8 Best Ventless Air Conditioners For Cool Summer Days

Josh Mitchell

Written By

Josh Mitchell

Expert Reviewed By

Holly Curell

Last Updated On

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Ventless air conditioners are a common request as venting options can be challenging for many homeowners. Unfortunately, portable ACs almost always need some kind of venting to remove the hot air that is generated from the inside of the unit. 

With recent improvements in technology, some brands are pushing the boundaries of the traditional room AC, with Coolzy and Dreo being notable companies. Beyond those, swamp coolers or air coolers offer ventless cooling solutions for indoor and outdoor use. 

I can tell you, though, not all ACs and evaporative coolers are created equal. Below, I’ll share the ones that I have had success using.

Quick Glance - My Recommendations

Coolzy Pro

  • 2 x venting solutions
  • AC + direct spot cooling
  • Very energy efficient

Portable Swamp Coolers - 1300 CFM MC18M...

HESSAIRE MC18M

  • Low cost to run
  • Easy to setup and use
  • For indoor and outdoor use

Portable Swamp Coolers - 3100 CFM MC37M...

Hessaire MC37M

  • Good for low-humid places
  • Big 10.3 gallon tank
  • Excellent for outdoor use

*PSA* - Most 'Ventless Air Conditioners' Are Not TRUE ACs

I want to be clear upfront and note that while my article highlights ventless ACs, this is actually just a misnomer for evaporative coolers (sometimes called swamp coolers). 

Do these products offer cooling? Yes. Are they really air conditioners? Not in my book, for a few reasons. I’ll go into much more detail on this further on.

There is one exception here, and that’s my top choice product – the Coolzy – which you’ll see if the only true ventless AC on the market. Read on!

How Do Evaporative Coolers Work?

Swamp coolers work by evaporating water. A powerful fan pulls hot air into a chamber containing water-soaked pads, and then the water evaporates and passes out cooler air.

8 Most Effective Ventless Air Conditioners on the Market

1. Coolzy Pro

4.7

Overall Score


Ease of Use

4.5

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Cooling Ability

5.0

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Value for Money

4.75

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Who is the Coolzy Pro best for?

I recommend the Coolzy to anyone looking for a more traditional air conditioner but who is happy to have a model for personal use rather than whole-room use. 

Pros
  • Different venting options
  • Compressor-driven design
  • Plug and go
  • Does not require water
CONS
  • Expensive upfront cost

The Coolzy Pro is not only my top choice for a ventless air conditioner, but it’s also the only product on my list that I’d be willing to call a “true” air conditioner. 

Just like a traditional portable AC, the Coolzy is compressor-driven and can be vented out of a window or door. 

Unlike traditional portable ACs though, the Coolzy doesn’t have to be vented. 

It won’t cool an entire room like a traditional AC, but it will cool 1-2 people sitting in front of it, with warmer air blowing out the back and directed by a unique design. 

My favorite thing about the Coolzy is its plug-and-go operation, which has made it the ideal camping solution for me (as long as I’m at a site with an electricity hook-up).

Unlike the Hessaire models, I don’t have to keep refilling it with water to get the desired effect.

Coolzy Pro

The Coolzy also won’t increase the humidity around me, which after a long day of hiking, is honestly the last thing I want. 

A product like this seems almost too good to be true, but it’s just the first (and only) of it’s kind, so be wary of knock-offs. The Coolzy was designed by Australians looking for a solution to beat the heat in the harsh outback.

Given all its functionality, I was impressed that the Coolzy weighs only 35 lbs, which made it easy for me to move around on my camping trip. 

Some ventless ACs can be really heavy, like the Portacool model, which is already 99 lbs before adding water!

Overall, I love that the Coolzy has served me in many different scenarios from camping to supplementing my home AC to cooling me down on the porch on a hot summer night.

Feature

Details

CFM Airflow

-

Power Consumption

340 W

Room Size (Cooling Area)

88 cu ft (personal cooling)

Dimensions

18 x 21 x 10 in

Water Tank Capacity

n/a

Warranty

2 years


2. HESSAIRE MC18M

4.5

Overall Score


Ease of Use

5.0

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Cooling Ability

3.5

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Value for Money

5.0

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Who is the Hessaire MC18M best for?

I recommend this Hessaire MC18M model to first-time swamp cooler users looking for something easy to use and maintain at an affordable price.

Pros
  • An effective and cost-efficient approach to cooling
  • Incredibly easy to set up and get up and running
  • Long-lasting and reliable budget option
  • Will work both indoors and outdoors
  • Can be paired with a hose for continuous workload
CONS
  • It can be a bit loud when in cooling mode on high
  • Limited additional features like remote control, timer, low-water alarm, etc.
  • Shrap hose connector
  • 1-year warranty

For those choosing the evaporative cooler route, I highly recommend the Hessaire MC18M. 

On top of being one of the most affordable items on my list (about half the price of the Hessaire MC37M), it’s also the most reliable. 

I've had the MC18M in my workshop since 2020, and it has outlived most of the evaporative coolers I've had over the years.

Personally, I've mostly used it on high cooling mode because I've hooked it up to a hose, and I exclusively use it in a workshop, which tends to get pretty darn hot.

On the other hand, I'd say that if you plan on using it in your bedroom or a living room - fan-only on high or cooling on low should do the trick.

The water tank on the Hessaire MC18M is 4.8 gallons, which I thought was on the lower side compared to Vagkri’s 8-gallon reservoir. 

That said, I highly suggest placing this model where you want it and then filling it with water because it’s very heavy when filled up completely. (Don’t ask me how I know!)

Performance-wise - there’s more than meets the eye here. The fan can go up to 1300 CFM, so unlike the Coolzy, I can actually feel the cool air even when I’m standing 10-15 feet away.

Also, the MC18M can comfortably cool down 300-350 sq ft for up to four hours, but the space is right; you could probably feel the difference up to 500 sq ft.

As with any indoor use with a ventless air conditioner, I highly recommend keeping a window open and running a dehumidifier simultaneously to prevent moisture build-up on the walls. 

In fact, the instructions for this model even state that when you’re done using the unit on cooling mode, you must set it on fan-only mode and run it for at least 30 minutes to dry the internal filter and prevent bacteria and mold from growing.

HESSAIRE MC18M parts

Feature

Details

CFM Airflow

1300

Power Consumption

85W

Room Size (Cooling Area)

Up to 350 sq ft

Dimensions

28 x 22 x 12 in

Water Tank Capacity

4.8 gal

Warranty

1 year


3. Hessaire MC37M

4.4

Overall Score


Ease of Use

4.5

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Cooling Ability

4.0

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Value for Money

4.75

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Who is the MC37M best for?

I recommend the Hessaire MC37M to people looking for a powerful mid-sized option for cooling spaces of up to 950 square feet. 

Pros
  • Excellent choice for low-humidity climates
  • Easy to use with garden hose
  • Large 10.3 gallon tank
  • Especially effective for outdoor cooling solution
CONS
  • Manual filling is time-consuming
  • Can increase indoor humidity too much

Hessaire is a company that I know and trust when it comes to evaporative cooling, so you’ll actually see them pop up three times on my list here. 

The Hessaire MC37M is the big brother to the MC18M above and is suitable for spaces of up to 950 square feet, which is really impressive. 

Hessaire MC37M

I recently recommended this model to a customer in Northern Michigan who was looking to cool the second story of their home during the peak summer months of July and August. 

The setup I came up with included positioning the Hessaire MC37M at one end of the upstairs floorspace and having a window fan blowing outside on the opposite end.

This really helped promote air circulation and also helped prevent humidity from building up in the space.

While this worked fantastically in Northern Michigan, the Hessaire MC37M is not made for very humid environments. The same setup in South Carolina, for example, would probably yield poor results. 

The tank size on the MC37M is 10.3 gallons, and when set on a low setting can run continuously for about 4 hours. 

It does have the option to attach a hose on the back for continuous use, which I have found is a great setup for outdoor use, such as on a pool deck.

The MC37M is about twice the price of its smaller sibling, the MC18M, but I’d also argue that it’s about twice as powerful and more aesthetically pleasing as well. 

At this price point, I only wish it came with more advanced features, such as a timer and remote control, like the Vagkri model I reviewed below. 

Feature

Details

CFM Airflow

3100

Power Consumption

250 W

Room Size (Cooling Area)

950 sq ft

Dimensions

24 x 16 x 38 in

Water Tank Capacity

10.3 gal

Warranty

1 years


4. Dreo IceWind

4.3

Overall Score


Ease of Use

4.5

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Cooling Ability

4.0

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Value for Money

4.25

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Who is the Dreo IceWind best for?

I recommend this Dreo IceWind model to people who want to try out the unique cooling design that uses ice packs to cool.

Pros
  • Easy-to-clean filters
  • No water filling required
  • Oscillating fan is nice for room coverage
  • Super quiet on sleep mode: 35 dB
  • Low energy use of 50 watts
CONS
  • Requires refreezing of ice packs
  • Pricy for a fan

The Dreo IceWind isn’t an evaporative cooler like the Hessaire or Honeywell models, but I’m including it on my list of ventless air conditioners because it’s an item I recommend to customers looking for overnight cooling in their bedrooms. 

The Icewind is essentially a tower fan like most of us have somewhere in our homes but with an upgraded twist.

By inserting two ice packs into the console, an even cooler breeze is created. 

The company doesn’t specify a particular coverage area but does note that the breeze can be felt from 21 feet away. I love putting product claims to the test, and can tell you that this is true! 

It’s made a huge difference in my sleeping temperature in my 300-square-foot bedroom. I have it supplementing my central AC so that I can just keep my bedroom cool without turning the thermostat down overnight.
Dreo IceWind

The price of the Dreo IceWind is a bit more than I would typically spend on a tower fan, but it’s functionality is well worth the price.

And given that it’s often out of stock online, others seem to agree with me. 

For those who are not ready to spend $400+ on the Coolzy, I would say the Dreo IceWind is an excellent place to start. It’s also the only product on my list that comes with color options – black and white. 

I love that this Dreo model comes with a remote and a timer that let me have full function of its features without having to get out of bed.

Of course, the only downside is that I have to remember to take out the ice packs and refreeze them each morning.

On the occasion that I forget, the tower fan still works well, but those ice packs sure do pack an extra punch. 

Feature

Details

CFM Airflow

-

Power Consumption

50W

Room Size (Cooling Area)

-

Dimensions

11.42 x 11.42 x 39.69 in

Water Tank Capacity

n/a

Warranty

1 years


5. VAGKRI 2100CFM Air Cooler

4.2

Overall Score


Ease of Use

4.5

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Cooling Ability

3.75

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Value for Money

4.25

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Who is the Vagkri best for?

I recommend this VAGKRI 2100CFM option to customers looking for a mid-sized option with a fairly long run time.

Pros
  • Exceptional energy efficiency
  • 120° oscillating fan for greater and more pleasant coverage
  • Runtime of 12 plus hours in the right conditions
  • Easily controlled and operated with a remote and a 24-hour timer
  • Excellent cooling performance in both closed and open spaces
CONS
  • Faulty water pump on occasion
  • Noise (over 60 dB) can be overwhelming in closed spaces
  • Can easily raise the humidity in smaller spaces

If my Hessaire MC18M ever stops working, I'm switching over to VAGKRI 2100CFM evaporative cooler in an instant for my workshop.

It’s what my brother uses, and I’ve become really impressed with the value of this ventless AC. 

Firstly, this one's the king of the energy-efficiency ratio. It draws 105 watts per hour, meaning running it day and night for a whole year will only cost $150-200.

This puppy has a 2100 CFM fan and a pretty large 8-gallon water tank, with a small open tank on top for ice trays (included with the AC unit) to further enhance its cooling performance.

VAGKRI 2100CFM Air Cooler

From what I’ve seen,  the Vagkri can comfortably chill a room up to 600 sq ft, and if the conditions are right, the manufacturers’ 700 sq ft claim isn’t too far-fetched. 

This option would be perfect if you’re looking for an option that’s somewhere between the Hessaire MC18M and Hessaire MC37M

This ventless air conditioner also comes with three separate fan speeds and an oscillating fan, meaning you can set the desired speed and cooling and allow yourself to be gently grazed by the cool air instead of being blasted by it at all times.

I found this particularly useful when we sat in front of it, and I never once got that familiar uncomfortable feeling you get when you sit or lie down in front of a fan or a cooler, and I just love that.

I also love it when ventless units come with remote controllers, timers, and other bells and whistles, and this one does. With only a few button pushes, I can turn this one on straight from the lawn chair and have it shut off automatically later.

The only thing I dislike about the Vagkri is that it does look quite industrial. My brother uses it in his workshop just fine, but I can’t imagine his wife letting him bring it into the living room unless the AC is totally broken.

Feature

Details

CFM Airflow

2100

Power Consumption

105 W

Room Size (Cooling Area)

Up to 600 sq ft

Dimensions

‎14.5 x 20.1 x 33.3 in

Water Tank Capacity

8 gal

Warranty

2 years


6. HESSAIRE MC61V

4.1

Overall Score


Ease of Use

4.0

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Cooling Ability

4.25

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Value for Money

4.0

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Who is the Hessaire MC16V best for?

The Hessair MC16V is for outdoor applications. These are excellent for those who want to cool down while they relax in the backyard.

Pros
  • Given the right conditions, it can drop the temperature as well as a traditional air conditioner
  • Highly efficient, both in terms of saving money and cooling the space
  • Oscillating fan cools down the space evenly
  • Comes with a hose connector for continuous use
CONS
  • Limited self-containing runtime
  • Can raise humidity levels in an instant
  • Noise levels can get overwhelming

I want to start by saying that if you're looking for a ventless air conditioner for inside your home, this isn't the one.

The other Hessaire models I’ve listed above will suit those scenarios, but the Hessaire MC61V is too powerful for in-home use.

Instead, I recommend the Hessaire MC61V for large open spaces. I recently found this to be the ideal solution for a neighbor looking to cool his pole barn while out there working on cars.

This is truly one of the best ventless air conditioners I have had the pleasure of using.

In terms of keeping the temperature down in a spacious workshop or a garage, this one can go toe-to-toe with some traditional units while leaving a smaller carbon footprint since it's only drawing 430 W at max.

HESSAIRE MC61V

Its 5300 CFM fan is more than powerful enough to cool down up to 1500 sq ft without feeling too overpowering if you maintain the distance. The pole barn we used it in is 1200 square feet. 

Upon setup, the temperature in the pole barn was a brutal 97 degrees on a hot August day, but this puppy managed to drop the temperature by 29 degrees, making it a breezy 70 F for my neighbor.

In other words, whether you’re chilling (pun intended) on the patio, working on your bike in a garage, or just barbecuing with your friends in your backyard - this ventless AC unit will make the summer afternoon feel like a pleasant summer night.

Despite its 14-gallon tank, this beast of an evaporative cooler has never gone beyond five hours for me, regardless of the fan speeds (which there are three, by the way). 

On the bright side, this one, just like the Hessaire MC18M, comes with a brass hose connector so that you can enjoy continuous use for those long days at the workshop.

Just remember, this one is not suitable for indoor use. 

Feature

Details

CFM Airflow

5300

Power Consumption

430 W

Room Size (Cooling Area)

Up to 1500 sq ft

Dimensions

‎17 x 28 x 46 in

Water Tank Capacity

14 gal

Warranty

2 years


7. Honeywell CS10XE

4.1

Overall Score


Ease of Use

5.0

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Cooling Ability

3.25

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Value for Money

4.0

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Who is Honeywell CS10XE best for?

This Honeywell CS10XE model is a good looking, remote controlled, indoor swamp cooler.

Pros
  • One of the most popular models for small space and immediate cooling
  • A great option for those unable to invest in heavy units
  • Very quiet, ideal for residential use
  • Small tank, yet respectable runtime
  • Compact size and nice appearance make it a good option for cozy apartments
CONS
  • It’s more expensive than more powerful evaporative coolers
  • Not efficient in a large room or outside spaces like a terrace
  • 1-year warranty at this price tag isn’t confidence-instilling

Some of my customers feel better off using products with brand names they already trust, and I understand that.

For my customers looking for ventless air conditioning in small outdoor spaces (up to 150 square feet), I recommend the Honeywell CS10XE. 

This is a 300 CFM ventless air conditioner has a 2.6 gallon capacity, so it’s much smaller than even the smallest Hessaire model ( MC18M), but it has an excellent 4 to 5-hour runtime. 

Honeywell CS10XE gallons
I actually use this model in my kitchen during the summer months, when it’s hot but I still want to cook up a nice hot meal!

Unlike most of the options on my list, such as the Coolzy or Hessaire models, the CS10XE is not rated for outdoor use.

However, in small and medium rooms, up to 150 sq ft, you will experience a refreshing gust that should make the heat more bearable.

I recently discovered that I can achieve even greater cooling success by filling the water tank first with ice and then water. 

Since this is a fairly gentle ventless unit, it doesn’t make much noise, so napping alongside it should be a breeze (intended pun). I registered it at 57 dB at high speed, which is typical for a personal cooling fan.

Also, this Honeywell option comes with all the features I could want in an indoor unit, such as a timer, carbon filters, a remote controller, and four fan speed settings.

As long as you keep water in the tank and the intake vents clean of debris and dust build-up, you will most likely never have an issue with this ventless air conditioning unit until it just wears out years down the road.

The only bone I have to pick with it is the price. It’s even more expensive than the Dreo fan, which is more powerful overall. 

That said, if you’re a Honeywell fan, this one will work nicely for small spaces. If your space is over 150 square feet, I recommend sizing up to the Honeywell CS10PE, which covers up to 280 square feet. 

They also have a larger indoor/outdoor model (Honeywell CO30XE) that can cover up to 320 square feet, but I honestly don’t have much experience with it yet. 

Feature

Details

CFM Airflow

300

Power Consumption

102 W

Room Size (Cooling Area)

Up to 150 sq ft

Dimensions

15.7 x 15.7 x 31 in

Water Tank Capacity

2.6 gal

Warranty

1 year


8. Portacool Jetstream 230

4.0

Overall Score


Ease of Use

4.0

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Cooling Ability

5.0

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Value for Money

3.0

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Who is Portacool Jetstream 230 best for?

Portacol Jetstream 230 is best for those looking for an efficient solution to cooling their commercial spaces such as garages, gyms, or shops.

Pros
  • Can lower temperature by 30F
  • Best warranty in the industry
  • Effective cooling for large warehouses
  • Stand-out customer service
  • Comes fully assembled and ready to go
CONS
  • Large upfront investment
  • Takes up floor space

Occasionally I’ll be ask to outfit a large storage warehouse with cooling. 

Warehouses are tricky, because they often have large truck doors open all the time, and their limited insulation can really make them a toaster in the summer. 

For these situations, I always recommend the Portacool brand. They have a lot of commercial-grade options for ventless cooling, but the product I find myself using time and again is the Jetstream 230. 

The Jetstream 230 is a monster of an evaporative cooler. At 7.5 feet tall, it is powerful enough to cool over 5,600 square feet at a velocity of 26 miles per hour!

It has a 65-gallon water tank but can keep your employees cooler all day long when hooked up to a continuous water supply. 

For places with a smaller footprint, Portacool has similar options, starting at 500 square foot coverage.

Portacool Jetstream 230

Obviously, the high price is often the turn-off for most of my clients. Still, when you’re talking about cooling such a massive open space, I think the $4700 price tag is pretty reasonable. 

What sets my mind at ease a bit is that Portacool offers a lifetime warranty on the Jetstream 270’s housing, and a full three year warranty on all the electrical components.

All the components are assembled in the USA. To further protect your investment, I would highly recommend purchasing one of their universal covers for protecting components in the off-season. 

The coolest setup I have used the Portacool Jetstream for is a July soccer tournament in North Carolina. We had one of these set up on each of the 8 fields, keeping players cool during play.

The only downside of the Jetstream (as well as any industrial appliance) is the noise. On high speed, this guy produces 80 dB of sound, so you’re definitely going to want to keep it far from anyone who has a stationary workspace (or give them some earplugs). 

Feature

Details

CFM Airflow

22,500

Power Consumption

375 W

Room Size (Cooling Area)

5625 sq ft

Dimensions

90 x 78 x 36 in

Water Tank Capacity

65 gal

Warranty

3 years

Comparing Ventless Portable AC Units

Preview

Name

Rating

CFM Airflow

Max Cooling Area

Price

Coolzy Pro

4.7

-

88 sq ft

Portable Swamp Coolers - 1300 CFM MC18M...

HESSAIRE

MC18M

4.5

1300

350 sq ft

Portable Swamp Coolers - 3100 CFM MC37M...

Hessaire

MC37M

4.4

3100

950 sq ft

Dreo Tower Fans That Blow Cold Air, 40'...

Dreo

IceWind

4.3

-

-

Evaporative Cooler, VAGKRI 2100CFM Air...

VAGKRI

4.2

2100

 600 sq ft

Hessaire MC61V Portable Evaporative Cooler,...

HESSAIRE

MC61V

4.1

5300

1500 sq ft

Honeywell 300 CFM Indoor Portable Evaporative...

Honeywell

CS10XE

4.1

300

150 sq ft

Portacool PACJS2701A1 Jetstream 270 Portable...

Portacool

Jetstream 230

4.0

22,500

5625 sq ft


evaporative coolers are not portable ACs

Trouble With Venting Your Home AC?

Consider Mini Split or Portable AC with a Window Kit

Now, often when people come to me looking for ventless air conditioners, it’s because they do not have the proper means to vent a traditional AC from the room.

If your space is truly enclosed (no windows or ventilation), you need to avoid the evaporative coolers that I’ve listed above. These will create too much extra humidity, which can lead to mold and water damage.

Temporarily, this may be fine when paired with a powerful dehumidifier, but evaporative coolers are never a long-term solution for enclosed spaces.

For windowless rooms, I often recommend mini splits as a permanent cooling option.

Yes, this will require professional installation and drilling through the wall, but the bonus is that these units often heat as well, offering year-round comfort.

For folks with windows, traditional portable ACs are my top recommendation, as they are way easier to install than a window unit, and require less management than evaporative coolers. 

Portable air conditioners often come with a window kit (as shown below), and the problem comes with the kit not being compatible with the window. 

portable AC venting

Thankfully, I’ve found that is the rigid portable window AC kit plates don’t work with a window, there are flexible seal kits out there that can make almost any window setup work. 

I have even installed full length kits that allowed my customer to vent their portable AC out of a sliding glass door.

In some scenarios, I have had to build a custom window venting solution using plywood. 


What To Look For In a Quality Ventless AC

I would never want anyone to just go and buy a ventless air conditioner just because it’s there or on sale, so let me tell you how a ventless air conditioner works and what you should look for in one.

Understanding Cooling Capacity Vs Coverage Area

The first thing you’ll see when shopping for a traditional portable air conditioner is BTU, which stands for British Thermal Units and is the measurement used to determine the cooling capacity of (portable) air conditioners.[2]

However, you won't see BTU when shopping for a ventless air conditioner.
match evaporative cooler to coverage area

The cooling capacity of ventless portable air conditioners is simply shown by its coverage area, which can be a vast difference.

Even my exception to the rule, the Coolzy Pro, doesn’t list BTUs but rather watts, mostly because it’s built for personal cooling only. 

What this means for you is that the only thing you have to know is the size of the area you want to cool down.[3

If you know that, you can easily pick out the winner from a list of different ventless AC units. I have included options on my list ranging from personal cooling (the Coolzy) to huge commercial spaces (the Portacool). 

I like to tell folks to to take room coverage with a grain of salt.

If the box reads “600 sq ft”, think of it as “400-500 sq ft”, as the maximum coverage area rating is usually only achievable in perfect conditions.


Factors That Affect The Performance Of Evaporative Coolers

Climate Conditions

Evaporative air coolers are made to be used in hot, low-humidity environments.

People in the Southwest (ie Nevada, Arizona, New Mexico) will all likely benefit from having a evaporative cooler.

The dry heat from the air causes the introduced water to evaporate, which in turn absorbs heat, effectively cooling the air the AC spews back out.

On the other hand, if the relative humidity is already high, there’s essentially no room for cooling to occur because the air is already saturated with moisture.

TL;DR: When asked about evaporative coolers, I always ask clients first where they live. These ventless air conditioners are not suitable for humid climates.

CLIMATE CONDITION

Air Flow Capacity or CFM

Airflow is the measure of the amount of air the fan can move in a given time. Airflow itself is measured in cubic feet per minute (CFM).

While a higher CFM is generally a good idea, I often see people making mistakes by going overboard with it.

So, make sure you’re looking at both CFM and cooling space. For example, the Portacool Jetstream 270 has a CFM of 22,500, which can be compared to a breeze of 26 miles per hour!

Tank Size and Runtime

Not all the products on my list have a water tank – the Coolzy and Dreo IceWind are exceptions to this section. 

The evaporative coolers on my list, such as the Hessaire products, have a runtime of several hours, (in)directly influenced by the size of the water tank.

What I mean by “(in)directly” is that “the bigger the tank, the greater the runtime” isn’t exactly true for swamp coolers, as those with larger tanks are usually designed for larger spaces, which means they require more water to be efficient at lowering the temperature.

Runtime, on the other hand, is usually anywhere between 3 to 6 hours for an average ventless air conditioner.

From my experience, anything above five hours is pretty good, and six-plus is a top-notch performance.

This can be upgraded by setting up continuous use with a garden hose, which most products on my list can accommodate, including the Vagkri and Portacool products.

Runtime

Noise Levels Can Get High - So Pay Attention!

Understanding the noise level is a prerequisite for any air conditioner.

Unfortunately, you'll have to make some sacrifices in this department if you choose a powerful unit because ventless air conditioners work rather loudly when you rev them up to the max. The Portacool Jetstream 270 runs at 80 dB at high speed. 

Generally, most ventless portable air conditioners run at 50-70 dB. For reference, an average conversion takes place at around 60 dB.[8] 

The Coolzy and Dreo IceWind are quieter than the evaporative coolers, at 45 dB and 35 dB, respectively.


Indoor Vs Outdoor Evaporative Coolers

Some evaporative coolers have dual use and can be used both indoors and outdoors, but it’s crucial to know if this is true for the product of your choice, or you’ll run into problems. 

Indoor ventless air conditioners (such as the Honeywell CS10XE) tend to be more aesthetically pleasing than their outdoor counterparts. They may also have more features, such as a timer, remote control, or air purification capabilities. 

They won’t have the power to perform in larger spaces (ie, the outdoors), though, and doing so will really tax their fans.

On the other hand, some evaporative coolers, like the Hessaire MC18M, are strictly for outdoor use. 

These units are much too powerful for indoor use, and the added moisture build-up can contribute to water damage, mold growth, and even breathing problems. 


Controllability, Fan Speed Options And Ease Of Use

When it comes to controlling ventless air conditioners, you won’t find the bells and whistles that come with traditional or window AC units – no temperature control, no app control, no automatic adjustability. 

That’s because these ventless options are meant for consistent use (preferably supervised). 

Instead, you can expect a ventless AC to be either manual (knob turning) or have a remote control. 

These units generally have 2-3 fan settings, and some, like the Hessaire MC37C, have a fan-only mode that bypasses the water function. 

This helps dry the evaporative filters and provides a standard fan breeze.  

I find most evaporative coolers easy to set up and use, given their basic controls.

That said, manually filling their water tanks and managing their runtime can be quite the task. I recommended setting up continuous hose use, if possible.


Size And Portability

Ventless air conditioners are all made to be fairly portable, and all of the products on my list, except for the Dreo IceWind have wheels for easy mobility. 

That said, I definitely recommend moving the evaporative cooler to your desired location before adding in the water, as each gallon adds over 8 lbs of weight. 

Commercial coolers like the Portacool Jetstream 270 weigh in at 200 lbs before water is added, so these solutions aren’t the most portable and should be moved sparingly. 

On the other hand, most of the mid-sized options can be easily moved around. The Hessaire MC18M, for example, is only 16 lbs without water and has a nice carrying handle for easy transport. 

I have actually used this model successfully for tailgating when hooked up to my small generator.


Ease Of Maintenance And Use

Maintenance on evaporative coolers and a little more involved than traditional portable ACs, but it is fairly straightforward and consists of three primary things:

  1. 1
    Manage the water tank as needed.
    This includes keeping it full when in use and emptying it completely when not in use. Failure to do so could lead to mold growth inside.
  2. 2
    Take advantage of the “fan-only” mode.
    Most units instruct you to run the machine on fan-only mode for 30 minutes after each use. This helps dry the filters and boosts their longevity.
  3. 3
    Clean & replace the evaporative filters.
    This will vary by the model you choose, but in general, the evaporative pads should be thoroughly cleaned once per season and replaced every two to three years. When clients tell me that their ventless AC is starting to smell, I know immediately that the filters have reached the end of their road.

Expectations From A Ventless Portable Air Conditioner

I briefly mentioned this earlier, but it’s important to say it again - you need to understand that a ventless portable air conditioner has its limitations and is designed for specific use case scenarios:

  • They can lower the temperature significantly in the right conditions
  • They will increase the humidity in an enclosed space
  • They require regular maintenance to keep running smoothly

From my experience, you can expect massive drops in temperatures if the temperatures are 85-100 degrees and the relative humidity is lower than 50%.

I’ve managed to drop the temps in my workshop from nearly 30 degrees on a few occasions, but those were usually during summer when the humidity was in the single digits.

On the other hand, if it’s 100 degrees outside and the humidity is higher than 70%, you’d be lucky if you manage to drop the temperature even 10 degrees.

Leave the doors open, crack the windows, and let the air flow freely.

ACLAB Note:

Over-humidification is dangerous for your health and belonging. Evaporative coolers can raise the humidity levels significantly in an enclosed space. It is recommended to get a hygrometer to monitor humidity levels. Make sure that the levels do not stay above 60% for an extended duration.

Finally, regular maintenance is key.[10]

You'll have to fill up water tanks and clean filters. If you don't wish to do this, choose the Coolzy instead for minimal maintenance.


What’s The Difference Between Ventless, Regular Portable ACs, And Window ACs?

The differences between ventless, regular portable, and window ACs are various.

Before we get into details, I thought I'd give you a visual representation of the major differences.

 

Ventless AC

Portable AC

Window AC

Ease of installation

Very easy

Easy

Medium

Refrigerant use

No

Yes

Yes

Portability

Very portable

Semi-Portable

Fixed

Energy-efficiency

Mid-High

Mid-High

Mid-High

Maintenance

High

Medium

Low

Runtime

Low

High

High

Cooling ability

Low-Mid

Medium

Medium

Cooling capacity

Low-Mid

Low-Mid

Medium

Ideal use-case

Hot and dry, open space

Hot and normal, enclosed space

Hot and humid, enclosed space

I will keep saying that ventless air conditioners are designed strictly for hot and dry climates.

They require quite a bit of maintenance, and while they are pretty energy-efficient, their runtime is limited. Since they're mostly suitable for open spaces with sufficient airflow, that limits their use case scenario. 

Unlike portable or window ACs, ventless air conditioners like the Hessaire models  do not use refrigerant.

  • Ideal use case: Patio, deck, garage, or smaller open-concept living space in a hot and dry climate.

Portable air conditioners require venting through a window or a drop ceiling.

However, what they lack in that regard, they make up for with their continuous cooling ability, which can scale over 1000 sq ft.

Portable ACs frequently come equipped with various bells and whistles, like built-in dehumidifiers, meaning they’re suitable for all sorts of climates.

  • Ideal use case: Enclosed medium-sized living or working spaces in any climate.
Window ACs work by drawing out the hot air from the room, blowing it out while simultaneously cooling the room by blowing the cool air back in.

They're very easy to maintain and operate, but unlike portable and ventless ACs, they're slightly harder to install. However, thanks to their beefier size, they can be used to cool larger spaces.

  • Ideal use case: Enclosed mid-to-large living or working spaces in humid climates.

FAQs

Is It Possible To Use A Ventless Air Conditioner In A Room Without A Window?

While it is possible to use a ventless air conditioner in a room without a window, it is not something you should do.

Since ventless air conditioners continuously use the same air, it won’t be long before the air becomes too humid, rendering it too damp to cool down while also making the space uncomfortable to reside in.

Where Does The Heat Go On A Ventless Air Conditioner?

The heat from a ventless air conditioner doesn't "go" anywhere. The ventless air conditioner cools the air in the room through the process of evaporation.

As the cooling medium (water or ice, in this case) evaporates, it absorbs heat energy from the surrounding air, effectively reducing its temperature.

Do Ventless Portable Air Conditioners Need To Be Drained?

Most ventless portable air conditioners need to be drained once every two weeks to prevent mold and bacteria growth. Due to evaporation, condensation does occur, so it’s important to keep the AC unit dry.

How Much Is The Cost Of Running A Ventless AC?

The cost of running a ventless AC isn’t too high. Depending on the power consumption of your particular model and the overall runtime, as well as the residential electricity rate in your state, you’re looking at an average annual expense of anywhere between $200 to $700.

So, Which Is The Best Ventless AC For You?

Now that I’ve explained that ventless ACs aren’t true ACs, and some even do require a vented room to prevent moisture build-up, the benefits of these products are clear. 

For personal cooling even in a windowless room, I highly recommend the Coolzy Pro as a safe, easy air conditioning alternative. For larger cooling needs, check out the Hessaire MC18M as my top choice for evaporative cooler.
My #1 Recommendation
Coolzy Pro

  • Actual Ventless "True" Portable AC
  • Unlike swamp coolers, this has refrigerant and cooling coils like normal ACs.
  • Can cool down a small space without needing to vent.
  • Does not require you to fill it up with water to work.

References: 

  1. https://jacobsheating.com/blog/seer-rating
  2. https://en.wikipedia.org/wiki/British_thermal_unit
  3. https://www.sylvane.com/swamp-cooler-buying-tips.html
  4. https://www.usgs.gov/media/images/evaporative-coolers-work-best-dry-areas-us-area-a
  5. https://www.energy.gov/energysaver/evaporative-coolers
  6. https://www.danby.com/blog/single-hose-vs-dual-hose-portable-air-conditioners/
  7. https://portacool.com/question/how-much-moisture-will-an-evaporative-cooler-add-to-the-environment/
  8. https://www.cdc.gov/nceh/hearing_loss/what_noises_cause_hearing_loss.html
  9. https://brennanheating.com/how-to-adjust-ac-fan-speed-and-why-it-may-be-necessary/
  10. https://www.nytimes.com/wirecutter/blog/do-swamp-coolers-work/
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Josh Mitchell

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Josh Mitchell
My name is Josh and I am obsessed with home appliances. From portable AC units to heaters and air purifiers, I enjoy testing, learning and using these devices to improve the air quality inside my family home.

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