You probably heard about the amazing ventless portable air conditioner, no vent or exhaust hose required to put out a window, but does such an AC even exist?
The truth is surprising but perhaps not entirely unexpected!
After all, there are many leading hardware stores that advertise this particular cooling device and I will freely admit, these ventless portable air conditioners certainly look like the free standing variety of room ACs.
However, looks can be deceptive and when those looks are backed up by the item being promoted as some kind of low energy portable air conditioning unit that does not need a vent hose, it's not surprising that buyers believe they are what they say they are.
Well, before I get started with this article, I need to dispel this particular myth about an unvented portable room air conditioner that does not need to be vented to the outside.
It does NOT exist!
Why a Portable AC Needs an Exhaust Vent Hose
All air conditioning devices that make use of the refrigeration process to chill the air (and that's ALL of them) produce a lot of hot air and excess moisture. That's what needs to be gotten out of the room being cooled by the device, or the room will actually heat up!
Fixed AC units are physically connected to outside condenser units. They extract the hot, moist air from the room and expel it into the outside atmosphere where the person sitting in their nice cool room indoors doesn't need to be concerned about it.
However, portable AC units do not have an external unit to connect to. Otherwise they wouldn't be very "portable," would they?
So, to exhaust the hot air out of the room, they make use of a flexible plastic vent hose. It can either be hung out a window or connected to a window fixing kit that looks a lot tidier but performs much the same task.
If you leave the hose in the room (or don't bother even fitting it to the back of the AC unit), the unit will actually pump out hot air direct into the room (as well as cold). That hot air will actually heat the room up faster than the AC can cool it!
I know this because I've tried it, just to see!
What is a Ventless or Hoseless Portable AC?
Sure, you've probably seen them advertised or promoted in a big hardware store as hoseless, vent free, unvented or "ventless air conditioners."
But those cooling appliances that look very much like ACs but without the hoses and/or window kits, are NOT air conditioners at all.
To give them their real name, they're called evaporative air coolers (or swamp coolers).
These devices cool the air in a very different way to refrigerant-based air conditioning appliances.
Let's look at these amazing vent-free coolers and focus on the pros and cons of getting one (or more) for your home.
Here are some examples of some of the most popular of these great coolers that are on sale right now online at the evaporative cooler specialist store, Sylvane:
Note: As a Sylvane affiliate I earn from qualifying purchases.
This seems to be the current favorite swamp cooler among Sylvane customers right now for 2023. It's a mid-power, 525 CFM (cubic feet per minute) model from popular manufacturer Honeywell's range and comes in as one of their most popular portable coolers in this genre.
I prefer not to publish prices as they may fluctuate at the store, but you can click on the image to the right to open the relevant page at Sylvane to see the current price and get all the details about the unit.
To summarize, it's an indoor/outdoor evaporative cooler with a low power consumption rating (80% less than a comparable air conditioner). It has a 3 speed fan and a low-energy "Sleep" mode of operation, making it perfect for running overnight to give you a good night's sleep in a cooler room with whisper-quiet operation.
It is rated to cool a room of up to 320 sq ft and its 7.9 gall tank holds enough water to keep it running for several hours without needing a refill. It is fitted with an active carbon dust filter that traps dust, odors and pollutants in the air for a cleaner, fresher cool breeze.
The programmable timer allows you to set and forget it for up to seven and a half hours while the handy remote makes operating the unit a breeze without having to get up out of your chair!
Click the image to see it on sale at Sylvane right now for yourself!
Hessaire MC37A 3,100 CFM Evaporative Cooler
If it's high power cooling for low running cost that you need, this free standing evaporative cooler from Hessaire can be your perfect cool companion indoors or outdoors!
With a reach of up to 950 sq ft and an output of 3,100 cubic feet of air per minute, you'd be stretched to find a better cooler for the price.
This is a swamp cooler that needs no exhaust hose because it only produces cold air without any refrigeration process or compressor.
As such it uses a fraction of the electricity of an air conditioner to keep you cool.
Simple and Effective
With few moving parts and simple automatic electronic controls for its 3 speed fan, fan-only mode and air-swing louver oscillation on or off plus the programmable timer, this unit is a joy to use.
There is no remote, just the digital display console, so there are fewer things that could go wrong. Just turn it on, set the fan speed and enjoy no-frills cooling!
This is a good sized cooler weighing in at 44 lbs without water, although it can get much heavier with 10 gallons on-board (approx 131 lbs), so just be aware of that before you try to move it when it's full!
At a height of 35in, width of 26in and depth of 18in, it is not as compact as other swamp coolers on the market, but you'll generally find that smaller units don't have anything like the high output of this one.
Big Water Tank
A ten gallon water tank, when full will allow the unit to run continuously for up to four hours.
If you want more, for instance if you're running it outdoors during a barbecue or patio party with friends or family, you can alternatively hook it up to a regular water hose for non-stop cooling as long as you need it.
Incidentally, to provide faster and wider cooling, this cooler features three-sided cooling media instead of the more common single-sided design of smaller coolers.
I don't know of any swamp coolers that run whisper-quiet, because it's just not the way they're made. A big powerful fan is always going to make some noise and there is a pretty big one in this unit.
Noise levels are claimed to be 59 dB at max power, which is actually not much different to a typical 14,000 BTU portable air conditioner.
What Sets this Cooler Apart from Other Coolers
The main difference between this and other domestic swamp coolers is its higher power output and ability to cover a much larger area, while maintaining its portability with a physical size that is not very much greater than the competition.
It has simple electronic control panel operation without a remote, which might sound like a step backward in technological terms. But is actually a breath of fresh air (pun intended) for people that prefer to not have to wrestle with complicated high-tech remote controls that they often seem to misplace!
This is the latest model in the Hessair range at time of publication of this article. It has evolved from its predecessor with simple operation basics for a simpler, yet still highly effective low cost cooling solution. It features improvements in air flow, cooling media through-air dispersion, automatic airflow oscillation and multiple fan speeds for more cooling options.
Pros and Cons
Pros: On the plus side, this is a low cost cooling solution for people that live in an evaporative-cooler-compatible climate, which is predominantly dry air during hot weather.
Cons: On the minus side, this cooler will not be effective in humid conditions, as humidity reduces the cooler's ability to evaporate moisture into the air to produce the cooling effect.
This is a Swamp Cooler
Just remember that a swamp cooler will not be effective if you live in a humid climate. It will not perform like an air conditioner to cool a whole house, but is best used for spot cooling or keeping a single room cool when the air is naturally dry as in desert or semi-desert locations.
If your climate conditions are right and you like the idea of being more environmentally friendly while keeping your energy bills low, you can buy this cooler online at Sylvane. Click the image above right to visit Sylvane for more details.
Another popular indoor swamp cooler is the Honeywell 470 CFM indoor portable evaporative cooler and humidifier that comes fitted with a carbon dust filter for really clean, dust-free cool air.
This model is less powerful than the two coolers I've covered above, but for the energy-conscious it's very frugal, using up to 230 watts to power its 470 CFM airflow that can effectively cool a space of up to 250 sq ft.
The large 5.3 gallon tank will keep this cooler running for up to 8 hours on a full tank of water and it has a top loading ice compartment for even colder air if you need it. There is a low water alarm to warn you when it's getting close to running out.
The three speed fan has oscillating louvers creating what the manufacturer calls "three rhythmic wind modes" for a really versatile way of staying cool in the heat. It also has an energy saving timer plus an adjustable humidification dial that lets you control how much humidity is output into the air.
This model also has a remote control for convenience coupled with a really easy to read display to make operating it a breeze!
Click the image above right to visit Sylvane and get all the details plus the surprisingly affordable price of this model.
How Do Swamp Coolers Work?
These coolers use a very simple method to cool the air. That is to draw room temperature air through a damp, sponge-like medium, evaporating the moisture which chills it. Then to force the now cold air out the front of the unit to cool the whole room.
Some ventless portable air conditioner models have a simple pump to keep the medium wet, while others rely on gravity, which works surprisingly well.
Most models allow you to add ice to the water reservoir tank in the unit to make the expelled air even colder.
Let's look at the advantages and disadvantages of this very special type of cooling device:
First of all, the good side, or pros of owning and running a swamp cooler:
All the work is done by a simple fan, which uses very little electricity (typically 100-200 watts) compared to the energy sucking compressor and refrigeration process of a comparably sized portable AC (typically around 2,000 watts). That makes swamp coolers very economical to run indeed compared to AC, which is good news if you're on a tight budget.
It's also good news if you are environmentally aware and considerate because when you use less electricity, it means less needs to be generated. That means less fuel needs to be used, with lower pollution levels and less damage to the ecology.
Because there is no refrigeration and heat exchange process at work inside these appliances, there is no hot air produced.
That means there is no need for a vent hose (or in some cases dual hoses) to hang out a window, which is doubtless the main point that drew you to read this article in the first place!
So far we've seen some great plus points for these awesome cooling appliances. Now let's look at the minus points:
The major flaw in this method of producing a cooling breeze is that is doesn't work so well in humid conditions. The reason is pretty simple:
For cooling by evaporation to be effective, the air needs to be "dry" so that it can accept the cold moisture (water vapor) that is fanned out of the cooler. As the level of moisture in the air rises (high humidity) it gets to a point where it becomes saturated with moisture and can't hold any more.
At that point, the cooling effect of air being blown through the moist medium is reduced because it can no longer be effectively evaporated into saturated air. One solution is to open a window to allow fresh, drier air to circulate in the room, but if the outside air is also very humid, the problem persists.
For this reason, evaporative coolers are not recommended for people who live in areas that have very high humidity through the hot summer months. In that case, traditional AC needs to be used (with doors and windows closed) to effectively cool a room or a building.
Refilling the Water Tank
Another disadvantage, although this is more of an inconvenience than anything else, is that the water reservoir tank needs to be refilled periodically to stop the medium drying out and ceasing to cool the air. Many ventless portable air conditioner models come with large capacity tanks (several gallons) so they only need refilling once a day or so.
Very large units that are also suitable for outdoor use come with a hose attachment so you can hook up the water reservoir to a standard water hose and simply turn on the faucet and have a constant supply of water!
Buy an Evaporative Cooler Online
There is more good news for those folks living in areas of low humidity that want to save money on their cooling costs. You can buy some of the best portable evaporative cooling units online at great prices and in certain circumstances, low cost or even free delivery!
It's not such great news for the majority of people living in a humid climate, where the only realistic alternative is a regular AC. But when push comes to shove and you need some respite from the oppressive humid heat, there is a newer, more efficient and economical type of portable self evaporating air conditioner available like this highly efficient type of model (you can read about them by clicking that link).
However, since the mission of this article is to promote energy saving cooling systems and solutions to people that can use them, we can recommend some of the best, low-running-cost swamp cooler models available today (see my Sylvane picks above).
If you want to know more about how evaporative cooling works, see this Consumer Energy Center article.
Last Updated: March 20, 2023