Portable air conditioners use an average of 1,176 watts per hour. This power rating greatly varies depending on the unit’s model. Still, you can gauge the electricity usage based on its size. Larger models generally require more electricity to run. However, other factors like standby time and startup power consumption can affect electricity usage.
Keep reading to learn more about how much electricity your portable air conditioner unit needs.Â
Average Wattage of a Portable Air Conditioner
The amount of electricity used by portable air conditioners depends on the size of the unit.
The wattage of portable air conditioning units refers to their power rating. It is the maximum amount of watts that the device will consume. The manufacturer of the portable air conditioner model calculates the power rating. However, this number does not consider standby power consumption, startup power consumption, and prolonged usage periods.

Portable air conditioners use an average of 1,176 watts per hour (1.176 kWh).
Different models and sizes of portable air conditioning units have different electricity usage rates. Overall, the average electricity consumed by each unit size is as follows:
- Compact portable air conditioners: 500 to 900 watts per hour (0.5 to 0.9 kWh)
- Mid-range portable air conditioners: 2900 watts per hour (2.9 kWh)
- Large portable air conditioners: 4100 watts per hour (4.1 kWh)
Portable air conditioners on the market are usually on a smaller scale. You can easily find small to mid-range units that average 940 to 1,650 watts per hour (0.94 to 1.65 kWh).
Turned-off portable air conditioners still consume electricity in standby mode.
Standby mode is when appliances still consume electricity when turned off yet plugged into an outlet. This happens when the device has keep-alive circuitry like LED displays and timers. In those cases, a dedicated power supply is needed, which continues to consume electricity. For portable air conditioners, standby mode typically consumes 1 to 6 watts per hour.
Other factors not usually measured are startup power consumption and prolonged usage.
Portable air conditioners can experience power surges during startup. Power surges are considerably higher than the manufacturer’s air conditioner watts. However, power surges only occur for a short time. Portable air conditioners tend to consume less electricity when used for prolonged periods.
You can accurately determine how much electricity a portable air conditioner use by checking the manufacturer’s manual included in your chosen model.Â
Energy Efficiency of Portable Air Conditioners
Portable air conditioners are known as energy-efficient AC units.
Portable air conditioners are great alternatives to simple electric fans and HVAC systems. You can install these mobile systems in most types of rooms. Also, they can be removed and replaced in other locations without special installation methods. The only requirement generally needed is a nearby window to vent hot air through.
The energy rating of portable air conditioners depends on their size.Â

Energy rating is determined by the amount of energy needed to cool a pound of water by one degree Fahrenheit. This is typically measured in BTU or British thermal units. Portable air conditioners are available in compact box sizes to larger, mini-fridge-sized ones. The portable air conditioner BTU is the amount of energy needed to cool down a certain room size. [1]
The average energy efficiency rating of different portable air conditioner units are as follows:
- Compact sizes (0.9 kWh consumption): 7,500 BTU per 150 square feet
- Mid-range sizes (2.9 kWh consumption): 10,000 BTU per 300 square feet
- Large sizes (4.1 kWh consumption): 14, 000 BTU per 500 square feet
Note that these energy efficiency ratings may not hold for your unit. Each manufacturer has a different electrical system for their portable air conditioner. Some efficient portable air conditioners consume less power, while others consume more.Â
Factors that Affect Energy Efficiency and Electricity Consumption
The following factors increase or decrease your unit’s required air conditioner watts.
Temperature Settings
The best way to maximize efficient portable air conditioners is to keep their temperature constant.
Lowering your temperature settings causes electricity usage to spike. Moreover, changing the temperature throughout the day can lead to upsurges and higher electricity usage.
Regular Maintenance
You should professionally service portable air conditioners at least two times per year.
Regular maintenance keeps the unit at its peak energy efficiency. You can perform simple maintenance routines like cleaning and changing air filters at home. Clean filters allow more airflow into the unit, thus allowing it to cool the room efficiently.Â

Regular checks for any damages to the unit are also advisable. You should immediately bring your portable air conditioner to a professional maintenance specialist if you notice water leaks or other damages.Â
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References
[1] BTU: What Does It Mean For You and Your Air Conditioner? – Trane – www.trane.com/residential/en/resources/glossary/what-is-btu/
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