In this Portable Air Conditioner Buying Guide, we first provide overview picks and full top portable air conditioner reviews. There are 10 models in different niches, so you can quickly choose one with the right size and/or features like WiFi or Heat that you want.
The best of the best: Our guarantee to you is that we have truly chosen models with the top ratings in their class, and we think that is unique to our list compared with others. We have no idea why other sites compile lists with poorly rated units.
The Buying Guide that follows is designed for you to research your options, compare portable air conditioners to window air conditioners and to central cooling options like a central AC, heat pump or mini split / ductless heat pump. Links throughout are available for exploring those other options, so you can make an air conditioning decision you will be happy with in the years ahead.
Quickly find the info you want with the Navigation list of topics, or read it all.
The Best Portable Air Conditioners: Quick Takes
Here are the 12 best portable air conditioners with bullet-point strengths.
The list allows you to quickly find a unit that’s right for your purposes, check the price and buy it if you’d like to, and get on with your day. Choose the links for further research on their product page too and to see what verified buyers have to say about each model.
Note on square foot coverage: We give square foot coverage estimates by on US DOE ratings, explained later. This give a more accurate idea of how many square feet the unit can serve. Most descriptions over-estimate coverage area.
Ivation 12,000 BTU
- Five Climate Control Modes
- LCD Panel & Remote Control
- Best in Class Features
- Evaporative Exhaust & Drain Hose
- Up to 350 square feet
Danby 6000 BTU
- Up to 150 square feet
- AC, Dehumidify and Fan-only
- Evaporate & Direct Drain Options
- Electronic Controls/Remote
- 10K, 12K & 14K BTU Models Too
For Small Room
LG LP0818WNR 8,000 BTU
- For about 200 square feet
- Bucket-free Evaporation
- Wide-range Oscillating Fan
- LED Control Panel/LCD Remote
- Oscillating louvers for balanced cooling
Best for Bedroom
JHS 10,000 BTU
- Up to 300 square feet
- Very Quiet 49-54 decibels
- Tank-Free Evaporation
- Makes Air Dry & Comfortable
- AC, Dehumidify, Fan Modes
For Medium Room
Quilo 14,000 BTU
- Best for up to 450 square feet
- Quietest 14K BTU Model
- Super-quiet Sleep Mode
For Large Room
- AC, Fan, Dry Modes
- No Drain Needed for AC
- Storage Bag Incl.
- Carbon Filter for Odors
- 3M Antimicrobial Filter
Best Dual Hose
RolliCool 12,000 BTU AC
- Best for 350 square feet
- WiFi & Alexa
- Quiet Operation
- AC/Dry/Heat Modes!
- 10K & 14K BTU Sizes too
Best with WiFi & Alexa
SereneLife 12,000 BTU
- Best for 350 square feet
- Top Quality
- Evaporative Condensation
- 3 Climate Control Modes
- Remote, 24hr Timer, More
SereneLife 12,000 BTU
- Up to 350 square feet
- Powerful Heating
- 4 Comfort Modes
- Evaporative, Bucket-free
Premium with Heat
Silini Desktop USB AC
- USB, Car USB, 110V Plugs
- Fan Reaches 8+ feet
- 3 Fan Speeds
- Tank Lasts up to 12 Hrs
- Top-rated Evap AC
Mini Evaporative Cooler
Frigidaire Evaporative Cooler
- Up to 450 square feet
- 13-gallon Tank
- Tank Lasts 24+ Hrs
- Cooling + Fan-only Mode
- 3 Fan Speeds w/ Oscillation
Large Evaporative Cooler
Best Portable Air Conditioners: Full Reviews
These reviews offer more detail and a fuller description of each of the best portable air conditioners and evaporative air coolers.
Quick distinction: A portable AC is a true air conditioner. It uses refrigerant to collect heat indoors and dump it outside, cooling the inside air by removing heat from it.
An evaporative air cooler does not remove heat from the space. Instead, it cools people in the room through evaporation – just as moisture evaporating off your skin makes it feel cooler. The technology is fully explained below in the Portable AC Buying Guide.
Our Rating System: Here is what we looked at in choosing our list of the Top 12 Portable Air Conditioners & Coolers. We rate each category from 1-5 Stars, though the units in this list are all 4 to 5 stars since they are top products.
- Quality: We looked for hardworking, durable models built with quality parts. The units chosen have a track record of reliability.
- Performance: Fast cooling, removal of a high volume of moisture, various modes in addition to AC such as Dehumidify Mode, Fan-only Mode and/or Heat Mode. When Dehumidify Mode, aka Dry Mode, is used, moisture is removed from the air. Heat is removed too, but instead of it being exhausted from the room, which would cool the room, it is returned to the room. Air temperature doesn’t drop. Dry Mode is ideal for cool days with high humidity that makes the air chilly, damp, clammy. You wouldn’t want colder air, but getting rid of the damp makes the room more comfortable.
- Features: Most of the portable air conditioners on the list are evaporative units. This means that the moisture removed from the air is evaporated out the exhaust hose. Again, this is regarding the ACs. The Evaporative Coolers use the term too, but in a different manner, which is explained below. In addition, most ACs on the list have 24-hour timers, remotes with all the unit functions, multiple-speed fans
- User Reviews: We look at ratings and reviews from many platforms including Amazon. It is useful to see what actual users of the products are saying about them. Fakespot is occasionally used to analyze whether the reviews seem legitimate or are faked. We do not consider reviews on the manufacturer sites.
Best Pro: This is the user review that best summarizes those with a positive experience.
Best Con: This is the user review that best summarizes those with a positive experience.
5. Overall Rating: The ratings from the categories above are averaged for an overall score.
6. Best Use: This is where the best fit for each AC/cooler is defined.
OK, on to the Full Reviews.
#1 Ivation 12,000 BTU Portable Air Conditioner – Powerful AC Unit & Dehumidifier
This is the best portable air conditioner available today. It is loaded with features, has 5 modes that allow you to customize indoor comfort and delivers outstanding performance and quality. On top of that, it is a really good value, given its competitive cost.
The noise level on this unit is about average. It runs at 55 decibels on high and estimated 52 dB on the lowest setting. There’s a normal amount of “buzz” when the compressor kicks on.
If quiet operation is your top priority in a good portable air conditioner, see the Quilo and JHS models below. They are the quietest portable ACs on this list. We’ve also completed a Review and Buying Guide of the Quietest Portable Air Conditioners.
- Quality: 4.5 – Very good build. The unit has a solid feel. Caster wheels, window kit and hose should last indefinitely.
- Performance: 5 – This unit’s modes are Air Conditioning, Humidification (drying the air without chilling it), Fan-only for moving air, Sleep Mode for saving energy while sleeping and Auto Mode – set the temperature you want, and the unit will automatically run in the right mode to hit that temperature based on the conditions in the room.
- Features: 5 – It is an evaporative portable air conditioner, so most of the condensation evaporates out the exhaust hose. If you’re using the unit as a dehumidifier, then you might want to attach a garden hose and run it to a 5-gallon pail or, if available, a floor drain. This Ivation portable air conditioner has the other ‘bells & whistles,’ a full-feature remote, 24-hour timer and one of the longest exhaust hoses available at about 5 feet. The long hose gives you a little more flexibility in placing the AC where it won’t be in the way or where it delivers the best cooling for the room.
- User Reviews: 4.5 Reviews are 80% to 83% positive across the platforms. Does that seem low? They are quite good for a portable AC.
One of the truths about portable air conditioners is that window air conditioners are generally rated higher. We cover that issue below when the two appliance types are compared.
- Best Pro: “This AC cools our south-facing bedroom pretty quick in the evening and doesn’t wake me up tho I’m a light sleeper.”
- Best Con: “Does not effectively cool my 425 square foot insulated garage. On a 95 degree day in Scottsdale AZ I’m lucky if it gets it to 85.” [Editors Note: This is a common concern for all portable air conditioners, that they are overrated for how much space they can cool. The section below on ASHRAE vs. DOE/SACC BTU ratings clarifies it. Plus, outside temperature and how well the room is insulated are major factors in how well any air conditioner can perform. Garages, even insulated garages, often don’t have the level of insulation a home does.]
- Overall Rating: 4.75 out of 5
- Best Use: Bedrooms, offices and other enclosed rooms (vs on open floor plan) up to about 350 square feet. It’s also a good budget portable air conditioner, even though it’s features and performance are excellent.
Did you know? Fakespot is a website that analyzes the truthfulness of ‘user reviews’ online. The site gives this portable AC page an ‘A’ rating for genuine reviews.
Best for Very Small Room
#2 Danby Portable Air Conditioner 6000 BTU White
You could call this a personal-size portable air conditioner. It’s ideal for a small bedroom or office. Some people put it in a bathroom that doesn’t get good airflow from central air conditioning.
This unit covers basic performance quite well.
- Quality – 4.5: Danby products get good ratings for quality and reliability. This unit should give you 5-10 years of trouble-free cooling.
- Performance – 4.5: Your climate control options with this Danby portable air conditioner are AC, Dry/Dehumidify and Fan-only. That’s pretty good for a cheap portable AC in terms of the price.
The Danby product page suggest the unit will cool up to 250 square feet. That’s not realistic. We recommend it for about half that in hot weather, maybe 150 square feet in warm weather.
- Features: 4.5 – Nice Control panel, full-function remote control and 2-speed fan. The 24-hour timer can help you use the AC efficiently. The features package is very good for a small room portable air conditioner.
- User Reviews: 4 – About 80% of users recommend this Danby portable air conditioner. Some of those giving it negative ratings apparently thought it had heat mode too. There is no heat mode, and Danby doesn’t claim there is.
- Best Pro: “Powerful fan speed for its size. I can feel the breeze across the room.”
- Best Con: “The noise level is about the same as a hotel AC.”
- Overall Rating: 4.375 out of 5
- Best Use: A very small room in a hot climate or an average bedroom or office where weather gets warm but not extremely hot.
Did you know? This Danby portable AC is available in other sizes – 10K, 12K and 14K BTUs. If you’ve had a good experience with a Danby appliance and need a larger size for another location, check out the other sizes. Information on them can be viewed via the link above. Select the link and choose the AC size you need for more information.
Best for Bedroom
#3 LG LP0818WNR 8,000 BTU Portable Air Conditioner
LG is a top-tier appliance maker that combines quality and innovation. This unit is a mid-size portable air conditioner that is quiet and delivers good performance.
- Quality: 5 – LG’s parts and workmanship are among the best on the market.
- Performance: 4.5 – This LG portable air conditioner has AC, Dry/Dehumidify and Fan-only modes. That’s standard for most portable ACs in this class. This unit also has auto-evaporation, so you can run it continuously on AC mode without having to empty a bucket.
- Features: 4.5 – Auto-evaporation, as mentioned, is a plus in any climate. Oscillating louvers move air side to side for balanced cooling. The LED panel and LCD full-function remote make it very easy to set, check and change the settings on this unit.
- User Reviews: 4.5 – This unit receives ratings from reviewers of 82% to 90%, higher than most other models.
- Best Pro: “Cranks out cold air and keeps my 184 square foot bedroom cool here in sunny, hot Salt Lake City.”
- Best Con: “It takes 90 minutes to reduce the temperature in our bedroom 7 or 8 degrees. I’ve learned to turn it on 2 hours before going to bed.”
- Overall Rating: 4.625 out of 5
- Best Use: An average-size bedroom, office or enclosed space. As the “con” reviewer recommended, sometimes it takes a while to lower the temperature, so you might want to use the timer to start the air conditioner a few hours before you plan to use the room.
Best for Medium Room
#4 JHS 10,000 BTU Portable Air Conditioner
One of the surprises we’ve found over the years of reviewing air conditioners and other HVAC equipment is that unfamiliar names sometimes make really good equipment.
Being unfamiliar is how all new brands start, and only the best make a “name” for themselves. JHS seems to have the right formula with this 10,000 BTU portable air conditioner. It boasts good quality, and users are the proof. It has high ratings among those consumers that are using it to meet their cooling needs.
- Quality: 4 – Most users have a good experience with this portable AC. It runs well, has a powerful fan and gives them the cooling and dehumidification they expect. A small percent say the unit arrived in non-working condition or soon failed. Amazon and the manufacturer have an easy return policy if you get a “lemon.”
- Performance: 4.5 – This unit cools in hot weather, has Dehumidify/Dry mode for damp weather when you want drier but not cooler air and Fan-only mode to move the air or create “white noise” for sleeping or focusing on work or studies.
- Features: 4.5 – Everything but heat. This JHS portable air conditioner has the features you’d expect: 24-hour programable Timer, full-function Remote, LED digital display and stainless steel caster wheels. The dehumidification rate of 6+ gallons of moisture per day is good, not great.
- User Reviews: 4 – About 77% of all verified users recommend buying this model. The truth is, that’s pretty good for a portable AC.
- Best Pro: “We bought this AC to cool our bedroom suite which has always been the hottest room in the house. The central AC doesn’t reach it very well. This unit easily lowers the temperature from 78 or 80 to a more comfortable 70 degrees for sleeping.”
- Best Con: “After 2.5 months the compressor broke, so no more AC. Just a fan. Thankfully the company/Amazon is replacing it for free.”
- Overall Rating: 4.25 out of 5
- Best Use: The biggest ‘con’ of portable air conditioners is that they don’t cool the amount of space the manufacturer says they do. So, we recommend this unit to cool up to 250 square feet in moderate heat, less in intense heat or in a room that faces south or west. It should serve a room 12x20, 16x15 or similar.
Best for Large Room
#5 Quilo 14000 BTU Portable Air Conditioner
This unit is one of the Quietest Portable AC Reviews and Buying Guide. The Sleep Mode noise level is 45 decibels, the lowest noise level available in a portable air conditioner.
Overall, it is a very quiet AC with a top operating noise level of just 52 decibels. Adapting an old saying, if you can find a quieter portable air conditioner, buy it.
- Quality: 4 – Reliability is well above average. You should get 7+ years of durability from this unit.
- Performance: 4.5 – This 14000 portable air conditioner has Air Conditioner mode, Dry/Dehumidification mode, Sleep Mode that lowers the fan speed while keeping the air cool and Auto-evaporation.
The Auto-evap means you don’t have to empty a bucket while the AC removes about 10 gallons of moisture per day. That’s a lot of humidity being removed from your living space.
- Features: 5 – This unit has everything but heat and WiFi: Full-function remote, 24-hour programmable Timer for energy efficiency and convenience, Evaporating exhaust and a Sleep Mode that is second to none.
- User Reviews: 4 – Between 70% and 80% of users would buy this unit again. That’s higher than average for portable air conditioners.
- Best Pro: “This AC keeps our bedroom very cool in Missouri summers and is the quietest of the 3 Portable ACs we’ve owned. Recommended.”
- Best Con: “My 600 square foot apartment is 2 degrees cooler after running this thing or 4 hours – 84 down to 82.” [Editor’s Note – That’s not surprising. Regardless of what the manufacturer says, a 14000 BTU portable air conditioner is right for about 350 square feet of space. Sizing a portable AC is discussed in detail in the Portable AC Buying Guide below. It is one of the most important factors when choosing the best portable air conditioner for your home.]
- Overall Rating: 4.375 out of 5
- Best Use: This unit will do the job best in large bedrooms, large offices, insulated 2-car garages and enclosed space to about 350 or 400 square feet.
Best Dual Hose
#6 Whynter ARC-143MX 14,000 BTU Dual Hose Portable Air Conditioner
A dual hose portable air conditioner is more efficient because it doesn’t suck in warm outside air as it exhausts air from indoors. The potential is up to 30% more cooling power and efficiency.
This unit and other top Whynter portable air conditioners made Consumer Reports Top portable AC list and was chosen #1 by Good Housekeeping.
See our Best Dual Hose Portable Air Conditioners Reviews and Guide for picks for the best dual hose models in various niches including different sizes.
- Quality: 4 – This is a well-built, quiet AC that should give you 5-10 years of dependable service.
- Performance: 5 – Besides AC Mode, this unit gives you Dry/Dehumidify mode for damp, cool days and Fan-only mode that is often used as white noise in addition to improving airflow and air filtering.
- Features: 4.5 – Whynter patented its drain-free Auto-drain function. It fully exhausts all the condensate except in extremely humid climates. You’ll rarely have to empty the drain tank. It has the basics you’d expect: 24-Hour programable timer, Full-function Remote and two filters – a carbon filter for odors and the main filter that is coated for antimicrobial performance.
- User Reviews: 4 Reviews are 70% to 80% positive, which is solid for a dual hose portable AC.
- Best Pro: “I returned the first unit I bought because it couldn’t noticeably cool our 325 square foot bedroom in 10 hours. I replaced it with this one, and the room’s temperature began dropping after an hour. Powerful AC and quiet too.”
- Best Con: “We bought this because of the CR Magazine report and put it in our 350 s.f. bonus room above the garage (which gets really hot in summer). It cooled the room down but had to work really hard to do it. The compressor never seemed to stop. Finally during the second summer it quit. Planning to replace it with a big window AC.”
- Overall Rating: 4.5 out of 5
- Best Use: Enclosed rooms up to about 350 square feet. It is a popular choice for bedrooms, offices and living rooms.
Best with WiFi & Alexa
#7 RolliCool Alexa-Enabled Portable Air Conditioner 12,000 BTU AC Unit with Heater
This unit, even without its connectivity, would be worth considering. Add WiFi and voice command using Alexa to the mix, and this quality unit is a winner. Especially at this price! It offers heat pump technology – air conditioning in warm weather and true heat pump heating in cold weather. When heating, the refrigerant flow is reversed. It gathers heat from outdoor air and releases it into the air inside.
- Quality: 4 – The RolliCool offers good quality for a portable air conditioner. Some units have arrived not working. But Amazon has a good return policy for such cases. Note: RolliCool makes similar but not identical units in 10,000 and 14,000 BTU units. However, we can’t recommend them. The quality isn’t acceptable.
- Performance: 5 – This is where the unit really shines. Modes are AC, Heat, Dehumidify, Fan-only and Auto mode. The last mode allows you to set the thermostat to the temperature you want, and the unit will automatically select the right mode to keep your indoor climate where you want it.
- Features: 4.5 – WiFi & App for mobile monitoring and control, voice command with Amazon Alexa, 24-hour timer, Remote.
- User Reviews: 4 – About three-quarters of users are satisfied with this unit. About a quarter experience mechanical differences or, more commonly, difficulty in getting it to pair with their smart devices or connect to WiFi.
- Best Pro: “Our bonus room above the garage gets quite warm even when the central AC is on. This unit helps keep the room comfortable in the afternoon/evening when it is warmest outside.”
- Best Con: “There are no heat ducts in our 350 square foot basement TV area. So, we bought this for heat in winter and might use it as an AC in summer. However, it doesn’t raise the temp in our cold basement by more than 3 or 4 degrees.”
- Overall Rating: 4.375 out of 5
- Best Use: Supplemental cooling and heating. No portable air conditioner is designed to be the only source of heat or AC, except where not much of either is needed. While the literature says this can serve up to 550 square feet, 14,000 BTU units are best for about 400 square feet.
Editor’s Choice - Top Premium
#8 SereneLife 12,000 BTU Portable Air Conditioner
The two SereneLife portable air conditioners on this list are the highest rated models available. They get high marks from users for quality and performance.
- Quality: 4.5 – This is a durable, hard-working portable AC. It should deliver 7-10 years of dependable air conditioning.
- Performance: 4.5 – The four modes are AC, Dry/Dehumidify without cooling, and Fan-only mode for moving the air. This is an evaporative AC, so most of the moisture is exhausted.
- Features: 4.5 – This, like most on the list, is an auto-evaporative unit. This means that it will rarely if ever have to be emptied. Most of the moisture that is removed from the air is vented out the hose attached to the window kit. It’s got the other features you’d expect – Timer, Remote, air filter and multispeed fan.
- User Reviews: 4.5 – 85% to 90% of those that have bought this unit recommend it and give it high marks.
- Best Pro: “The unit quickly cools a 250 square foot home office in warm weather. I use it to dry the air in damp, cool weather, and it does a great job too.”
- Best Con: “I shopped around. This is one of the most expensive models. The great review scores influenced my buying decision. Let’s hope it lives up to the hype.”
- Overall Rating: 4.5 out of 5
- Best Use: A 12,000 BTU unit will adequately serve up to 300 square feet unless the room is very warm, and then it’s right for up to 225 square feet.
Best Premium with HEAT
#9 SereneLife 12,000 BTU Portable Air Conditioner / Heat Pump
This model is exactly the same as the one above except that it has a reversal valve. This means that it can be turned to Heat Mode, and the refrigerant will collect heat from outside air and disperse it inside. That’s what a heat pump does, and this is a heat pump AC.
Quality, performance, features, etc., can be viewed in the review above. Again, the only difference is in performance – this unit also supplies heat. SereneLife makes a 10K BTU unit with heat. We recommend sticking with the 12,000 BTU model – with a portable air conditioner, larger is generally better because they simply do not cool as powerfully as a comparably sized window air conditioner.
Best Mini Evaporative Cooler
#10 Mini Air Conditioner Desktop USB Model by Silini
This is not an air conditioner, as explained in our Evaporative Air Cooler Reviews and Buying Guide.
Instead, it cools air through evaporation. This is an effective evaporative air cooler for personal use – right in front of you on a desktop, next to your bed, on a patio table nearby, etc.
- Quality: 4.5 – The fan, case and other parts are well built. It is easy to fill.
- Performance: 4.5 – As long as you understand that this unit will only cool you if it is within reach, or maybe up to 10 feet if the room isn’t terribly warm, then you’ll be satisfied with its performance. Expect up to 8 hours of cooling on a single tank of water.
- Features: 4.5 – You have 3 ways to power it – a USB into a laptop or other device with a USB port, a Car USB that plugs into a power source in a vehicle, boat, etc., and a standard 110V plug adapter. It has 3 fan speeds.
- User Reviews: 4.5 – This best-selling evaporative air cooler is recommended by almost 90% of consumers.
- Best Pro: “The fan is more powerful and the air is colder come out of it than I expected. And the price is excellent.”
- Best Con: “This is not an AC! It doesn’t do much unless its right next to you on a hot deck.”
- Overall Rating: 4.5 out of 5
- Best Use: The best “con” review says it well. This unit, especially outside, works best when it is near you. If you keep it close, you’ll likely be impressed with its cooling ability.
Best Large Area Evaporative Cooler
#11 Frigidaire Portable Evaporative Air Fan Swamp Cooler
Large evaporative air coolers can be effective in areas with low to moderate humidity levels. They lose effectiveness in high humidity where a simple fan is a better, more affordable choice than a swamp cooler. Or, of course, a window AC, mini split AC or central AC are good choices too. You can find information about all those cooling types with a search of PickHVAC.
- Quality: 4.5 – It is well-built and solid.
- Performance: 4.5 – There are two modes, Cooling and Fan-only. The 3-speed fan oscillates in either mode to give broader cooling to a large room. Expect decent cooling in rooms up to about 20x20, or 400 square feet. With the large 13-gallon tank, it can run for 24 hours or more without a refill. Or connect a hose to it for constant operation. Ice packs are included. However, ice isn’t necessary. In fact, it only marginally raises the temperature of the air coming out of the unit. Evaporation is the real key to colder air.
- Features: 4.5 – It has a 3-speed fan, 13-gallon tank and a Remote and Timer that add a lot of convenience.
- User Reviews: 4 – Most users like it, though the fact that it is quite large is mentioned by many users. The size is 32.5 x 21 x 18.2 inches.
- Best Pro: “This thing cools my 1.5-car garage from 85 degrees down to the low 70s and keeps it there all afternoon. Very effective.”
- Best Con: “I bought the 600 CFM model, and it is junk. I should have bought this 500 CFM model recommended by my brother.” Editor’s Note: The user makes a good point. Frigidaire makes a larger unit. The design is different, and it is a fail.
- Overall Rating: 4.375 out of 5
- Best Use: In space up to about 400 square feet. It is most effective in fairly dry air – 40% humidity or less. It can be used indoors or outside, but is less effective outside in windy conditions.
Portable Air Conditioner Buying Guide
In this Buying Guide, we’ll cover several important topics that should assist you in your buying decision.
Portable vs Window Air Conditioners with Pros & Cons
In general, homeowners give higher ratings to window air conditioners than to portable air conditioners.
Perhaps these portable air conditioner pros and cons will shed light on why this is true.
Portable AC Pros Compared to Window Air Conditioners
Portable AC Cons Compared to Window Air Conditioners
Portable ACs vs Whole-house ACs
If you have central AC, is there a place in your home for a portable air conditioner?
Potentially yes. Here’s what a portable AC can do for you. The same advantages apply to a window AC.
Portable AC vs Evaporative Air Cooler
Evaporative air coolers are sometimes called mini air conditioners or personal air conditioners. They are not air conditioners. Here’s an overview of how they work.
1. Water is poured into a tank (and some also have garden hose connections for constant operation).
2. The water is wicked up or absorbed by absorbent material.
3. A fan pulls air through the material which has the effect of causing heat in the air to evaporate water out of the absorbent material. As you likely know, evaporation removes heat, and that makes the air cooler. Think about water evaporating off your skin – it makes your skin cooler. The cooler air is blown out of the unit. A good evaporative air cooler can lower the temperature of the air by 8 to 20 degrees.
Portable AC Advantages
- They remove moisture from the air. An evaporative air cooler adds moisture.
- They remove heat from the room. An evaporative air cooler blows cooler air in one or two directions, but the heat removed remains in the room, just not in the air you feel blowing your way. In other words, in an enclosed room, the temperature cannot be lowered using an evaporative cooler.
- They work in any region of the country, including very humid areas. Evaporative air coolers are effective where humidity is relatively low. Where humidity is high, the water won’t evaporate as well, if at all, at evaporation is necessary for removing heat from the air.
Evaporative Cooler Advantages
- They generally cost less than a portable AC.
- They are lighter and easier to move from place to place.
BTU Ratings: ASHRAE vs US DOE Ratings
This is the so-called elephant in the room that some portable AC manufacturers don’t like to discuss.
These units simply are not as efficient as other AC types. Here is why – and why there are two separate BTU rating systems.
The problem: When air is exhausted out the window hose, it creates negative air pressure indoors.
The result: As air goes out, air is sucked indoors through any drafty location. No home is airtight. The air drawn in is warm, humid air.
The bottom line: The effectiveness of a portable AC is significantly diminished by the air infiltration.
Two Rating Systems
The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) tests the basic effectiveness of air conditioners of all types, as it has done for decades. One test – How many BTUs of heat can a unit remove from the air per hour. The test does not factor infiltration – how much heat is sucked back into your home.
This infiltration is not a factor with a window AC or central air conditioning.
At some point, this built-in inefficiency came to the attention of the US Department of Energy. For the sake of giving an accurate rating to consumers, the DOE developed the Seasonally Adjusted Cooling Capacity (SACC) that does account for infiltration.
While there isn’t a formula that covers all portable air conditioners, the DOE SACC rating is usually 50% to 60% of the ASHRAE rating for how many BTUs the unit can remove per hour. Examples included for models we’ve reviewed are:
14,000 ASHRAE = 7,500 SACC
12,000 ASHRAE = 6,500 SACC
10,000 ASHRAE = 6,000 SACC
8,000 ASHRAE = 4,500 SACC
6,000 ASHRAE = 3,000 SACC
Not all product pages list the SACC rating. Many list them both. Only a few list just the SACC rating. If there is only one BTU rating given, it is probably the ASHRAE rating and you should consider that the SACC rating is about half.
You can also go by the chart in the next section.
Sizing your Portable Air Conditioner
It is important to buy a unit rated to serve the amount of space you have – or more. With central air conditioners, you should not choose one that is too big for your home. But because of efficiency issues with portable air conditioners, going a size up isn’t an issue.
This chart is a starting point. See the addition points below it for properly sizing a portable AC.
We recommend that you choose a unit that is 1,000 BTUs larger than the chart recommends for each of these issues:
1. Ceilings higher than 8 feet.
2. The room faces south or west and isn’t shaded by trees.
3. Is a room often occupied by 3 or more people.
4. Is for a kitchen, since cooking makes the room hotter and more humid.
How to Make a Portable AC More Efficient & Effective
These home efficiency tips will help you air condition and heat your home more efficiently.
1. Make sure your home’s attic has the appropriate amount of insulation.
2. Use weather stripping around drafty doors and windows.
3. When you upgrade windows and doors, choose those with better insulation values.
Specifically for portable air conditioners:
1. Choose one with a programable timer, so you can determine when the unit comes on and shuts off. That way, you don’t have to leave it on while you’re away to have the space comfortable when you get home. Program the AC to come on an hour before you arrive.
2. Consider a unit with WiFi. It is the surest way to reduce unused air conditioning. When you’re on your way home, use the app to turn on the air conditioner or to turn down the unit’s thermostat to a more comfortable level.
3. Use the foam that is included with your window kit to create as airtight a connection as possible.
This Buying Guide is just one of many we’ve created for portable air conditioners. These might be of use too.
Portable AC Brand Reviews:
Portable AC Buying Guides with Top Picks in each: