If it’s the middle of summer and you need a new AC unit, we’re here to compare a portable air conditioner vs a window AC. Although both ‌devices offer several benefits, you want the best air conditioner that will fit your needs if you’re considering these two models. Read on to find out the differences between the two devices and their uses. If you want a more permanent solution, consider using a room air conditioner vs central air conditioning.


  • Portable units cool any room you put them in, even if there are no windows.
  • A window air conditioner cools better and uses less energy, but you must vent it through a window.
  • If you’re on a budget, ‌choose a window unit because they are less expensive and use less energy.

Comparing a Portable AC with a Window AC

With so many air conditioner models on the market, it can be hard to determine which is best for you and your home. Still, the portable model and window models provide excellent options for cooling a room. These two types of air conditioners have different uses, efficiencies, and costs.

Insider Tip

A window unit may help you save floor space.

As a result, you may be confused about which to purchase, but you can compare each using the information below. For more technical details on various ACs, check out packaged terminal air conditioner vs mini-split.


Portable air conditioners (PACs) are easily moved and used within multiple rooms of your house or office, as the name suggests. Because these devices do not have to be screwed into your window sill, the appliance is not limited to one location. There are few restrictions on using PACs in apartments, so you can use one regardless of where you live. For example, you will need to place the portable air conditioner unit near a window space for the exhaust hose to vent the air properly. However, if you are low on living space, portable AC units take up more room than a window model with smaller sizes. But, compare an evaporative air cooler vs a portable air conditioner before you make a buying decision. You will also need to empty a drain pan for some models or be left wondering, why is my portable air conditioner leaking water. We also have a great article on what to do if your AC sounds like running water.

On the other hand, window AC units must be used in rooms with at least one window frame because they rely on air intake from outside. Additionally, you risk damaging your windows if you don’t properly attach the unit to the window sill with screws through drilled holes during installation. Some apartments don’t allow window ACs because of this requirement. You also have to unscrew the unit if you want to move it to another room. That said, compare a window unit vs an in-wall air conditioner to find a better alternative.


A window air conditioner provides ventilation for warm air in your room by releasing the condensate outside through the hose while cooling the air as it passes through the unit and vent. The air flows inside and mitigates any ‌pressure differences between the cooled air and warmer air. Finally, window ACs are more energy-efficient, reducing your energy footprint.

PACs only cool air near the system, causing a difference in temperature within your house. As a result, you may encounter warm spots and lowered efficiency when warm air is pulled into the cooled space. These units typically have more energy usage to cool the same amount of air as a window AC, and they have to run more frequently as the warm air infiltrates the cooled area. To learn more, you can read our page on how portable ACs work as well as how much wattage a portable AC uses if you are interested.


PACs typically cost more than window models both to purchase and run. This difference is partly because of the lower British Thermal Unit (BTU) rating, which measures the time and energy used.

Window ACs have higher BTU ratings and lower cooling times for the same space. This variation reduces the cost required to run the system each time you use it. Window ACs are also generally cheaper to purchase initially.


Some apartments do not allow window units, so you might want a portable AC if you live in that setting.


How many BTUs do you need?

You should have about 20 BTUs per square foot.

What’s with the different DOE ratings on performance and energy?

A window air conditioner cools better and uses less energy, but you must vent it through a window.

How many watts does a window AC use?

The average window unit uses about 500-1,400 watts per hour.

STAT: In energy guides, the estimated annual energy cost represents running your AC for about eight hours per day for 90 days. (source)

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