Portable air conditioners are a total game changer — and yes, you totally need one.
Here's something Megan Thee Stallion won't tell you: Sometimes a Hot Girl Summer™ can get a little *too* hot. And unless you have access to a pool or plan on finding a Boat Friend, staying indoors is a must in extreme circumstances where the heat index(opens in a new tab) exceeds 100 degrees; dehydration, heat stroke, and heat exhaustion can strike after just 10 to 15 minutes of outdoor activity.
But what if it's just as sweltering inside your house as it is on your patio? Even with proper ventilation, a sun-baked living room can quickly turn into an oven on an average August day. In that case, experts recommend relying on something other than a fan(opens in a new tab) or an open fridge door(opens in a new tab) for your primary indoor cooling setup — namely, an air conditioner.
There's a good chance your home's already equipped with an A/C unit: The U.S. Energy Information Administration reported(opens in a new tab) last year that A/C equipment is used in 87 percent of households throughout the United States — a statistic that shoots up to 94 percent when you venture down into the hot-humid South. And whereas central A/C systems were once a luxury reserved for the 1 percent, they're now very common in new single-family homes; about 60 percent of U.S. households were using them as of 2015.
While many older houses and apartments have been "retrofitted" with central air, a good chunk of us — about one in four households — still depend on individual A/C units to cool a room or two. Those devices generally fall into one of three categories:
A wall or window air conditioner is an A/C unit that gets mounted inside — get this — a wall or window. Without going into too much jargon-y detail, the unit lowers a room's temperature by sucking the hot air inside of its system with a blower motor, then passing the air over a condenser or cooling coil containing a chemical refrigerant. The air is then blown out of the unit drier and a few degrees colder, leaving the room all nice and air conditioned and slightly dehumidified. The leftover heat extracted by its compressor is expelled via a vent on the side (on a wall-mounting unit) or back (on a window-mounting unit) of the device.
A portable air conditioner is a free-standing, rolling floor A/C unit that vents hot air out of an exhaust host connected to a window.
An evaporative cooler, also known as a "swamp cooler," is a device that cools air by adding humidity to it (as opposed to a traditional A/C unit, which acts as a dehumidifier). Once the warm air is drawn into the unit, it's pushed through water-soaked pads that turn it into a (chillier) gas via the process of evaporation.
Window- and wall-mounted machines are probably what came to mind when you read the phrase "individual A/C units" because they're everywhere — just walk outside in any city during the summer and you'll see them clinging to the sides of buildings (while dripping condensation on many a passerby). However, many modern living situations are better suited for a portable air conditioner or an evaporative cooler.
If you're not sure what kind you need, here's a quick primer:
You should install a window/wall air conditioner if: You need to save space inside a room; you only need to cool one room at a time; your home needs dehumidifying; or you want an Energy Star-certified unit. (More on that momentarily.)
You should install a portable unit if: You don't want to diminish the amount of natural light entering a room; you want/need to move your A/C unit frequently; you live in a humid area; you only need to cool one room at a time; you don't want to deal with a complicated installation process; your home needs dehumidifying; or if window-mounted units are prohibited by your lease or HOA.
You should install an evaporative cooler if: You live somewhere with a dry climate(opens in a new tab); you want a unit that runs naturally (i.e., without chemical refrigerants); you're on a budget; or you think exhaust hoses are unsightly.
If a portable A/C or evaporative cooler sounds like the best air conditioning option for you, keep reading for a brief buying guide.
How to shop for a portable air conditioner or evaporative cooler:
Let's start with the more straightforward of the pair: evaporative coolers. Inside every unit, there will be a blower motor or fan and a handful of pads that absorb water from a built-in tank or reservoir, which you'll have to fill every once in a while. (Pro tip: Use ice water for an extra-cold chill.) Each model will have a cubic feet per minute (CFM) rating, which indicates how much air it moves every 60 seconds; the higher the CFM rating, the more powerful the unit. Whichever size or model you choose, the device should be run in a room where a window or two is cracked to prevent the space from getting too damp.
Moral of the story: The higher a unit's BTU, the more space it can chill and the faster it can chill said space.
Whereas there's just one kind of evaporative cooler, portable air conditioners are available in two different exhaust hose configurations: single hose and dual hose.
Single-hose units have only one exhaust hose (duh), which expels both the heat produced by the compressor and the indoor air its system pulls in to cool said compressor. They're typically cheaper and lighter compared to dual-hose units, but there's a catch: Their design creates negative air pressure inside of a room, causing warm air from the outside or nearby rooms to seep under doors and through window gaps. As a result, they're not very efficient and have to work harder than their dual-hose counterparts to cool a room.
Dual-hose units have — you guessed it — two exhaust hoses: one that vents hot air, and one that pulls in cool air from outdoors to prevent the compressor from overheating. Any air that's sucked in from a room gets put back in said room, making negative air pressure a non-issue and more effectively chilling an enclosed space.
Whether you opt for a single- or dual-hose unit, it'll likely come with a window kit for installation. Many machines will have a built-in pan, bucket, or tray to collect condensation, which you'll need to empty occasionally, although some newer units feature self-evaporating systems that recycle the moisture they produce. (Very rarely will you come across a unit with a drain pump.) Both single- and dual-hose units should be used only when your windows are closed.
Lastly (but perhaps most importantly), be sure to keep in mind the acronym "BTU" while you're hunting down the right portable air conditioner. (That stands for "British thermal unit," which is the amount of heat necessary to heat a pound of water by 1 degree Fahrenheit.) In the simplest sense, an air conditioner's BTU indicates how much energy it's capable of processing in an hour, i.e. its cooling power. Moral of the story: The higher a unit's BTU, the more space it can chill and the faster it can chill said space.
Are portable air conditioners eco-friendly?
At the time of publication, no portable air conditioners have been certified as Energy Star(opens in a new tab) by the Environmental Protection Agency — so unfortunately, no. But you can take certain measures while running your portable A/C to make sure you don't single-handedly trigger a climate catastrophe (on top of the one that's already in full swing), like buying a unit with a programmer timer that shuts it off when you're not home. For eco-friendly window and wall units, check out this roundup we put together.
What is the best portable air conditioner?
We generally recommend portable air conditioners for the best cooling power, but there's a time and place for an evaporative cooler, too. Below, you'll find our top picks based on online reviews written by the people who know the units best: actual customers who have installed them in their homes.
