Portable AC Energy Consumption And Running Costs Explained (2024)

• The energy consumptions of a portable AC largely depends upon its BTU capacity and energy efficiency rating.

• Portable ACs can in range BTU from 5,000 to 15,000 which translates to 1.4 kWh - 4.4 kWh in electricity consumption and about $174 - $1,210 running costs respectively.

• Units with higher energy rating use lower watts per BTU, but they have a higher upfront cost.

Most electric appliances I've reviewed meter their electricity consumption in kilowatt hour (kWh) rather than just watts (W).

This metric represents the total energy an appliance uses in an hour.

How much electricity a portable AC unit uses depends on diverse specifications, notably BTU ratings.

BTU (British Thermal Units) measures an air conditioner's energy usage, determining its cooling capacity within an hour.[1]

Portable air conditioners with unique specifications highlight the significant BTU rating in their models.

The initially overwhelming BTU discussions captivated my attention in my exploration of portable air conditioners.

Amidst my research, I was intrigued by the direct link between a unit's BTU rating and estimated electricity use (kWh).

I made a table illustrating this connection, including the yearly electricity cost for operating the unit.

Efficiency matters in a portable unit, and the overlooked factor is its efficiency rating.

Two key ratings for energy costs are EER (Energy Efficiency Ratio) and SEER (Seasonal Energy Efficiency Ratio).

My first-hand lesson came when I replaced my AC unit without checking the specs, leading to a noticeable spike in my electric bill.

What are EER and SEER?

EER measures cooling efficiency per watt-hour used, determining operating costs.

Higher EERs signify better efficiency and lower long-term operating costs.[2]

SEER is more detailed–it factors temperature variations over an entire cooling season.

A higher SEER in a portable air conditioner denotes better energy efficiency.

The US Department of Energy recommends a minimum SEER of 14 for northern and 15 for southern regions.[3]

Calculating the average consumption for portable ACs was easier than I thought. All I did was use the EER efficiency rating.

Let me do the math: A portable AC's wattage equals the BTU cooling capacity divided by the EER rating.

Besides kWh, BTUs, efficiency ratings, and wattages, I still had to figure out the cost of running a portable air conditioner.

Previously, I sketched out how a portable AC's BTU and efficiency affect hourly power consumption (kWh).

Here's the missing piece:

Multiply the portable air conditioner's maximum power by your local electricity cost per kWh.

To determine the daily expense, multiply the earlier findings by 8 operating hours of daily portable AC use across common BTU ratings.

The table below demonstrates the approximate expenses for different portable AC units:

Before investing in a home portable AC, ponder: How well can it cool, and what's the impact on my electricity bills?

Apart from the AC's cooling prowess, I would look at its operational cost and efficiency. When scouting for a portable AC, I used these pointers to find the perfect fit:

Like using a single ice cube for a tall glass, what's enough for a small room won't cut it for a large living room.

For a big single room, extra compressor workload and longer AC run times are necessary for effective cooling.

Note that most portable units shine in spaces around 300 to 500 square feet.

Exceeding that means more frequent AC cycles, leading to increased energy consumed (energy waste).

I'd align my portable air conditioner with the spaces' cooling demands.

I've touched on this before, but let me delve into BTUs' power impact.

Higher BTU ratings imply more cooling but often result in greater energy consumption. Buying a high-BTU unit for specific needs may lead to overkill.

And after running tests, I made these findings:

Oversized units cycle frequently, wasting energy in smaller spaces. Conversely, low-BTU units ran non-stop in a larger room but consumed more electricity.

The sweet spot is aligning BTU output with room size, around 20 BTUs per square foot.

I'd prioritize the efficiency rating when shopping for an energy-efficient portable AC.

Key metrics include EER (Energy Efficiency Ratio) and SEER (Seasonal Energy Efficiency Ratio).

Energy-efficient models boast the highest ratings.

A portable air conditioner with a higher EER or SEER uses less energy for the same BTU cooling output.

And it’s no surprise that Energy Star-certified portables don't waste power.

For example, a model with an EER of 13 demands half the energy of a unit with a 6.5 rating for the same cooling effect.

Regarding electricity costs, if you run a portable air conditioner with an EER of 6.6, it doubles your bills.

Despite the upfront cost, the long-term savings from an efficient model justify the investment.

I opt for units with an EER of at least 10, and I recommend you do the same.

During scorching days, my portable air conditioner labors to cool my entire house.

It's akin to running the LA marathon in 100-degree heat – the more direct sunlight, the more effort required.

Portable ACs wage the same thermal battle.

The temperature difference between the outside and inside forces the unit to work harder to pump out cool air.

In extremes, it may run continuously to reach the desired temperature.

What's the homeowner's takeaway?

Overall efficiency dips and electric bills hit an "all-time" high.

Yet, optimizing BTU capacity and efficiency ratings can curb consumption and can save money in the long run.

I didn't need Arctic-level cooling from all the portable ACs I hands-on reviewed. Unless penguins share your space, here's the scoop:

While you may keep your central air conditioning system set to 72F, setting your portable air conditioner between 75 and 78 degrees Fahrenheit is the sweet spot for energy savings. Going colder spikes actual energy usage significantly.

I'm not suggesting you endure heat, but lowering it by a few degrees still impacts your running costs.

I've noticed a rookie mistake: avoid blocking your portable AC's vents with furniture like your couch or bed.

While it's tempting to snuggle near the vent, it disrupts general airflow. Mini-splits offer targeted cooling.

I suggest this because the hot air portable ACs draw needs an escape route.

Trapped hot air forces the cooler to work harder, leading to high electricity consumption and bigger energy bills.

Saving money? Not this way.

I can't stress this enough: the "right" BTU amount depends on specific room dimensions.

Higher BTUs mean an energy-guzzling monster, while too few lead to inefficient cooling.

I suggest 20 BTUs per square foot as a baseline for optimal efficiency.

It pays off to geek out on energy metrics for portable AC units. I would focus on EER and SEER ratings before making a purchase.

And, no, I didn’t use complex formulas; simply remember that higher EER and SEER ratings mean less energy consumption.

And that results in less running costs when operating a portable air conditioner.

Consider Energy Star certifications as the gold standard—a recognition of genius efficiency.

To earn this approval, efficient portable air conditioners undergo rigorous lab tests, ensuring optimal cooling with minimal electricity use.

Think next-level efficiency with features like a programmable timer, smart thermostats, and eco modes, alongside impressive SEER and EER ratings.

Though pricier, units with a blue Energy Star label that I reviewed had stellar efficiency.

Appliance cleaning feels more like routine dental checks—not fun but essential.

Same as changing your car's oil filter, clearing debris from portable AC vents keeps it efficient.

Dust buildup strains motors, forcing the AC to overwork, which spikes energy bills.

I do regular maintenance on my portable AC at least once a month. The DIY fix includes cleaning the air filters and checking the exhaust hose for clogs.