5 Best Window Seals For Portable AC (For Easy DIY)

Are you still duct taping your portable air conditioner’s vent out of the window?

Don’t get me wrong – it is a good practice. Knowing how to properly insulate the space your portable AC hose makes in the window frame will:

  1. Make a mobile air conditioner more efficient.
  2. Drop the temperature quicker.
  3. Save you a few bucks on the electricity bill.
  4. Keep the mosquitos out.

5 Best Window Seal Kits For AC Unit

Most owners of air conditioners are not explicitly aware of the range of options you encounter when wanting to buy a window cover for your portable AC.

That’s why we’ve made it easy. We looked at 10s of different kits and distilled which 5 are the best. Here are our editorial Top5er picks for the best window seal kits for portable air conditioners:

AC Window SealHOOMEE kitAirly 'Keep Cool' FitFirst kitMorningRising kitJOYOOO kit
hoomee ac window sealairly best window seal for ac fitfirst 158 inch window seal morningrising window enclosure joyooo airlock
Max. Length:157''158''157''158''158''
Instructions:Crystal ClearClearClearLackingLacking
Quality:4.9 out of 5 stars4.9 out of 5 stars4.8 out of 5 stars4.2 out of 5 stars3.9 out of 5 stars
Rating:4.9 out of 5 stars4.8 out of 5 stars4.8 out of 5 stars4 out of 5 stars3.8 out of 5 stars
Top5er status:Best SellerBest QualityBest BudgetCheapestReliable
Availability: Check Price Check Price Check Price Check Price Check Price
The problem is how many of us still seal a window (including the sliding glass window and even sliding doors) with, well, a duct tape.


Because there is a much better and more convenient way of ensuring the hot air from a portable air conditioner will fully be released into the environment.

We are, of course, talking about the modern window enclosure for portable AC.

Note: If you have a problem with cold air leaking into your house in the winter via AC hose, you should consider checking out our article about the best air conditioner covers.

What Is A Window Seal For Mobile AC Anyway?

All portable air conditioners need a vent for the hot air generated by the AC to be vented out of your house, flat, you name it.

Windows seals that are designed specifically to accommodate AC vents are nothing new, really. They have been around for about a decade and they are there to do 1 job and 1 job alone (or maybe 2):

  1. Insulate the portable AC exhaust that goes out the window.
  2. (Should look great).
In short, a window seal is basically the best way of how to vent your mobile AC out of the window. It should fill up all the nooks and crannies.


With style. The design of these tight enclosure seals for window frames should be to your liking. After all, you’ll likely be looking at the window and the seal strapped (with Velcro tape) on it for the whole summer.

So if you have a portable air conditioning unit, why didn’t you install a window cover for PAC 10 years ago?

How To Install A Seal For AC On The Window – Simplified

There is a simple reason why we’re only now experiencing a boom about window seals.

No, it’s not the duct tape method of sealing windows that went out of fashion.

It has everything to do with how easy modern window seals can be installed.

10 years ago you needed an AC expert to strap a window seal very carefully on the window frame. We ordinary people just found it too complicated and the window seal installation was bothersome.

In the last years, however, there is an emergence of the AC window seal kits. Yes, kits. Something an ordinary fellow can use to install the window enclosure in a DIY way with a simple use of Velcro tape.

The kits usually include everything you need to install the seal and insulate windows out of which the AC vent goes. And they cost around $20 in total.

However, one thing in mind when picking the best window enclosure kit for a portable air conditioner is how clear are the instructions written.

This is not basic and ugly duct tapping of the windows. You get quite a few pieces with every one of these kits and thorough and clear instructions are essential in order for you to properly install it.

You wouldn’t like for the window insulation to start peeling off after a week because the instructions were not clear about how to tightly seal the insulation tape, right?

No. 1 Window Seal Pick

No. 1 HOOMEE Universal Window Sealer For AC And Tumble Dryer

The best window seal is the HOOMEE universal Velcro-based seal. What is more, being universal, this can cover the window frame now just when using a portable AC unit but you can use it for tumble dryer as well.

One thing that HOOMEE offers is the variety of window seal sizes. A normal seal for the AC vent can be attached to a 157” or 158” window. You can have two problems with that:

  1. Window is too large. Whatever you do with the AC seal, there is no way to stretch it beyond 158-inches or so.
  2. Window is small. You can apply the normal window seal on it but much of the material such as Velcro tape you buy will go to waste. If you have a 50-inch window, shouldn’t you buy a smaller AC unit window seal for a lower price?

Additionally to standard size 400 cm seal, HOOMEE also offers two other versions:

  1. The big window enclosure for AC. Can fit a window up to 560 cm, or 219 inches.
  2. The smaller window seal. Will fit a window of length up to 300 cm, or 117 inches. It costs about 5 bucks less and you’ll have less Velcro waste to worry about.

Both with the small, normal or big version, you can fit not only one but two or more air conditioning vents (or you can have one from the tumble dryer and one from AC):

big window sealer for AC
Fit 1, 2 or more vents from AC or tumble dryer through the HOOMEE sealed window cover.

This makes the HOOMEE seal the most versatile on the list.

You might have some problems with the instructions; there are somewhat lacking the details. However, they have a nice short video of how to install the seal on the window.

In every case, keep one thing in mind when applying the Velcro tape to the window frame – it has to be applied on a dry, smooth and flat surface. If you can find such a surface, you shouldn’t have any problems with seal installation even without the step-by-step instructions.


  • Universal: For AC and tumble dryer.
  • Only one with various sizes: small, normal, big.
  • Can fit more than one vent easily, if the window allows it.
  • Is the best selling universal window seal.


  • The installation instructions are not as details as with other seal kits.
  • Can hardly be fit with a skylight.
  • Not appropriate for sliding windows.

No. 2 Window Seal Pick

No. 2 Best Window Seal- Airly ‘Keep Cool’

There is not a window seal on the market, for AC, tumble drier or anything else, that would be as simple and fully functioning as the Airly seal.

Their motto of ‘Keep Cool’ translates very-well into the seat itself. The zipper for the enclosure and adhesive fastener make the installation process very simple, and adhesive fastener just helps with that.

Apart from doing the job (and it does it well), the Airly airlock actually looks nice on the window.

Truth is that many of the seals on the market are not exactly visible appealing. Made out of plastic or low-grade cotton, they are not a much more pleasing sight than a window tapped all over by duct tape.

Here is how Airly window seal looks like when fully installed on a window:

seal for ac went
Airly seal perfectly fits the vent and the window, and it actually looks nice while doing so.

Does the Airly window seal fit most windows?

Airly can be installed on all windows with a maximum window length of 158 inches. That is quite an above-average max. window length for an AC seal and it will fit almost any window. Of course, if you have a window that is longer than 158, Airly won’t fit on it. However, given that you have to deal with a mobile AC unit, you can easily just put in under another smaller window in order to use the best window seal.

The essential part of every window kit for AC are the instructions. Without clear instructions, it’s hard to Velcro tape your way around the window, and mistakes can happen. Here are the step-by-step instructions for Airly that pretty much everybody can use:

window seal installation instructions
Simple step-by-step instructions for installing the Airly window seal for portable AC.

As you can see from the instructions on how to install the window seal, it can be pretty straightforward. Paste the Velcro tape, trim the edges, make sure that the seat aligns with the window frame, and unzip.

The installation shouldn’t take more than 10 minutes and it will actually look like a proper installation job.

One reviewer pointed out that, despite the smoothness window panel installation, the Velcro tape should be a bit more ‘sticky’.

A lot has been said about the stickiness of Velcro; for some needs, it is too sticky and for other, it should be stickier. In the world of window seals, we found that Velcro tape is pretty much the standard way of attaching the seal to the window frame and every seal for AC uses one. So, no way around that using Velcro (don’t resort to duct tape, of course).

All in all, if you’re looking how to seal space around the portable air conditioning vent, you’ll find Airly simple enough to use and tight enough so that no hot air (or mosquitos) will enter the room from the outside.


  • Appealing to the eye materials.
  • Zipper and Velcro tape included.
  • Step-by-step instructions can be easily followed.
  • Everyone can install this by him or herself.
  • Clear winner as the No. 1 window seal.


  • Velcro should be a bit more ‘sticky’.
  • Not appropriate for windows with a total length above 158 inches.

No. 3 Window Seal Pick

No. 3 Fitfirst Window Seal Review

When it comes to blocking the draft from a mobile AC unit via the window, Fitfirst does come in handy.

It’s easy to install and made out of high-quality materials that Fitfirst seal for the window is made out of giving it a nice and clean look.

What length of a window can you install Fitfirst on?

It should be 157 inches long or shorter. Also, be aware that it can be a bit of a stretch attaching it to any window that is 150+ inches. Yes, with a bit of trouble it can fit a 157-inch long window frame, but it will require a bit of sweating on your part.

Luckily, after it’s installed (photo below), your air conditioner will be more efficient and will readily cool you down and reduce your sweating:

fitfirst window seal assessment for air conditioning units
Fitfirst window seal when installed on a short-length window.

What kind of window can you install Fitfirst seal on?

Pretty much any window will do that is not too big. If the window near your air conditioner is too big, it might be a good idea just to move the AC unit under the other window. It’s portable, so that’s quite easily done.

Basically, the illuminated white fabric window seal is made out of lightens up the whole room. If you’re looking for air conditioners that work with a skylight, this light-my-room feature can be quite amazing to see.


  • High-quality materials are durable (despite the weather).
  • Tightly seals most types of windows.
  • Can illuminate the room substantially (white fabric + sunlight).
  • Almost comparable to No. 1 pick but a buck or two cheaper.


  • Has simple but not very thorough installation information.
  • Not as thick protecting fabric as Airly.

No. 4 Window Seal Pick

Cloth Window Sealing Place By MorningRising

MorningRising cloth seal for windows (if you need to put the AC hose through the window) is another good example of how simple and easy it to DIY the window seal.

Their window seal kit comes with everything you need to fill all the space around a portable air conditioner’s hose, and you can do it by yourself in less than 10 minutes – but do take 20 minutes in order to be as accurate in laying the Velcro tape around the edges of smooth-surface window frames as possible.

It can be used as a single-vent or double-vent air conditioner. However, the limiting factor is the type of window. It can’t be mounted on every kind of window; it is most commonly used on tilting windows but if want to install it on a basement window, skylight or balcony door, you’ll have too many problems with keeping it all intact.

In short, it can’t be used on these types of windows. It’s best to use it exclusively on tilting windows and you have to use a zipper in order to tighten the space around the vent like this:

tilting window how to seal it
Zip the seal tightly around the AC hose. Example: MorningRising seal.

Some AC units can also be stationed near sliding windows or doors. While No. 1, 2 and 3 pick on this list can accommodate such windows (albeit with a bit of struggle), the MorningRising cloth seal specifically informs their potential customers that the product cannot be used on the left or right sliding window or doors.

Nonetheless, this is the cheapest seal for a window on the list and is our budget pick.


  • Can be installed in 10 minutes.
  • Perfect for tilting windows.
  • Can accommodate one-tube or two-tube air conditioners.
  • Is the cheapest window seal.


  • Can’t fit on sliding windows or doors.
  • Can’t use the seal on a skylight.
  • Made out of cloth; can get a bit damp.

No. 5 Window Seal Pick

JOYOOO AirLock For Mobile ACs

If you’re looking for a reliable window seal to prevent the hot air from being released in the room the air conditioner is located in, you can opt to pick the JOYOOO AirLock.

Comparing it with other seals, two things stand out:

  1. Little info about how to install it (you’ll need to have a bit of technical inspiration to DIY it).
  2. Durable. If you manage to put it on the window, it will stick there for quite a long time; it is very well made which makes it quite durable.

Instructions are essential when putting a seal on the window; most of the seals come with step-by-step instructions. AirLock JOYOOO, however, lacks information to such a degree that somebody who bought it actually asked on Amazon how to install it.

That’s not a good sign.

However, nobody can deny how long the window seal can last, and that is the main reason that JOYOOO AirLock is included in the Top5er list.

It has some versatility as far a the length of the window is concerned (max. length is 158 inches). You should be a technical type to use the tape it without the manual but if you do a good job, the durability of the materials will ensure that you’ll be able to use it with the air conditioner for years.


  • Most durable.
  • Standard window kit is, well, quite standard.
  • May present a small technical challenge.


  • Lacking some essential instructions.
  • … how do you install this thing, really?
  • You’ll need technical skills to install it.

Which Is The Best Window Seal For You?

Let us know in the comments. Even if you use duct tape, you can share a photo or two. Some people use foam to seal the space between the AC vent; would be interesting to see one of those as well.

Keep cool.

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4 thoughts on “5 Best Window Seals For Portable AC (For Easy DIY)”

  1. Is there anything like this being made or on the market for bottom opening sliding windows? (Windows sliding bottom to top). I’ve looked everywhere but Can’t seem to find anything. Thank you.

    • Hello Debra, that’s a good question. I’ve also had problems with finding some kind of seal for bottom opening on the sliding windows. The best I can tell there is nothing remotely appropriate on the market for that; I think velcro can be your best friend here.

  2. Hello I’m looking for a window sealer but I’m not understanding the measurements it says a 158 inches how long is that? I only need it for a window that’s 35 inches. Could someone please help thanks

    • Hello Kris, the 158 inches is the maximum allowed length. You can install any portable AC window seal on a 35-inch window. However, if you have an enormous 200-inch window, you would be out of luck. Hope this helps.


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