a hose or vents that you place near a window. It sucks in warm air from the room through this vent.

  1. The Cooling Magic

Inside the AC, the refrigerant absorbs the heat from the warm air. This makes the refrigerant turn from a liquid into a gas. Easy science right there folks. 

  1. Compressor Squeeze

The AC has a compressor that squishes the gas refrigerant. When gas is squeezed, it gets hotter.

  1. Hot Air Outside

The hot, squeezed gas goes through another set of coils (pipes) that are outside the AC. Here, the heat from the gas escapes, making the gas turn back into a liquid.

  1. Cool Air Creation

Now, the refrigerant is a cool liquid again. It goes through a valve, which makes it expand and turn into a very cold gas.

  1. Cooling the Room Air

This super cold gas runs through another set of coils inside the AC, where the warm room air passes over. The cold gas then absorbs the heat from the room air, making the air cooler.

  1. Releasing Hot Air

The warm air that’s left after its heat is taken away is blown back into the room. But the heat from the room air is now in the refrigerant gas.

  1. Repeat Process

The AC keeps repeating this process by sucking in warm air then cooling it using the refrigerant, and releasing cool air until the room gets as cool as you want it.

Know The Parts of The Portable AC


The compressor is responsible for circulating the refrigerant gas through the system. It compresses the low-pressure, low-temperature refrigerant vapor into a high-pressure, high-temperature gas.


Picture this like a radiator for the AC. The high-temperature gas from the compressor flows through here. It releases its heat, and as it cools down, it turns back into a liquid. It’s like letting out a big puff of hot air.


This part is inside your room, and it’s like a super cold sponge. The liquid from the condenser goes here and becomes a cold gas again. It absorbs heat from the air in your room which then makes the room cooler.


The fan helps circulate the air within the room and also blows air over the condenser and evaporator coils. It assists in transferring heat to or from the refrigerant and makes sure the air is consistent in cooling or heating inside the room.

4 Factors That Influence The Electricity Consumption

  1. Cooling Capacity (BTUs)

Think of cooling capacity like the “power” of the AC. It’s measured in something called BTUs (British Thermal Units).

Basically, the higher the BTUs, the more powerful the AC is at cooling. However, if your AC is too powerful for your room, it might use more energy than needed.

It’s like using a super big flashlight when a smaller one would do.

  1. Energy Efficiency Ratio (EER)

EER tells you how well the AC uses electricity to cool. Higher EER numbers mean the AC is better at turning electricity into cooling.

It’s like comparing two cars, one that goes farther on the same amount of gas. Higher EER ACs are like efficient cars that give you more miles per gallon.

  1. Room Size and Insulation

Imagine your room like a cozy blanket fort. 

The bigger the room and the thinner the blanket walls, the more energy your AC might need.

Good insulation is like a thick blanket that keeps the cool air in and the warm air out. If your room is like a big tent in the cold, the AC will have to work harder.

  1. Climate and Ambient Temperature

Think of this like a battle between the AC and the outside weather. If it’s super hot outside, your AC will need to work more to keep your room cool.

It’s like trying to cool down a room while someone is constantly heating it from outside. It’s as simple as that. 

How Is The Electricity Consumption Measured

When we talk about how much electricity portable AC uses, we use a special unit called a “kilowatt-hour” or kWh.

The Energy Efficiency Ratio

The EER represents the cooling output (measured in BTUs) divided by the energy input (measured in watts).

A higher EER signifies better efficiency, indicating that the unit can cool a given space using less electricity. 

By grasping the EER, you can compare different portable AC models and make informed decisions to choose units that provide effective cooling while minimizing electricity consumption, ultimately leading to cost savings and reduced environmental impact.

Estimating The Electricity Consumption 

  1. Identify the Cooling Capacity (BTUs)

Look for the cooling capacity of the portable AC unit. It is usually measured in British Thermal Units (BTUs). This information can be found on the unit’s packaging, user manual, or manufacturer’s website.

  1. Calculate the Energy Efficiency Ratio (EER)

The Energy Efficiency Ratio (EER) measures the cooling efficiency of the AC unit. It is calculated as the ratio of cooling output (in BTUs) to the power input (in watts).

The formula for EER is:

EER = Cooling Capacity (BTUs) / Power Consumption (Watts)

Check the manufacturer’s information to find the cooling capacity and power consumption of the AC unit.

  1. Estimate Usage Hours Based on Individual Needs

Figure out how many hours per day you plan to use the portable AC unit. This could vary based on your comfort preferences, room size, outdoor temperature, and budget.

For example, you might use it for 4 hours during the day and 8 hours at night.

  1. Calculate Daily Energy Usage

To calculate the daily energy usage of the portable AC unit in kilowatt-hours (kWh), use the formula:

Daily Energy Usage (kWh/day) = (Power Consumption in Watts / 1000) * Hours of Use

You can find the power consumption information in the manufacturer’s guide and you know the number of you plan to use the portable AC in a day.

  1. Calculate Monthly Energy Usage

To calculate the monthly energy usage in kWh, multiply the daily energy usage by the number of days in a month:

Monthly Energy Usage (kWh/month) = Daily Energy Usage (kWh/day) * Number of Days in Month

The number of days in a month can vary, so you might use an average value (e.g., 30.4 days) for convenience.

  1. Consider Other Factors

Keep in mind that factors like room insulation, local climate, and personal usage patterns can affect the actual energy consumption.

If you want a more accurate estimate, you could monitor your electricity meter before and after using the AC unit for a specific period.

  1. Compare Costs

To estimate the cost of running the portable AC unit, multiply the monthly energy usage (in kWh) by your local electricity rate (usually expressed in $/kWh).

This will give you an idea of how much it will cost to operate the portable AC unit each month.

To compare energy supplier rates, you can use comparison sites such as chose texas power.

In-Depth Practical Use Examples 

Let’s look at some detailed practical examples we have for you to better understand the electricity consumed by your portable AC in different situations.

Small Room vs. Large Room Portable AC

Consider two portable AC units with different cooling capacities. The small room unit has a cooling capacity of 8,000 BTUs, while the large room unit has a capacity of 14,000 BTUs. 

Assuming both units have the same Energy Efficiency Ratio (EER) of 10, let’s compare their energy consumption for a day of use:

Small Room Unit: EER = 10, Energy Input = 800 watts (8,000 BTUs / 10), Daily Energy Consumption = 8 kWh (800 watts * 10 hours / 1000)

Large Room Unit: EER = 10, Energy Input = 1,400 watts (14,000 BTUs / 10), Daily Energy Consumption = 14 kWh (1,400 watts * 10 hours / 1000)

This example tells us that a larger cooling capacity requires more energy, emphasizing the importance of selecting the right-sized unit to avoid unnecessary energy consumption.

Energy-Efficient Portable AC vs. Standard Unit

Consider comparing an energy-efficient portable AC with an EER of 14 and a standard unit with an EER of 8.

Both units have the same cooling capacity of 10,000 BTUs. Let’s compare their energy consumption for a day:

Energy-Efficient Unit: EER = 14, Energy Input = 714 watts (10,000 BTUs / 14), Daily Energy Consumption = 7.14 kWh (714 watts * 10 hours / 1000)

Standard Unit: EER = 8, Energy Input = 1,250 watts (10,000 BTUs / 8), Daily Energy Consumption = 12.5 kWh (1,250 watts * 10 hours / 1000)

This example shows us how an energy-efficient unit can significantly reduce energy consumption for the same cooling output.

Varying Usage Patterns (Nighttime vs. Daytime Usage)

Comparing two scenarios of using a portable AC unit with a cooling capacity of 12,000 BTUs and an EER of 9, but with different usage patterns:

Daytime Usage: The unit runs for 8 hours during the hot daytime hours. Daily Energy Consumption = 10.67 kWh (1,333 watts * 8 hours / 1,000).

Nighttime Usage: The unit runs for 6 hours during the cooler nighttime hours. Daily Energy Consumption = 8.0 kWh (1,333 watts * 6 hours / 1,000).

And this example tells us how adjusting usage patterns can impact daily energy consumption, as running the AC during cooler periods can be more efficient.

8 Tips to Save Electricity 

  1. Right Size Matters: Choose a portable AC that matches your room size. A unit that’s too big wastes energy, while one that’s too small works harder.
  1. EER Check: Pick a model with a high Energy Efficiency Ratio (EER). A higher EER means better cooling with less electricity.
  1. Seal Leaks: Seal gaps around windows and doors to keep cool air in. This helps the AC work more efficiently.
  1. Keep It Clean: Regularly clean the AC’s filters and vents. Dirty filters make the AC work harder, using more power.
  1. Smart Placement: Put the AC in a shady spot near a window. Direct sunlight heats up the AC and makes it work harder.
  1. Set Temperature Wisely: Set the thermostat to a comfortable but not too chilly temperature. Every degree lower uses more energy.
  1. Timed Cooling: Use a timer or programmable settings to avoid running the AC when you don’t need it, like at night or when you’re out.
  1. Cover Windows: Hang curtains or custom fit blinds to block out heat from the sun. This reduces the workload on the AC.


As we wrap up our exploration into the world of portable air conditioners and their electricity usage, it’s clear that understanding how much energy these units consume is very important. 

We’ve learned that several factors influence their electricity consumption, such as cooling capacity, energy efficiency ratio (EER), room size, and climate you are in.

Remember, it’s not just about the initial cost of the unit, thinking about long-term energy savings and environmental impact is equally important.

Now that you have this new knowledge, you can confidently and responsibly manage your cooling needs by purchasing a suitable portable AC.

Be environmentally conscious and remember that each degree matters!

Shashank Sharma
Shashank is a tech expert and writer with over 8 years of experience. His passion for helping people in all aspects of technology shines through his work. He is also the author of the book "iSolution," designed to assist iPhone users. Shashank has completed his master's in business administration, but his heart lies in technology & Gadgets.

How to Grow Your YouTube Channel through Packages Quickly

Previous article

Guide: How to Share Apple AirTag tracking with Police on iPhone

Next article

You may also like

More in Tech