How to Install a Portable Air Conditioner [+Vent Properly]

Written by: Paul Cathro

Updated on: December 23, 2022

Learn how to get your portable air conditioner up and running in no time with our simple guide. This is portable air conditioner installation done properly.

Delonghi Pinguino remote control

Portable ACs are pretty straightforward to set up and it shouldn't take longer than 20 minutes for cool air to start circulating through your home.

In this guide, we explain the steps that are needed to install a portable AC safely and correctly.

We'll cover the different venting options available.

Including how to install a portable air conditioner in a sliding window and the other options available to you.

Positioning: Where to Place Your Portable AC

This first step in portable AC installation is crucial and often overlooked. 

If you want your AC to run at its most efficient best then make sure you tick these boxes.

  1. Proximity to power - this one is perhaps the most obvious and that is that your AC will need to be close enough to a power supply. You don't want to be using extensions for powerful appliances like these. It can be a potential fire risk. The leading portable air cons will give you a cord length of at least 6 feet but be sure to check this before you buy.
  2. Proximity to venting - this depends on the method of venting being used (we cover all options later in the guide). But if you are venting with a window kit then you'll obviously want to be close to a window. Most window kit hoses will allow around 6 feet of distance. You'll want to keep the hosing as straight as possible and the shorter the better.
  3. Draining - again this depends on the method of draining being used. There are generally 3 drainage options and the top portable AC units will allow you to use all of them. If manually draining then if mobility is an issue for you then you might not want to be far from a kitchen or bathroom to dispose of the water. If automatically draining using a hose, then you'll need to be within around 20 feet (dependent on model) of the place where you plan on keeping the end of the hose. The third option is self evaporation which isn't affected by the positioning of your portable AC.
  4. Surface - these devices can be quite heavy and should only be used on a hard, level surface. They should always be placed on the ground and never on tables or anything like that.
  5. Clearances - according to most manuals you'll to make sure there's a minimum of at least 20 inches of clearance around the air inlet and outlet. Ideally, you'll want to make sure that the outlet has much more than this for unobstructed fan cooling. 

Related: How do portable ACs work?

Venting: How to Vent Using a Window Kit

Window kits are usually straightforward to set up but if you have old windows you might have more difficulty.

In fact, for lots of people window kits are not even possible. If you don't have access to a window or if you have casement windows (those that open outwards on hinges like a door) then you should skip to the next section.

Otherwise, now we're going to explain how to install a portable air conditioner in a sliding window.

Step 1: How to Fit For Your Window

Window kits are adaptable to windows that slide up and those that slide to the side.

The diagram below illustrates the set-up for a dual hose air conditioner. A single hose model will follow the exact same process using just one exhaust hose.

installing a window kit for portable AC

If your window slides up then the window kit will fit in the bottom of your window frame. Simply slide the window open completely, place the kit at the bottom, and then slowly bring the window down to meet the kit.

You'll follow the same process for a window that opens to the side.

A potential sticking point here is when the window opening is less than the minimum length of the window slider kit. 

In this case, you'll need to cut the window kit to make it fit. 

But don't fret, this is easily done. Simply trim the slider part (the side opposite the exhaust hole) with a utility knife.

With the window kit in place and fitting snuggly you can then screw it in to secure it. However, this step is optional and you may not want to secure it like this if you plan on moving your portable AC regularly.

If your window kit doesn't come with any weather stripping to plug potential air gaps then it's worth buying your own. Weather stripping (it's like a foam seal)  is really cheap and easy to apply and it will plug air gaps that allow warm air to easily pass into the home.

Security is often an issue for those that live on the ground floor. If this is a concern of yours then special security locks are available that are designed to secure portable air conditioner window kits like these.


In the unlikely event that your window opening is larger than the maximum length of the window kit then you will need to fill the gap with something reasonably strong that doesn't have air leaks. Plexiglass (perspex) or thin wood work well. It's really important to plug any air gaps too.

Step 2: How to Connect the Vent Hose

Steps to Install AC window kit

The first step is to connect the adapters to both ends of the venting hose (if they didn't come attached).

You'll then want to attach on end to the portable air conditioner.

Remember the unit should be positioned in close proximity to the window but with a minimum of 20 inches of clearance between it and the wall.

The final step is to attach the other end of the exhaust hose to the window kit. Ensure both ends are secured firmly in place.

For the most efficient ventilation, the hose should be as short and straight a possible. Make sure there's nothing nearby that might be pushed or pressed against it to restrict its efficiency either.

Related: We recommend the quietest near silent portable air conditioners in our popular guide.

Venting: How to Vent Without a Window

Sometimes with portable AC installation window venting isn't possible or just not desirable for whatever reason.

Thankfully, there are still various options for venting a portable air conditioner without a window kit.

Option 1 : Vent Through a Sliding Door

Similar to venting through a large window, using a sliding door just requires a specialist door kit or a regular window kit and more filler to make up the larger gap.

Honeywell make a great sliding door kit for their portable AC models. You can see it here.

Like with windows, Perspex or Plexiglass makes the perfect filler for the air gap if you're planning to stick with a window kit. 

An issue with door kits is actually using the door. It's a bit of a pain to have to move the kit each time you want to access the door. Plus you're inviting all that warm air into your home every time you do remove it. It's a definitely a dilemma worth considering.

Option 2: Vent Through a Drop Ceiling

If your home has a drop ceiling then this option is open to you.

drop ceiling venting for portable AC

It's one of the more complicated options that might require the help of an HVAC technician if you're not confident with DIY. You can use a specialist kit or piece together the components yourself.

You need to be careful when making a hole in the ceiling that you don't interfere with any pipework or electrical wires. Once you've made a hole you need to seal it with silicone.

The hardest part is attaching the hose to the ceiling. It's for this reason that most people use specialist ceiling vent kits and hire a professional.

Since you're venting your portable air conditioner in the ceiling space or attic you should monitor the temperature and level of humidity. You risk creating mold if it's too warm and moist up there.

Related: Don't miss our Delonghi Pinguino portable AC review.

Option 3: Vent Through a Wall

Venting your portable AC though an exterior wall is always an option but not always an easy one to implement.

It's often the last resort as it's a permanent solution that limits the portable nature of your air conditioner. It can also be unsightly to have a large hole in the wall of your home.

Certain types of wall are difficult to drill through and it's advisable to get professional help. Any errors are difficult and costly to reverse.

Again it's imperative that you find a safe spot to drill that's not going to weaken the wall.  You don't want to hit a stud or beam. You also want to avoids pipework and electrical wires.

Reinforced steel walls or particularly thick brick walls for example, would require a professional to drill through. Ideally, you'd want to use a thin concrete or plasterboard wall.

If you're really lucky there might already be a usable hole that's used for something like a laundry vent. 

Portable AC vented through a wall

Option 4: Vent Through a Dryer Vent

This is an option that makes great use of what's there and saves extra holes being created. However, dryer vents are usually smaller than AC exhaust vents and for this reason HVAC technicians might adviser against choosing this option.

It's important that the warm exhaust air can travel through the hose unrestricted or it's going to affect the efficiency of your portable AC.

If you choose this option (only after consulting a professional) it's important that you monitor the efficiency of your AC to make sure it's not being impacted by a throttled exhaust hose.

A serious fire risk might also arise if your dryer is unable to vent its hot air properly.

Option 5: Vent Through a Chimney

If you have an unused chimney then this is a great ready made option for venting the exhaust hose of a portable AC unit.

If your unused fireplace is large enough then you can even place your air conditioner directly underneath the chimney where the fire would otherwise be. This is a great way to save space and you can extend the hosepipe further up the chimney to dispose of the hot air more efficiently.

Is it Essential to Vent a Portable AC Outside?

The short answer is yes. 

However, there are caveats.

When using an air conditioner in its main mode of cooling then yes it must be vented outside. If the hot exhaust air is not disposed of outside then it only serves to warm the room that you require to be cooled.

This means your air conditioner will not run efficiently and will need to work harder to keep your room cool. This would be an expensive mistake to make.

But, these devices also have 'fan' and 'dehumidify' modes too. When using these modes the venting is not necessary.

Just remember that when dehumidifying there will be lots of waste water collected that needs to be drained.

About the Author Paul Cathro

Paul is an ex-HVAC engineer with 5 years 'in the trade'.

He acquired in 2022 and aims to make it the internet's most comprehensive HVAC resource for small homes in the next few years.

You can learn more about Paul's story here.

Browse his published work on the website here.

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