Last updated: February 24, 2024.
How many watts does a portable AC use? Find out here and see the most energy efficient portable air conditioners by room size. Plus, see the lowest wattage portable air conditioner in the study.
Based on a study of 56 of the most popular models (updated for 2024), in this article you’ll get portable air conditioner wattage results, power consumption details, energy efficiency insights, and more.
- Portable AC wattage ranges from 754W to 1480W, with 1250W being the most common. A power consumption test reveals the low wattage portable AC unit’s actual draw is 725W;
- Non-standard, less popular, less efficient models can draw as little as 340W, to a high of 4000W. Personal coolers, not captured in this study, can draw just 7W;
- On average, based on the data, standard portable air conditioners use 1.176 kWh of electricity per hour;
- Portable air conditioners are suitable for room sizes that are 775 sq. ft. or smaller;
- Portable AC units have an average BTU of 11,464, an average EER of 9, and an average CEER of 7.5; and
- The most energy efficient portable air conditioner has an EER of 12.2.
Continue reading to see the most energy efficient portable air conditioners by room size.
Plus, estimate how much energy your unit consumes with the helpful Portable AC Electricity Usage Calculator, below.
- Portable AC wattage
- How much electricity does a portable AC use? (In kWh)
- Portable air conditioner energy efficiency
- Energy efficient portable air conditioners
- Final thoughts
Portable AC wattage
Portable AC wattage ranges from 754W to 1480W, with 1175.66W being the average and 1250W being the most common wattage.
This is based on 56 of the most popular portable air conditioners on the market.
|Portable AC Wattage Category
There are outliers to this wattage range. For example, personal air coolers are considered by many to be air conditioners. These devices can have a listed wattage of just 7W.
In this article however, portable air conditioners are considered to be AC units that are similar to window and wall air conditioners, but with wheels.
Portable AC wattage refers to the power rating of the device. In other words, it’s the manufacturer’s listed wattage – this is generally the maximum amount of watts that the device will consume.
However, this doesn’t take into account startup surges in power, standby power consumption or electricity usage over longer periods of time.
So next, let’s take a look at how many watts portable air conditioners use across various stages of operation and durations.
How many watts does a portable AC use?
On average, portable air conditioners have a power rating of 1175.66W, but consume an estimated 1050W while running at max draw, nearly 1500W on startup and 1W in standby mode.
Portable air conditioners can continue to consume electricity while off but still plugged in.
In standby mode, portable air conditioners typically use between 1W and 6W.
While running at their peak power consumption, portable air conditioners consume slightly less than their power rating.
For example, Amazon’s choice for “energy efficient portable air conditioner” uses approx. 20% less than its power rating while running – check it out, here.
However, during startup these units can experience power surges that are considerably higher than their power rating.
For those running their portable AC units off of batteries or generators, many suggest doubling the device’s power rating to be on the safe side when estimating how many watts will be drawn during startup power surges.
Before we take a look at how much electricity portable AC units use over time, let’s take a look at low wattage portable air conditioners.
Low wattage portable air conditioner
Low wattage portable air conditioners have a power rating of 850W or less.
Medium wattage portable AC units have a power rating of 851W to 1199W, while 1200W+ is considered high.
Low wattage portable AC units typically cater to smaller spaces compared to their medium and high wattage counterparts.
Having a low wattage does not mean that the unit is energy efficient.
A portable air conditioner that has a low wattage just means that it consumes a relatively low amount of power to operate. It may, however, not be as effective at cooling compared to its counterparts.
EER, CEER and BTU along with wattage are key indicators of energy efficiency – more on this below.
Low wattage portable AC units are great for RVs and smaller rooms (approx. 150 sq. ft.).
Next, let’s take a look at how much electricity portable AC units consume over various periods of time.
How much electricity does a portable AC use? (In kWh)
A portable AC uses 1.176 kWh of electricity per hour, 9.41 kWh per day and 35.27 kWh per month, on average.
This assumes that the device runs at its listed power rating for 8 hrs per day.
Out of the 56 models in the study, the most common electricity usage of portable air conditioners is 1.25 kWh per hour, 10 kWh per day and 37.5 kWh per month.
Overall, portable AC units consume between 0.754 kWh and 1.48 kWh of electricity per hour, 6.03 kWh to 11.84 kWh per day and 22.62 kWh to 44.4 kWh per month.
Related: see how much it costs to run a portable air conditioner. Spoiler: $0.11 to $0.22 per hour, with $0.18 being the average and $0.19 being the most common.
The table below summarizes how much electricity portable air conditioners use across various durations.
|Portable AC Power Usage Category
|Usage per hour
|Usage per day (8 hrs)
|Usage per month (8 hrs p/d for 30 days)
But how about your unit, how much electricity does it consume?
Estimate your portable AC’s power consumption with this helpful calculator…
Portable AC electricity usage calculator
Use this portable AC electricity usage calculator to estimate the power consumption of your unit per hour, day, week, month, and year.
Enter your portable air conditioner wattage (or actual consumption, if known) and how long you use it per day.
Using your unit’s wattage, which can be found on the back of your AC, will show the maximum expected power consumption under normal operating conditions. However, using test results for the typical draw will deliver a more accurate estimate, but this info is not readily available.
This calculator is pre-populated with an assumed usage of 8 hours per day, along with the most common portable air conditioner wattage.
The calculated results assume a continuous steady draw throughout operation.
Now that we know how much electricity a portable air conditioner uses, let’s add some perspective.
Do portable air conditioners use a lot of electricity?
Yes, portable air conditioners use a lot of electricity.
They are considered energy guzzlers.
For perspective, on average, running a portable air conditioner for 1 hour accounts for over 4% of the daily electricity consumption of a typical US household.
4% may not seem like a lot, but it’s a lot more than other household appliances.
Let’s add some more perspective by comparing the electricity usage of portable air conditioners with the electricity usage of common household appliances.
Running a portable air conditioner for 1 hour consumes 1.176 kWh of electricity. That’s equivalent to:
- How much electricity a TV uses after running for over 20 hours straight;
- How much electricity a ceiling fan uses after running for over 1.5 days; or
- How much electricity a freezer uses after running for close to 1 day.
Portable air conditioners consume slightly less electricity than electric heaters, which are notoriously power hungry.
So, yes, portable AC units use a lot of electricity.
As a result, it’s important to ensure you use an energy efficient model.
But before jumping into the standout energy efficient portable AC units, let’s look at the key performance indicators.
Portable air conditioner energy efficiency
Key energy efficiency factors for portable air conditioners are BTU, room size, CEER, EER and power consumption.
In order to get a good sense of portable AC energy efficiency and to provide a benchmark on performance, it’s important to understand these efficiency factors and have a benchmark on performance.
Below you’ll get a brief description of these factors along with performance benchmarks based on 56 of the most popular portable air conditioners.
Portable air conditioner BTU
Portable air conditioner BTU is a measurement of cooling power. In other words, it’s the cooling capacity of the unit.
BTU, which stands for British Thermal Unit, is a unit of heat. It’s commonly used when referring to temperature increases.
In the case of portable air conditioners, BTU refers to the amount of heat that the unit can remove from the air in one hour.
The higher the BTU for AC units, the higher the cooling capacity.
Portable air conditioners list one or even two BTU cooling ratings: ASHRAE and DOE SACC (also referred to as SACC or simply DOE).
ASHRAE (defined by the American Society of Heating, Refrigerating and Air-Conditioning Engineers) and SACC (Seasonally Adjusted Cooling Capacity, defined by the Department of Energy) are both cooling rating methods.
Without going into too much detail on each of these methods, the key points of note are:
- The difference between ASHRAE and SACC ratings is due to the different test procedures;
- ASHRAE BTU figures are higher than SACC;
- SACC was introduced after ASHRAE; and
- You should compare cooling capacities using only one of these methods.
It’s common to see older portable AC units and eCommerce websites only list ASHRAE ratings.
Portable air conditioner BTU (ASHRAE) ranges from 6,000 to 14,000, with 11,464 being the average and 14,000 being the most common.
These figures are based on the ASHRAE ratings in the study of 56 of the most popular portable AC units.
The table below summarizes the portable air conditioner BTU results from the study.
|Portable AC BTU Category
Units with higher than average cooling capacity are recommended for use in larger rooms.
Room size is a key energy efficiency consideration, so let’s briefly look at this next.
Portable air conditioner room size
Room size is a crucial energy efficiency consideration when it comes to portable air conditioners.
Portable air conditioners are suitable for room sizes that are 775 sq. ft. or smaller.
Overpowered portable AC units consume more electricity than necessary when cooling a space. And, on the other hand, underpowered units won’t effectively cool a large space.
As a result, it’s important to match the portable AC unit to the appropriate room size.
Continue reading to see the most energy efficient portable air conditioners by room size.
Portable AC manufacturers and retailers list the largest appropriate room size (also referred to as cooling area) for the device.
Portable air conditioner room sizes range from 150 sq. ft. to 775 sq. ft., with 397 sq. ft. being the average and 500 sq. ft. being the most common.
The table below summarizes the recommended room size results from the study of 56 different portable AC units.
|Portable AC Size Category
|Room size / cooling area (square feet)
|397 sq. ft.
|500 sq. ft.
|775 sq. ft.
|150 sq. ft.
So, if you’re looking for an air conditioner for a large room (over 775 sq. ft.) then a window air conditioner will likely be a better fit for you.
Related: check out this Window AC Room Size Chart to see window AC room sizes / cooling areas.
If the manufacturer or retailer doesn’t list the recommended room size, the unit’s BTU can be used to estimate the appropriate room size.
Additional factors such as how much sunlight the room gets, how many widows there are and how high the ceilings are, etc., should be considered in your estimate.
The portable air conditioner room size chart below, from Honeywell, will help you match BTU to room size.
Portable air conditioner SEER
SEER, which stands for Seasonal Energy Efficiency Ratio, is a common energy efficiency measurement.
Portable air conditioner SEER is found by dividing the cooling ability of an air conditioner during the warmer months by its power consumption.
Related – if you’re interested in an appliance that combines both heating and cooling functionality, check out the insights from this energy efficiency study: Highest SEER Heat Pump Revealed [2,126 Units Studied].
However, SEER is not as commonly listed for portable air conditioners – it’s much more readily available for window and wall air conditioners.
EER and CEER figures are more commonly listed for portable AC units, so let’s take a look at these next, including the results from the study.
Portable air conditioner EER
Portable air conditioner EER, which stands for Energy Efficiency Ratio, is a common energy efficiency measurement.
EER is calculated by dividing the portable air conditioner’s cooling capacity (in BTU) by its average power consumption (in watts).
Portable air conditioner EER ranges from 1.58 to 12.2, with 9 being the average and 9.7 being the most common.
The table below summarizes EER figures for 56 of the most popular portable air conditioners.
|Portable AC EER Category
|Energy Efficiency Ratio (EER)
EER does not take into account standby or off mode. However, CEER does.
So, let’s take a look at this next.
Portable AC CEER
Portable air conditioner CEER, which stands for Combined Energy Efficiency Ratio, is an energy efficiency measurement.
CEER is calculated by dividing the cooling capacity (in BTU) by the average power consumption (in watts) during on and off modes.
CEER, unlike EER, combines on and off / standby modes to get a more accurate assessment of energy efficiency.
Portable AC CEER ranges from 1.58 to 14.7, with 7.5 being the average and 7.9 being the most common.
The table below summarizes CEER figures from the study of 56 portable air conditioners. However, please note that CEER figures were reported considerably less than EER figures and it’s unclear that online retailers accurately report CEER figures – there may be confusion between CEER and EER.
|Portable AC CEER Category
|Combined Energy Efficiency Ratio (CEER)
Related: see how Portable AC CEER compares with window AC CEER, check out Window AC vs Portable AC.
So now that we have an understanding of the key energy efficiency indicators for portable air conditioners, let’s see which models stood out most from the study.
Energy efficient portable air conditioners
Energy efficient portable air conditioners are those that have the lowest power consumption that also deliver enough cooling to meet the user’s needs.
As a result, the portable air conditioner with the highest CEER rating for your room size will, in general, be the most efficient option for you.
If CEER is not available, then EER ratings should be used.
Other factors come into play too.
In addition to the factors mentioned above (e.g. ceiling height), portable air conditioner features (e.g. number of cooling settings, dual hose) and user preferences (e.g. a desire to rapidly cool the space) have an impact.
For simplicity, however, let’s remove subjectivity and stick with the data (specifically CEER, EEF and room size).
Portable air conditioners are not ENERGY STAR certified so data from manufacturers is used.
The table below lists the most energy efficient portable air conditioners by room size, based on the study of 56 of the most popular units on the market. Also included are links to online retailers so you can see if the appliance meets your own specific needs and preferences.
|Most efficient portable air conditioner
|Links for more details
|CEER or EER
|150 sq. ft.
|BLACK+DECKER 5,000 BTU (SACC) Portable Air Conditioner, 8,500 BTU (ASHRAE); Model# BPT05WTBA
|Also the lowest wattage & amp draw in the study.
|250 sq. ft.
|KingHome 10,000 BTU (6,000 BTU DOE) Portable Air Conditioner; Model# KHPA06AK
|Also acts as a dehumidifier.
|350 sq. ft.
|GE 8,000 BTU (DOE SACC) / 12,000 BTU (ASHRAE) Portable Air Conditioner with Dehumidifier; Model# APCD08JALW
|Offers automatic even air flow distribution.
|400 sq. ft.
|Whynter Elite 12,000 BTU Portable Air Conditioner with Heat/Drain Pump & Dehumidifier; Model# ARC-122DHP
|Dual hose, more eco-friendly refrigerant, thermostatic controls.
|450 sq. ft.
|Honeywell 10,000 BTU Portable Air Conditioner with Dehumidifier & Fan. Model# HJ0CESWK7
|Low noise level at 49 decibels.
|500 sq. ft.
|NewAir 14,000 BTU (8,600 DOE) Portable Air Conditioner & Heater; Model# AC-14100H
|14.7 CEER (9.88 EER)
|Automatically maintains ideal temperature, eco-friendly refrigerant.
|550 sq. ft.
|DOLCECLIMA 14,000 BTU Portable Air Conditioner (4 in 1); Model# 2149
|9.3 CEER (9.9 EER)
|“Follow me” Mode to adjust cooling for desired area.
|600 sq. ft.
|FRIGIDAIRE GALLERY 13,000 BTU Portable Air Conditioner with Wi-Fi Control; Model# GHPC132AB1
|7.2 CEER (10 EER)
|Can control from anywhere via an app, works with Alexa too.
|700+ sq. ft.
|Honeywell 775 Sq. Ft. Portable Air Conditioner with Dehumidifier & Fan. Model# HJ5CESWK0
|Good EER but customer reviews are not great.
Now that we know which portable air conditioners stood out, in terms of energy efficiency, let’s take a look at the most energy efficient model overall.
Most energy efficient portable air conditioner
The most energy efficient portable air conditioner, in general, is the 980W, 400 sq. ft., dual hose, Whynter Elite ARC-122DHP.
See the features and price, here.
This model is the standout all-rounder.
It’s efficient, powerful and versatile. It also has some great reviews on various eCommerce websites.
Some of its key features are:
- It can act as a dehumidifier, heater and fan, in addition to being an AC unit;
- It uses a more eco-friendly, CFC free, green R-410A refrigerant; and
- It has a cooling and heating thermostat – temperature automation helps cut down on energy wastage.
It’s EER is 12.2 – the highest EER in the study.
However, there is one portable AC unit that requires an honorable mention due to its CEER.
With a CEER of 14.7, according to Home Depot, the NewAir AC-14100H must get a shoutout.
Check it out, including the price, here.
This powerful portable air conditioner and heater cools rooms up to 500 sq. ft., delivering 14,000 BTU – the highest recorded in the study.
With a 1420W power rating, this model is one of the more power hungry units.
Its EEF of 9.88 is not as high as the most energy efficient portable air conditioner. But, due to varying user needs and preferences, there are cases where this unit will be the most energy efficient.
As mentioned, many factors come into play when identifying the most efficient AC unit.
User needs (e.g. room size) and preferences (e.g. rapid cooling) means that the most energy efficient portable AC unit is not a “one-size-fits-all” subject.
Related: Are portable air conditioners quiet? [Quietest Revealed]
I hope that, by detailing the key energy efficiency factors and standout units by room size, you feel better equipped to find the most energy efficient portable air conditioner for you.
But did you know that portable AC units are not as energy efficient as other types of units? Stay tuned, I’ll go into detail about this shortly.
In the meantime, if you’re looking to reduce your electricity bills and carbon footprint, check out these 6 quick wins:
Choosing to go with a window or portable air conditioner is simple, when you have the data. Window vs portable AC – which is best? Find out here, based on data from comprehensive studies.
How much does it cost to run a portable air conditioner? Find out here. Also, get running costs of the lowest wattage & most efficient units. Plus, use this calculator to see your own specific costs.
How many amps does a portable air conditioner use? Find out here. Plus, get low amp portable AC details, see which unit has the lowest amp draw & see the amperage of the most efficient units.
James, Eco Cost Savings co-founder and Editor-in-Chief, is also our experienced in-house energy management and sustainability expert, and manager of our network of sustainability consultants.
Before his journey into sustainability, James studied engineering. Additionally, he has experience in HVAC installation, and data analysis. A self-proclaimed practical environmentalist, and avid penny pincher, James established Eco Cost Savings to share his and his colleague’s expertise with the aim of helping to reduce energy bills and carbon footprints at scale.