horizontal sliding window

Learning how to install portable air conditioner in horizontal sliding window is easy and straightforward. You can do it with novice skills, and it only takes a few minutes. Most portable air conditioners come with a sliding window installation kit for an easy fit.

Below are the steps for installing a portable air conditioner in a horizontal sliding window. We will also discuss when it is more viable to install a portable air conditioner in a horizontal sliding window rather than a window air conditioner.

How to Install Portable Air Conditioner in Horizontal Sliding Window

What You Need

  • Portable air conditioning unit
  • Window kit for installation
  • Weatherstrips or rubber seal
  • Measuring tape
  • Screwdriver


1. Choose a suitable location for the installation of your portable air conditioner

The right location offers a good balance between enough space for the portable AC, the exhaust hose, and proximity to a power outlet. Consider the height of the window to ensure that the exhaust hose can reach it without over-stretching. Also, there should be enough room for air to circulate in and out of the portable air conditioner.

2. Measure the height of the window

Slide open the window. Using a tape measure, accurately measure the window’s height from top to bottom.

3. Assemble the window panels

Usually, the bottom panel is slightly wider than the top panel. Lay both panels on the ground, one in front of the other. Slide the narrower one into the channels of the wider one. Adjust the fit so that the length of the joined window panels equals the height of the sliding window. Use the screws that come with the kit to tighten the fit of the panels.

The panels also come with weather strips. Cut the right strip dimensions for each panel and install them along the sides.

4. Install the Window Panel

Install the window panel to ensure that it fits well on the sliding window frame. Notice whether there are spaces left between the sides of the panel and the frame.

For an easy installation, hold the window panel up with the way the side at the bottom. Fit the bottom side of the panel on the lower window sill. Then, fit the upper part into the upper window sill. Gently push the window panels to the outer edge of the window frame.

If there are no spaces between the adjacent sides of the panels and the window frame, proceed with installing the exhaust hose for the air conditioning unit. If there are spaces, uninstall the panels and install rubber seals or weatherstripping on the windowsills per the dimensions of the window panel. Then mount the window panels again and confirm that there are no spaces left and there is a good window seal.

5. Install the Exhaust Hose

Take the exhaust hose and gently expand it without over-stretching. Attach one end to the back of the portable AC unit. Turn it a few times in a clockwise direction for a firm fit.

Place the portable AC unit near the window panels and fix the other end of the exhaust hose to the opening of the window panel. Most exhaust hoses have a locking mechanism on the window panel where you slide it into position until it clicks. Observe if there’s any space between the mouth of the hose and the window panel. If there is, seal it with a rubber seal or weatherstripping to ensure a good window seal around the portable AC unit.

The correct installation of the exhaust hose is such that the hose is straight. If the hose bends or folds, the heat will not flow out seamlessly.

6. Plug-in the portable air conditioner and turn it on.

Check that it is operating efficiently.

Installing a Portable Air Conditioner Instead of a Window AC Unit

how to install portable air conditioner in horizontal sliding windowIf Your Building’s HOA May Inhibits the Installation of Window Air Conditioners

Some landlords or HOAs prohibit the installation of window air conditioners on their property by tenants. In this case, a portable air conditioner is a more suitable option.

If You Have Minimal Handyman Skills

Installing a window air conditioner is a complex process that involves building a frame. It also requires advanced tools such as a table saw and takes up quite a bit of time. On the other hand, installing a portable air conditioner in a horizontal sliding window is easy and takes a few minutes, as long as you know what you are doing.

If You Want a Versatile, Temporary Air Conditioning Solution

A window AC unit is not as versatile as a portable AC unit because it can only be installed in a window. On the other hand, portable air conditioners can be easily moved from one room to another and from one place to another.

You Have Floor Space to Spare

Window air conditioners do not require any floor space. However, you need a bit of floor space for the portable air conditioner. So, if your living space is not too tight, a portable air conditioner may be suitable.

Why Is It Necessary to Vent a Portable Air Conditioner?

The basic operating mechanism of any air conditioner is that it sucks in warm air from your living space, dehumidifies and cools it, then releases it back into the room.

The hot air is absorbed by the refrigerant. The refrigerant is channeled to the condenser coil, where the heat is transferred to incoming atmospheric air, making it hot.

Every AC unit requires a mechanism to eject the hot air. If the hot air is not vented, it will inhibit the unit’s ability to cool the intake air and not provide you with the cool air you expect from your portable unit. As a result, the air conditioning unit will work harder to reach its cooling capacity, resulting in higher energy bills.  

Different types of air conditioners have different methods for venting. A portable air conditioner can be vented through a window or a sliding door.

Tips for How To Install Portable Air Conditioner in a Horizontal Sliding Window Effectively

Carefully Read the Manufacturer’s Manual Before Installing the Air Conditioner

While articles like this will provide you with general guidelines for installing your portable air conditioner, you should still read through more specific instructions for your model. For instance, the manufacturer may have specific instructions on placement location for your slider window.

Connect the Unit to the Right Power Outlet

Typically, air conditioners draw large amounts of power to operate. Each portable unit has a specific power rating and recommended power source. Make sure that you plug it into the correct power source. It is advisable to plug it into a grounded electrical outlet, or else it could overdraw the power source, causing your sockets to trip or cause a short circuit in the unit.

Also, make sure to seal drain openings and inspect the unit for water leakage regularly. If water from the portable unit comes into contact with the power source, it could cause a short circuit.

Be Cautious When Using a Portable Air Conditioner in a Household with Pets or Children

Portable air conditioner units are high-powered appliances that can pose the risk of electrocution. In a household with children or pets, they could unplug the exhaust hose from the window or the unit, unplug the power source while the unit is still powered on, or touch electrical outlets with wet hands. Never leave children or pets unattended in the same room as a running portable air conditioner.

Bottom Line

If you are looking for a versatile, temporary air conditioning solution for an individual room, a portable air conditioner is a great option. It is easy to install by yourself and requires minimal tools. You also do not need to seek permission either from your building HOA or municipal to install it.