Portable Air Conditioner Venting Options (With and Without a Window)

Many people are interested in buying a portable air conditioner for cooling but are unsure how to vent it. To end all confusion, we will address the basics of how a portable AC works and all available venting options, including a windowless room. Stick around to find out the importance of ventilation, which method we prefer, and how to get the best out of it.


The primary function of a portable air conditioner is to cool a room by extracting heat from the air, and venting is an integral part of the process. It removes the moisture that would otherwise affect the room temperature. Without proper ventilation, hot air will remain trapped inside, preventing the room from getting cold. As such, the less humidity buildup in a room, the cooler you will feel.

Now you have a basic understanding of why we need to vent out the hot air. Next, let’s explore the few venting options for a portable air conditioner with and without a window.

1. Venting Through A Window

By far, the most common way to vent your portable air conditioner is through a window. Most unit comes with a standard window kit that will fit perfectly in a traditional-sized window. To do so, just place the portable AC close to a window, attach the exhaust connector to the dedicated slot, install the window adapter securely to the window frame, fasten it, and you’re done. You can refer to the bundled instruction manual for further information.

The only downside with venting through a window is the compatibility issue. It will not fit well on some window sizes and additional conversion might be needed to make it work. Make sure the portable AC you are about to purchase fits the requirement.

Portable Air Conditioner Venting Window

2. Venting Through Casement Windows

Casement windows are slightly more complicated for portable AC ventilation than traditional windows. It is because the wide opening leaves many spaces similar to a door. The standard window kits are not compatible with the installation; however, there are ingenious ways to work around it. Most people will create a makeshift vent by removing one window pane and replacing it with particleboard, wooden panel, or Plexiglas. They will leave just enough space for the exhaust hose to fit it through so no cool air will be able to escape. Do allocate some time and effort (about half a day) if you do indeed of proceeding with this method.

3. Venting Through Sliding Doors Or Windows

Like casement, venting a portable air conditioner through a sliding door or window is doable but complicated given the lack of a proper window kit. You will need to purchase additional parts and modify the existing window bracket to ensure no cool air leaks out. A wall air conditioner might be the better option if the amount of time and money far exceeds the effort spent.

4. Venting Through A Wall

For any room without windows, e.g. garage, laundry room, vent the hot air out through a wall similar to a wall air conditioner. You will need to hack or drill a hole in a wall that can fit the exhaust duct. Once the exhaust hole is placed, seal it with silicone caulk and plug it in the portable AC when cooling is needed.

The biggest drawback with this method is the cost. It is not practical, especially if you are staying at a rented place where it is impossible to renovate. Consider the other venting method below, or opt for an air purifier fan that cools and cleans simultaneously.

5. Venting Through A Drop-Ceiling

Another popular, non-window, portable AC venting option is through a drop-ceiling that connects the hose upwards. Through reconfiguration, it is ideal for the basement, attic, bathroom, server room that lacks windows, and a connecting room to exhaust the hot air. Given most ceiling tiles are lightweight and easily removable, you can easily cut a hole to adapt the exhaust hose without the need for cement or sealant. Still, if budget permits, consider upgrading to a more permanent solution i.e. ceiling air conditioner that offers a similar outcome with better cooling BTU ratings.

6. Venting Through A Floor

Uncommon but possible. You can also vent a portable air conditioner through a floor similar to a ceiling. The only issue with a floor is the concrete base requires significantly more effort to install an exhaust hose. Unless there is a pre-existing hole, we recommend moving up than going down.

7. Through A Dryer Vent

A controversial method of releasing hot air that manufacturers do not recommend due to safety reasons. You can connect the portable air conditioners to an existing duct e.g. dryer vents. Installation can be tricky as most dryer vents have a smaller dimension than portable air conditioner exhaust hoses. You will need to modify the connecting port with a cap or tape and anticipate some reduction in cooling efficiency. Make sure the hose is securely connected to prevent any injury risk.

Venting Through A Window

Is There A Portable AC That Does Not Need To Be Vented?

Evaporative coolers are ventless portable air conditioner that does not need to be vented. It uses evaporation technology that supplies cool air by releasing moisture. As such, it is effective in a drier environment but ineffective in humid areas.

Do All Portable Air Conditioners Have To Be Vented Out A Window?

As long as you can collect and transfer the heat outside, a window is not necessary to vent the air with a portable AC with a self-heat pump.

Can You Vent A Portable AC Into Another Room?

Yes, you can, but it is not the best option. The adjacent room would have to deal with a higher temperature due to increased heat conduction.

What Other Ways Of Venting A Portable AC?

Most portable air conditioners are designed to vent out the hot air through a window, as indicated by the bundled kit. However, you can get creative by venting through the floor, chimney, room to room via doors, or exhaust fan. The sky is the limit.

Can Portable AC Vent Through A Screen?

It is possible to vent a portable air conditioner through a screen. Still, there will be some resistance to the airflow depending on the screen's material, thickness, and structure.

How Long Can The Exhaust Hose Be On A Portable Air Conditioner?

Depending on how powerful the portable AC is, the exhaust hose's length can stretch approximately 48 inches with minimal impact on its performance. The shorter the hose, the less chance it bending and affecting its cooling efficiency.

Final Thoughts

As shown, portable air conditioners work best in a room with windows. However, it will also work in a windowless room through various venting options. Some models e.g. evaporative coolers also do not require any venting but at the cost of the cooling efficiency. Ultimately, choose the venting option that best suits your home. We hope this guide will clear any doubts you have left about portable air conditioners.

Max Fernandez

A loving father and a dedicated reviewer for airfuji.com with more than 1000 air purifiers under his belt. Max Fernandez is also one of the million patients currently suffering from asthma. Feel free to nudge him if you have any questions.