8 Best Ventless Air Conditioners

Ventless Portable AC Units Compared

What To Look For In Ventless AC - A Buyer's Guide

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.

Learning this will help you find the best air conditioner for you and might even save you a few bucks, so please read carefully.

Cooling Capacity Vs Coverage Area

The first thing you’ll see when shopping for a portable air conditioner (or even a mini-split like Pioneer WYS012A-20) 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 that when shopping for a ventless air conditioner.

The cooling capacity of ventless portable air conditioners is simply shown by its coverage area, which depending on the model, could even be as high as 1500 sq ft (as is the case with Hessaire MC61V).

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.

Naturally, you'll want to take this 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.

Climate Conditions

Your region's climate will greatly influence how efficient ventless air conditioners can be.

High humidity and high heat areas, for example Miami, will have the least efficient use of these fans, whereas hot, dry areas, such as Phoenix, could benefit from it.[4]

As you can probably figure out, the issue here is the high temperature and that the water warms up quickly because it's hot outside, but rather because it's virtually impossible to cool down humid air by adding moisture to it.

 You see, ventless air conditioners or evaporative coolers lower the temperature by running hot and dry air over a water-soaked cooling pad to cool it down. What happens here is the heat from the air causes the introduced water to evaporate, which in turn absorbs heat, effectively cooling the air the AC spews back out.[5]

On the other hand, if the relative humidity is already high (greater than 65%, for example), there’s essentially no room for cooling to occur because the air is already saturated with moisture.

Use Case

A ventless air conditioner is not your regular AC or even a portable air conditioner.

 Unlike other portable units, an evaporative cooler does not come with an exhaust hose, meaning it won't be able to pump out the warm air and bring in fresh air into the room.

And, I know what you’re thinking, unless it’s a dual-vent portable AC - most of them won’t do that either.[6]

We're not talking about negative or positive air pressure or things of that nature. We're talking about which use cases evaporative coolers can be used for because, truth be told, they simply can't do what most people want them to do.

The ideal use cases for a ventless air conditioner or an evaporative cooler would be:

In other words, the ideal scenario is wherever there’s a continuous supply of fresh and hot air to be cooled.

In the same way, a ventless unit isn't ideal for other uses (for example, small, enclosed living rooms or bedrooms) because it will spew moist air back into the room, creating a damp and humid environment in a matter of hours.[7]

Now, I’m not saying ventless units like Honeywell CO30XE can’t be used in small enclosed spaces because their cooling performance sure won’t disappoint if you stick them in a bedroom - it’s just that there are better options out there - like most portable air coolers.

Air Flow Capacity

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).

What this means in practice is that your portable air conditioner with a higher CFM can move more air over a certain period, thus improving the overall cooling power and cooling performance.

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

While it may seem like a good idea to get the biggest, most powerful ventless portable AC, such as Hessaire MC61V - that’s not always the case.

Not only will a high CFM ventless air conditioner be somewhat uncomfortable to be nearby, but it could also be quite noisy, cause some draft, and be too costly to operate.

Although truth be told, the latter isn’t always necessarily the case.

As you can see from the list, Hessaire MC61V has a CFM of 5300, and the Portacool Jetstream 230 has a CFM of 3600, yet Jetstream draws twice as much electricity.

Low Noise Levels

A prerequisite for any air conditioner, whether a ventless air conditioner or a traditional air conditioner, is that it is quiet.

 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.

Generally, most ventless portable air conditioners run at 50-70 dB, which may not seem like a lot.

For reference, an average conversion takes place at around 60 dB.[8] That means anything higher than that can be disruptive and annoying - like the issue with Honeywell CO30XE.

So, if possible, go for a unit closer to or under 60 dB, such as Honeywell CS10XE or Hessaire MC18M.

Tank Size And Runtime

Most ventless air conditioners can't offer consistent cooling like central air conditioning systems. Instead, they 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.

So, how do you choose? What should you expect?

As you can see from the products listed above, a tank can be as small as 2 gallons to as big as 30 gallons. On average, you'll be looking at 4-8 gallon tanks in most cases, as those strike a great balance between portability and usability.

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.

You’ll often see people complaining about the runtime and saying things like “it’s only four hours” and things of that nature, but that’s how it goes with ventless air conditioners.

They simply aren’t made to run carefree, and while it may be a hassle filling up the tank twice a day - that’s just the way it is.

If you want continuous use from a ventless air conditioner, you’ll need a hose so it can have a continuous supply of fresh water. As you can imagine, that basically limits these things to outdoor use.

Also, portability is out of the question if you hook it up.

Finally, if you’re considering getting a ventless air conditioner to keep your bedroom cool all night long - you probably shouldn’t because you’re highly unlikely to find one that can run for more than 8 hours, and even if you did (which I did with Honeywell CO30XE ), it’s possible you’ll run into some other issues.

Fan Speed Options

In most cases, ventless air conditioners will come with a few different fan speed settings - low, high, and medium.

And in my opinion - fan speeds are a lot more important than many seem to believe.[9]

Picture a scorching hot day…

 You'll want that fan cranked up to high to get as much cool air circulating as possible. But on a slightly warmer day? A fan on "Low" can keep you just as comfortable.

Another thing to discuss here is actually "Fan-only" mode - the cooler's chill setting, which turns off the water pump and just runs the fan for a nice breeze with no extra cooling.

Control Methods

Most ventless air conditioners are incredibly easy to control and use.

As you saw earlier, a ventless air conditioner can be either controlled manually (like my top pick), using a knob you can turn to select the cooling mode, or a remote controller (like it was with, for example, Honeywell CS10XE), which you can use to do the same.

More often than not, you’ll be able to choose between cooling and fan-only mode, as well as control the fan speeds, as previously mentioned.

Rarely will you be able to integrate ventless air conditioners with smart home gadgets or your phone, as those features are usually reserved for central air conditioner units.

Long-Term Reliability

I’m sure you’ve probably read more than one review about a ventless air conditioner dying after a year of use, and yes, all of those are true and very real - just go back to Portacool Jetstream 230.

A rather staggering amount of ventless air conditioners die early on, which is both the result of crappy manufacturing and improper use.

Thankfully, there are three neat tricks you can utilize to get yourself a reliable, long-lasting ventless portable air conditioner.

Companies that stay in business for years (for example, Hessaire) usually offer good, reliable products - so check them out first. Also, skip Facebook Marketplace and sketchy resellers and buy through tried and trusted channels.

Secondly, if the manufacturer is willing to give you a money-back or free-repair guarantee for two or three years - they’re probably sure their product is going to last.

The third point is the cause of most problems.

 People usually want the utility of a portable air conditioner and the performance of a central air conditioner system while paying ventless air conditioner prices.

That simply doesn't work.

 These things are made to work from time to time and give you instant but short-lived relief in case things get hot.

Chilling your entire house or even a room for the entire summer with one of these is simply not an option.

Also, people are forgetful, and it’s not uncommon for them to leave a ventless air conditioner running with an empty tank. And, if your unit does not have empty tank detection - there’s a good chance you’ll end up without an AC.

Size and Portability

To be completely honest, ventless air conditioners are actually what portable air conditioners should be.

They’re not bound to exhaust hoses, windows, and drop ceilings, and they’re super easy to move around, as the only thing they require is water or ice and electricity.

So, as long as there's an electrical outlet nearby - you’re good to go.

Size-wise - there’s no such thing as the best portable air conditioner, as the “best” will largely depend on what you need this thing for.

That said, these things can be really small and compact, like the Evapolar EvaCHILL, which comfortably fits on a bedside table; and be big and bulky, like Portacool Jetstream 230, that's just barely portable.

If you plan on moving your ventless air conditioner around from room to room, then yes, both size and portability matter.

If you just plan on sticking it on a patio or in a workshop as I did - I wouldn't worry about either.

Ease Of Maintenance And Use

In most cases, ventless air conditioners will be very easy to both maintain and use.

Using ventless air conditioners is usually incredibly simple.

You’ll either deal with a knob that you turn on and off, alongside a few fan and cooling modes, or you’ll get a remote control where you’ll simply press a button and be done.

Maintenance-wise, you will need to do two or three things.

Refilling the water tank is not an option, as ventless air contenders need water to cool down hot air.

As we said, most of the time, you’ll have to refill the water tank every three to six hours, and I strongly urge you to stay on top of this.

Some ventless portable units will have an alarm or an auto-off switch to prevent the AC from running without water, but if there isn’t one - I suggest setting a timer or an alarm on your phone.

Also, cleaning them regularly prevents mold and bacteria from developing, so stay on top of that, too.

As for air filters, all of the best ventless air conditioners will have one (charcoal or carbon filters, as you saw with Honeywell CS10XE) that you’ll need to wash or replace every once in a while if you want them to filter the air and prevent odors.

To be more precise, if you want the filters to have any purpose - wash them every two weeks, and replace them every year or so - depending on what the manufacturer recommends.

As for the “use fan-only mode” recommendation, this is mostly a preventive measure/maintenance method to dry out the filters to prevent bacteria growth.

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.

That said, there are three things you need to keep in mind:

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%. On average, you can expect 20-degree drops in those conditions.

And just FYI, 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 temps to the high 80s.

Secondly, these really aren’t meant for prolonged use in enclosed spaces. Considering these keep recirculating the same air over and over again, humidifying it over and over again, it’s more than possible to end up in a super damp room in a matter of hours.

Therefore, proper ventilation is a MUST.

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

Finally, regular maintenance is key.[10]

Filling up water tanks and cleaning filters is something you'll have to do. If you don't wish to do it - ventless air conditioners aren't for you, and you should probably get yourself that mini-slip from Pioneer I mentioned above.

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.

Seeing this mini table, it becomes obvious that these share a few similarities but also a few differences, so let's go over each.

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 quite limited, and seeing how they're mostly suitable for open spaces with sufficient airflow, that limits their use case scenario. Also, they don't use refrigerants like the other two.

Portable air conditioners, despite their name, aren’t all that portable because they often 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.

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

Window air conditioners are fixed ACs that, as you can tell from the name, fit inside of a window opening.

They 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.

People Also Ask (FAQs)

Do ventless air conditioners work?

Yes, ventless air conditioners work, and depending on the conditions, they can lower the air temperature by up to 30 degrees. Despite that, they shouldn’t be your go-to solution unless you live in a hot and dry climate, as humidity greatly diminishes the effectiveness of these air conditioners.

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.

Conclusion

To sum up - are the ventless AC units I mentioned above worth it?

Totally, and I’ve listed the best options. As long as you’re fully aware of the factors at play, any of these will do the trick.

Whether you go for a budget-friendly option like Hessaire MC18M, which is my personal favorite and an air conditioner I’ve been using for years, or a mighty option for your business, such as Portacool Jetstream 230 - I don’t think you’ll have a hard time finding what works for you, if you’ve taken the time to read this guide thoroughly.

In fact, I’m sure you’ve already found yourself a new ventless air conditioner!