If you've ever installed a window air conditioner, you know it's a hassle. These beasts can weigh over 100 pounds, and there's always the fear it could fall out and squash someone below. You may be tempted to get the nicer-sounding portable air conditioner. Yet, after testing more than 30 portable and window units for our best air conditioner guide, I strongly recommend choosing a window AC if your living space will accommodate one.
If you don't know which type to get, I break it down below, looking at the most important factors and use cases, considering elements like convenience, cooling performance, energy efficiency and costs. Check out our guides to the best portable air conditioners and window units if you want specific recommendations. Spoiler: here are the top picks from each guide:
Quick comparison
| Window AC | Portable AC | |
| Installation | Takes 25-35 minutes, can be cumbersome, only fits specific window types | Fairly quick process (10-15 minutes), will fit most windows and openings |
| Cooling Performance | Cools more than twice as quickly as portable | Doesn't cool as well due to design |
| Energy Efficiency | Uses 0.43 kWh per hour on average | Uses 0.88 kWh per hour on average: twice as much |
| Cost | Lower upfront and recurring costs | Typically, more expensive upfront and to operate |
Installation and convenience
Installing a window air conditioner is a pain. You will likely need a screwdriver, level, pencil, and drill. You'll need to lift the heavy AC, position it correctly in your window, and ensure it's secure. I've tested 13 air conditioners, and on average, they take 25 to 35 minutes to install.
Window air conditioners only fit specific windows: single- and double-hung windows. If your window is narrower than 22 inches wide, most window ACs won't work. You also need a vertical clearance of at least 14 inches. Once the unit is installed, you can't open and close your window to let fresh air in.
On the other hand, setting up and removing a portable air conditioner is easy. The initial installation takes 10 to 15 minutes on average. You just remove the AC from the box; roll it where you want it; attach the hose and window slider, adjusted to fit your window; and you're ready to plug it in and start cooling. If you want to move the portable AC, it only takes a minute or two to uninstall and reinstall it in another room. Window units take much longer.
To vent a portable AC's hot air, you only need an opening as wide as the exhaust hose, about 4 or 5 inches. Consequently, portable ACs fit a wide range of window styles and sizes. Since they're easy to uninstall, you can effortlessly open and close your window.
Performance
We test portable ACs by running them in a 550-square-foot room for two hours to see how much they lower the room's temperature. We run window ACs in a 650-square-foot space for just an hour.
We test portable ACs in a smaller room because they are generally rated to cool smaller areas, and the room's windows don't support window units. We test portable units longer because we noticed they take longer to reach a plateau where they no longer decrease the room's temperature.
Since the portable ACs run for longer in a smaller room, you'd expect a more significant temp drop. This is not the case. On average, the portable units decreased the room temp by 2.5 degrees Fahrenheit over two hours. The window units dropped the temp 2.6 degrees in one hour.
The difference in performance can be attributed to how the hot air is removed. Window air conditioners are mostly situated outside, and the hot air is sucked directly out of the room. Portable units rely on an exhaust hose to get the hot air from the AC to the outdoors. Much of the heat escapes from the poorly insulated hose back into the room before it can make it outside.
Window air conditioners were also quieter than portable air units on average, though the difference was only two decibels.
Energy efficiency
We used smart plugs to measure how many kilowatt-hours (kWh) of electricity the ACs consumed during testing. On average, window units used 0.43 kWh. Portable ACs used more than twice as much, 0.88 kWh, in the same period.
As mentioned above, portable units are inherently less efficient since much of the heat they remove from the room ends up back in the room as it escapes from the poorly insulated exhaust hose before it makes it outside. Window ACs don't have this problem since the hot air is released directly outside.
Cost
First, let's consider the long-term energy costs. As mentioned in the previous section, window ACs use half as much energy as portable units, which also translates into lower energy costs. Based on government estimates (16 cents per kWh, 8 hours of use per day, and 3 months of use) and our testing, a portable AC will cost you about $52 more to run each season than a window AC.
Window ACs also have a cheaper upfront cost. The median price of our portable AC pick is $510, yet only one of our window AC picks costs more than that.
Space requirements
While window air conditioners hang out of your window, portable ACs require floor space. Plus, to work effectively, you must leave plenty of room around the unit to allow airflow. This may be a dealbreaker for people in tight living quarters, where every square foot is precious.
The bottom line
When comparing products, it's rare to have such a cut-and-dried answer, but window air conditioners are superior to portable units in every area except installation and convenience. Get a window air conditioner if you have a single- or double-hung window. It will cost you less in energy costs and will do a better job of cooling.
Still, a portable AC is a satisfactory alternative if you don't want to install and uninstall a window AC every year or if you don't have a window that will support a window unit.
What are the best portable and window air conditioners?
We tested 14 of the best portable air conditioners for our guide to the best portable air conditioner, and the Midea Duo Smart Inverter Portable Air Conditioner came out on top. It was among the best at operating quietly and cooling the test room. Plus, it was easy to install and has a feature-packed app.
The Midea Duo Smart Inverter Portable Air Conditioner has a feature-rich app that pairs with Amazon Alexa and Google Assistant for voice control, and it does an outstanding job of cooling while operating quietly.
What we like
What we don't like
For our best air conditioner guide, we tested 18 models, and the Midea U-Shaped Window Air Conditioner came in first because of its balance of energy efficiency and cooling performance. It's unique U-shaped design allows you to open your window while it's installed.
The Midea U Inverter Window Air Conditioner features a unique design that lets you leave the window open while it's installed. While it was recalled last year due to mold concerns, the new 2026 version (MAW08V1UWT) addresses those issues with new drain plugs and external levelers.
What we like
What we don't like
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