Portable Air Conditioners: How They Work And Our Top Picks

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When I lived in Florida, I rented a small home that had been built in the 60s. It had no central AC or heat, jalousie windows and a couple window air conditioner units that struggled to survive in the hot summers. I remember the catch buckets for the window units needed to be dumped twice a day, and it still never made a dent in the humidity (thanks to the inefficient windows that leaked any cool air that was generated).

After I moved, I then needed a portable air conditioner for my garage - my dogs used a doggy door for inside/outside access during the day - and it kept the area nice and cool. After sunbathing in the morning, they would sleep in front of the portable air conditioner unit before frolicking back out into the yard for their afternoon play.

Whatever your needs, if you’re in the market for a portable air conditioner, we’ve got a complete guide below. We kick it off with an explainer on how portable ACs work, the different options that are available, instructions on how to determine the proper BTU specifications, and finally, some of our top picks for the best selling and highest rated air conditioners on the market today.

What is a portable air conditioner and how do they work?

A portable air conditioner (also known as portable AC, room air conditioner or dehumidifier) is designed to be easily moved around the room, RV, boat, or campsite with wheels. Portable air conditioning units will cool the air through evaporator or cooling coils, compressors and condensers.

There are two main types of portable air conditioners:

1. Single-hose portable AC: Uses one hose for both air intake and exhaust, and while the generally cheaper option, it usually has to work much harder to cool the air. It pulls in air from inside the room, cools the air for circulation and vents the excess warm air out the window.
2. Dual-hose portable AC:Uses two hoses, one for air intake to circulate, and the other hose to expel the hot air and exhaust. It may also come with a single-air “return outlet” to circulate air faster. While more efficient and better for large rooms, it’s going to cost you more.

Do all portable air conditioners need to be vented out of a window?

Traditional air conditioners need venting, but not all portable air conditioners need to be vented out of a window. Here’s a helpful roundup of other venting options, like a sliding glass door, through a drop ceiling, dryer vent, and even a fireplace.

Sometimes you’ll find products that are branded as portable air conditioners, but they are actually evaporative air coolers (like this Dreo) that function more like fans and humidifiers, not a traditional refrigerant air conditioner.

Does a portable air conditioner need to be drained?

According to The Home Depot, most portable AC units will come with a vent kit, similar to a dryer, and will come stock with a water reservoir or will evaporate the moisture through an exhaust.

So technically, yes, all portable air conditioners need to be drained, it just depends on the method. Here are the main ways a portable air conditioner will drain the excess water:

1. Exhaust hose: Moisture and heat are blown out through the back of the unit via an exhaust hose, called automatic evaporation
2. Condensation tank (or water reservoir): Collects water dripping from the condenser coils and gathers in some type of collection pan. This will need to be manually emptied.
3. Drain hose: Some units allow you to attach a drain hose to the condensation tank to remove the water, so you can siphon the water into a more manageable container to empty

What is the best BTU measurement for portable air conditioners?

BTU

BTU, short for British Thermal Unit, is a unit of measurement for how much energy your air conditioner uses to remove heat from your home in an hour. The higher the BTU, the bigger the room size it can cool.

To start, calculate the square footage of the room by multiplying the room’s length by width (example 10 feet x 12 feet = 120 square feet).

There’s a more robust chart below, but at a glance, this is generally how your square footage will determine the BTU rating you need to cool the room properly.

• 250 sq. ft. – 8,000 BTU (ASHRAE)
• 350 sq. ft. – 10,000 BTU (ASHRAE)
• 450 sq. ft. – 12,000 BTU (ASHRAE)
• 550 sq. ft. – 14,000 BTU (ASHRAE)

Important buying tip: Buying too high of a BTU, and your portable air conditioner could cool too rapidly, turning off and on trying to control the temperature. But if you buy a BTU that is too low, the portable AC will use a lot more energy trying to keep the room cool.

ASHRAE Rating

Developed by the American Society of Heating, Refrigerating and Air-Conditioning Engineers, these testing conditions are done under ideal conditions for the air conditioner, but may not mirror real-life applications.

SACC Rating

Introduced by the Department of Energy (DOE), the Seasonally Adjusted Cooling Capacity (SACC) rating is a weighted average of a portable air conditioner’s performance at different temperatures and humidity levels.

Sylvane provides a great comparison chart of how ASHRAE versus SACC BTU’s can differ. Be sure to check out their website for more in-depth information on how the SACC is calculated.

Best Portable Air Conditioners of 2025

In the guide below, we’ll go into greater detail on each of our top picks in each category. We outline some of the main specs for each portable air conditioner, including BTU rating, room sizes, noise levels, product features and some common review feedback from buyers.

Update: We recently adjusted our large room recommendation following performance reviews and a drop in user rating. We’ve replaced it with a new offering in the list below.

Our Top Picks:

• Small Room Air Conditioner: SereneLife Small Air Conditioner Portable 8,000 BTU with Built-in Dehumidifier
• Medium Room Air Conditioner: Whynter ARC-14S 14,000 BTU (9,500 SACC) Dual Hose Portable Air Conditioner with Dehumidifier and Fan
• Large Room Air Conditioner: BLACK+DECKER Smart Portable Air Conditioner with Heat (14,000 BTU Cooling, 12,000 BTU Heating)
• Budget Air Conditioner: Pro Breeze 4-in-1 Portable Air Conditioner (10,000 BTU)
• Small Room Window Air Conditioner: Frigidaire FFRA051WAE Window-Mounted Room Air Conditioner
• Medium Room Window Air Conditioner: Midea 10,000 BTU U-Shaped Smart Inverter Window Air Conditioner

1. Best Small Room Air Conditioner: SereneLife Small Air Conditioner Portable 8,000 BTU with Built-in Dehumidifier

Shop It: Amazon, The Home Depot

Lowest Price: $349.90, was $399.99 at Amazon

• Even Better Sale: SereneLife Small Air Conditioner Portable 10,000 BTU with Built-in Dehumidifier

ASHRAE: 8,000 BTU | SACC: ~5,000 BTU | Room Size: Up to 250 sq. ft. | Weight: 45.8 lbs. | Noise: 55 dBA

Features:

• 3-in-1: Air conditioner, dehumidifier, and fan
• Removable and washable air filter
• LED display for time, temperature and fan speed; touch controls and remote
• 24-hour timer
• Comes with: Window vent kit, air exhaust hose

If you have a room between 150-250 square feet, the SereneLife portable air conditioner should be all the power you need to keep the room cool, with the dehumidifier and fan working in tandem to maintain the temperature. If you want to bump up the power, the SereneLife 10,000 BTU AC (~5,500 SACC) version is also an option, and has good reviews.

The dehumidifier can remove up to one liter per hour, according to the company specifications, and while the operating noise says its 55 dBA (A-weighted decibel), reviewers have noted it feels louder.

As one reviewer noted, "In regards to people complaining about noise- it is an air conditioner, - they all make noise. It is no louder than my previous window shaker. I would rather listen to the AC in coolness than sit in my hot apartment. This unit cools and cools fast. The fan on high is super powerful. It cooled 300 sq. ft. no problem."

Another reviewer said, “It’s a decent portable AC for the price…window sealing is the trickiest part of the whole installation process.” They went on to say that the installation manual could use a little work. This reviewer said, “We bought this product for my son’s room. He has a gaming computer that puts off a tremendous amount of heat. This unit turns his room into a frozen tundra. Great product!”

One of the most frequent complaints is that the window vent panel might not fit, and some said their air conditioner would randomly start to make loud noises. The longevity of the unit could be in question.

2. Best Medium Room Air Conditioner: Whynter ARC-14S 14,000 BTU (9,500 SACC) Dual Hose Portable Air Conditioner with Dehumidifier and Fan

Shop It: Amazon, Walmart

Lowest Price: $499.99 at Amazon; $674.25 at Walmart

ASHRAE: 14,000 BTU | SACC: 9,500 BTU | Room Size: Up to 400 sq. ft. | Weight: 73 lbs. | Noise: 51 dBA

Features:

• 3-in-1: Air conditioner, dehumidifier, and fan
• Dual hose evaporation
• Auto drain exhausts condensate automatically
• Dehumidifying capacity: 71 pints per day, according to company
• Temperature controls between 61 degrees to 89 degrees Fahrenheit
• Comes with: Window vent kit, (2) exhaust hose, remote control, storage bag

You may be wondering, why the significant jump between room sizes from small to medium air conditioners (plus, the BTU power is quite a leap), and it’s simply because we really struggled to find a sub-10,000 BTU that really did the trick. That’s why, we suggest scaling up to the Whynter ARC-14S 9,500 SACC Dual Hose Portable Air Conditioner to get the most bang for your buck.

According to the company, it can cool rooms up to 500 square feet, but we might suggest no more than 400 square feet depending on the ceiling size. Because of the dual hose evaporation, you shouldn’t need to worry too much about draining the unit like some of the others on this list, though there is a drain opening you can use with a hose. It’s quite a bit heavier than some of the other portable air conditioners, so it’s not going to be quite so easy to move around, and it’s fairly tall.

Many reviewers say this is a beast of an air conditioner, and can blow out extremely cold air. Multiple users had it in rooms with vaulted ceilings, and it was “up to the challenge.” One reviewer said, “At the end of the day, you just need the AC to do one thing: cool. And I think this thing has great performance, especially for a portable…the Whynter has kept my apartment 20 degrees cooler than the outside, on what I can only hope [was] the hottest day of the year.”

Another said, there’s “a lot to like with this unit”, going on to detail how well the dual hose works, the coldness of the air, auto-evaporates as promised and they said it runs quieter than some of the other portable air conditioners used in the past.

As for complaints, many mentioned that when the air conditioner reaches the desired temperature, the condenser will flip off and the fan will take over, but it can be quite jarring (especially if this is meant for a bedroom). Another mentioned the weight and difficulty in the initial set up, and others mentioned the customer service isn’t all that great if you have issues that need to be resolved.

3. Best Large Room Air Conditioner: BLACK+DECKER Smart Portable Air Conditioner with Heat (14,000 BTU Cooling, 12,000 BTU Heating)

Shop It: Amazon; Wayfair.com

• Budget option: BLACK+DECKER 12,000 BTU Portable Air Conditioner ($349, was $399)

ASHRAE: 14,000 BTU | SACC: 10,200 BTU | Room Size: Up to 550 sq. ft. | Weight: 63.6 lbs. | Noise: 52 dBA

Features:

• 4-in-1: Air conditioner, heater, dehumidifier, and fan
• Fits windows between 26.5-48.4 inches
• 24 hour timer, sleep mode with auto control, touch display
• Temperature range between 64 to 90 degrees Fahrenheit (cooling); 50 to 77 degrees (heating)
• Comes with: Window vent kit, exhaust hose, remote control

With an average 4-stars and over 5,500 reviews, if you need to cool (or heat) a large room, take a peek at the Black+Decker 14,000 BTU Portable Air Conditioner. While there are some slightly smaller Black+Decker air conditioners that are more budget-friendly, we appreciated the ‘all season’ option with both air conditioning and heating.

“Great unit when times get tough,” said one reviewer who needed a quick fix after the central air conditioning went out. Another said it “does pump out ice cold air”, though the hose that connects to the window can get hot.

A few called it “loud but effective”, said it “does the job” and that it kept reviewers cool when they needed immediate relief.

There are complaints, however, around the heating function, which doesn’t seem to do well in very cold conditions. Many noted it can be very loud, and two reviewers noted they only got around two to two-and-a-half years out of the unit before it stopped working.

4. Best Heat + Air Conditioner: SereneLife Small Air Conditioner Portable 10,000 BTU with Built-in Dehumidifier + Heat

Shop It: Amazon

Lowest Price: $379.99, was $556.99 at Amazon

ASHRAE: 10,000 BTU | SACC: ~6,000 BTU | Room Size: Up to 270 sq. ft. | Weight: 56.5 lbs. | Noise: 52-56 dBA

Features:

• 4-in-1: Air conditioner, dehumidifier, fan, and heater
• Sleep mode, touch button control, auto-swing mode, and timer
• Washable filter
• Comes with: Window vent kit, exhaust hose, remote control

We selected this SereneLife Portable Air Conditioner, with built-in dehumidifier and heater, as our best budget pick thanks to the four-in-one functionality and decently high reviews for the brand as a whole. If you don’t need the heating option, we suggest taking a look at the other SereneLife pick we selected for our small room option.

While we selected the 10,000 BTU as our default sizing option, there’s also a 12,000 BTU + Heat portable AC option that is currently available and on sale, with some solid reviews.

As with many other product picks on this list, there’s some tradeoffs – with a reasonable price point, many reviewers are pleased with the cooling performance, especially in a small to medium sized room. However, the window inserts aren’t easy to install with ill-fitting pieces, and the thermostat isn’t entirely accurate.

One helpful reviewer noted that the heater “blows some air after the pump is off like [a] central heating system” but that it may sometimes have a hard time distinguishing when to blow air and when to blow warm air, jumping back and forth.

5. Best Small Room Window Air Conditioner: Frigidaire FFRA051WAE (Manual) Window-Mounted Room Air Conditioner

Shop It: Amazon, Frigidaire, The Home Depot

Lowest Price: $169, was $179 at Amazon and $169 at The Home Depot

ASHRAE: 5,000 BTU | SACC: Not Available | Room Size: 150 sq. ft. | Weight: 35.3 lbs. | Noise: 52-55 dBA

Features:

• Air conditioner and fan
• Manual controls, auto restart
• Temperature range: 60 to 90 degrees Fahrenheit
• Comes with: Adjustable side panels, washable filter, power cord

When I lived in Florida, this Frigidaire Window Air Conditioner was the exact air conditioner I had in my bedroom. It was a small old house, and an especially small room. I would keep it on fan, low cool or even off (especially during the winter months) when I didn’t need it to run constantly. In the summer, I’d have it on high cool and the lowest setting before I went to bed, at which point I could manually set it a little lower to reduce the noise.

Don’t expect all the bells and whistles (or even a remote) for this price point, but according to my own experience, and the reviewers, you’ll get what you need out of this tiny little unit. Ideal for rooms sub-200 square feet, it’s going to be easy to install and simple to use.

One reviewer said, “This was probably one of the best AC units I have ever had. It was cheap and it works really well. The only problem I had was the back metal grate had dents in it. It cooled a whole room in just 20 minutes, and was very easy to use.”

Another called it a “reliable little guy”, while yet another said, “It is very powerful and easily cools a room down. Super cold, which I love. However, it is pretty loud.”

As for complaints, of which I can attest to as well, the window fitment is not the best. It’s not airtight unless you want to use some extra tools to make it a more seamless fit. Some felt the power wasn’t all high enough to properly cool their rooms, and it is loud despite the stated decibel level. Others received damaged packages when ordering from Amazon - you may wish to consider buying online and picking up in store from another retailer.

6. Best Medium-to-Large Room Window Air Conditioner: Midea 10,000 BTU U-Shaped Smart Inverter Window Air Conditioner

Shop It: Amazon

Lowest Price: starting at $440.75 at Amazon

ASHRAE: 10,000 BTU | SACC: Not Available | Room Size: Up to 350 sq. ft. | Weight: 56.9 lbs. | Noise: 42 dBA (lowest)

Features:

• 3-in-1: Air conditioner, dehumidifier, and fan
• MSmart home app, voice command works with Alexa and Google Assistant
• Auto, Eco and sleep modes; three fan speeds
• Temperature range: 60 to 90 degrees Fahrenheit
• Comes with: Window bracket, remote control
• Energy Star Certified

When it comes to window units, everything I’ve read points to the Midea (both 10,000 and 12,000 BTU options) as one of the best choices on the market. From the U-shaped design (which allows you to open your window for fresh air without uninstalling it), to the satisfied reviews, the Midea window units have a combined rating of 4.4-stars and over 20,000 ratings on Amazon.

Just looking at the reviews, users go into great detail on their experience with the Midea. One reviewer started off by saying it was better than expected, “It’s physically smaller than I expected, and the little platform thing that it sits on is genius…It’s far more quiet than a regular window unit, and when it’s on low, you can barely tell that it’s on.”

Another helpful person posted a video, and said, “I love the swinging blade at the top that allows the air to be circulated through the room.” One more called it the “best window AC on the market, but beware the install.”

As for complaints, installation seemed to be first and foremost the most difficult issue. Some reviewers said it wasn’t a problem, while others said it’s a two-person job. More users said it’s pretty loud despite the low decibel claims, and the customer service reviews were scathing when users needed to return the product.

How We Made Our Decision

First-hand testing

I try to do as much first-hand testing when possible, and I would only refer a product or service that has held up during use. One of our top picks included the Frigidaire small window unit because of my previous experience, as well as the incredibly low price point.

Safety

We researched a multitude of highly rated portable air conditioners, but if there are any instances of potential hazards, we will not include them from our list. In one instance during our research, a previously well-rated product had a review of a potential fire hazard.

Functionality

When pulling together our list of air conditioners (both portable and window units), we were looking at a few different performance criteria: BTU size (both ASHRAE and SACC), room size, noise levels, Wi-Fi or app programming, and preferably three-in-one functionality. We also visited EnergyStar.gov to cross check energy performance claims when applicable.

Price

Price point was one of our highlighted features in this roundup, and with a tight budget in mind, we wanted to highlight out which retailer has it for the cheapest price. Our goal was to keep it under $500 for the most popular options, though one of the higher BTU options crept up to the $600+ mark. Even the budget-friendly models should provide performance and have positive feedback.

Reviews

Reviews were highly important in this particular roundup without the extensive first-hand testing we would have liked to perform. We strive to highlight the unbiased pros and cons of each product based on user feedback and the feature list. If a product has few (or no) verified reviewers, or the complaints outweigh the purpose and price of the product, we won’t feature it in our lists. Portable air conditioner reviews were almost always an “all-or-nothing”, with some experiencing 4- to 5-star performance, while others would have preferred to throw it out of a window if possible.

Prices accurate and items in stock at time of publish.