How to Insulate Around a Window Air Conditioner: My Top Tips

As summer arrives, there’s nothing quite like the relief of feeling cool and comfortable in your home thanks to a trusty window air conditioner. However, having that air conditioner in place can also create some energy inefficiencies by letting hot air in and cool air out. That’s why I’m here to share my top tips on how to insulate around a window air conditioner, so you can enjoy a cooler home while saving money on your energy bill.

Key Takeaways

  • Proper insulation around a window air conditioner can help save energy and money on your energy bill.
  • Assess your current insulation and determine if additional insulation is needed.
  • Using an insulation kit can be a helpful DIY solution.
  • Properly insulating the window frame and glass are essential to creating an airtight seal.
  • Maintaining proper airflow is important for window air conditioner efficiency.

Assess the Current Insulation

Before insulating around your window air conditioner, it’s important to assess the current insulation to identify any areas that may need improvement. Start by inspecting the seal around the unit to check for any cracks or gaps, which can allow warm air to seep in and cool air to escape. You can use a caulk or weatherstripping to seal any cracks or gaps you find.

If you feel a draft while standing near the unit, it may also be necessary to add additional insulation to the window frame or glass. Drafty windows can significantly reduce the energy efficiency of your air conditioner and lead to higher energy bills, so it’s important to address the issue promptly.

Use an Insulation Kit

If you’re looking for an easy way to insulate around your window air conditioner, using an insulation kit is a great option. These kits typically come with foam weatherstripping and a window insulation film. Here’s how to use one:

  1. Clean the area around the air conditioner. Make sure there is no dirt or debris that could prevent the foam weatherstripping from adhering properly.
  2. Cut the foam weatherstripping to fit along the perimeter of the air conditioner unit. Press it firmly into place.
  3. Cut the window insulation film to fit the size of your window. Apply it to the window frame using double-sided tape.
  4. Use a hairdryer to shrink the film and remove any wrinkles or bubbles.

Once the kit is installed, you’ll notice a significant reduction in drafts and outside noise. Plus, the insulation will help improve the energy efficiency of your window air conditioner.

Insulate the Window Frame

One of the most important steps in insulating a window air conditioner is to properly insulate the window frame. This will help prevent drafts from entering your home and keep the cool air inside where it belongs.

To insulate the window frame, you will need to use a foam weather stripping tape. This tape can be found at most hardware stores and is easy to apply. Simply measure the length of the window frame and cut the tape to size. Make sure to clean the surface of the window frame before applying the tape, as dirt and debris can cause it to not stick properly. Once the tape is in place, press it firmly against the frame to ensure a tight seal.

If you notice any gaps between the window frame and the air conditioner, you can also use a foam sealant to fill them in. This will help prevent drafts from entering your home and improve the energy efficiency of your air conditioner.

By properly insulating the window frame, you can help improve the performance of your air conditioner and keep your home cool and comfortable all summer long.

Insulate the Window Glass

Don’t forget to insulate the window glass as well. This is especially important if you have single-pane windows. Single-pane windows let in heat during the summer and cold air during the winter, which makes your air conditioner work harder to maintain a comfortable temperature.

There are specialized window insulation kits available in most hardware stores. These kits include a plastic film that you attach to the window frame with double-sided tape. You then use a hairdryer to shrink the film, creating an airtight seal around the window.

If you don’t want to use a kit, you can also try using bubble wrap. Cut the bubble wrap to the size of the window and spray water on the window. Then, place the bubble wrap on the window with the bubbles facing the glass. The water will make the bubble wrap cling to the window, creating an insulating barrier.

Maintain Proper Airflow

Proper airflow is crucial for maintaining window air conditioner efficiency. If the unit is not getting enough airflow, it will have to work harder to cool the room, which can result in higher energy bills and a shorter lifespan of the appliance. Here are a few tips to maintain proper airflow:

  1. Keep the filter clean: A dirty filter can restrict airflow, so make sure to clean or replace it regularly.
  2. Clear the area around the unit: Make sure the area around the air conditioner is free of any obstructions, such as furniture or curtains, which can block airflow.
  3. Use an additional fan: If the room is particularly large or has poor ventilation, consider using an additional fan to help circulate the air.

By following these simple tips, you can ensure that your window air conditioner is running efficiently, which will not only save you money on your energy bill, but also extend the lifespan of the appliance.


Insulating around your window air conditioner is a simple and cost-effective way to save money on your energy bill while keeping your home comfortable. By assessing the present insulation, using an insulation kit, insulating the window frame and glass, and maintaining proper airflow, you can significantly improve your window air conditioner’s energy efficiency.

Remember, a well-insulated window air conditioner not only saves you money but also contributes to a more sustainable future. By reducing your energy usage, you are doing your part in combatting climate change.

So why not insulate your window air conditioner today?

By following the steps outlined in this guide, you can effortlessly insulate your window air conditioner, increasing your comfort and peace of mind while reducing your energy bills. Thanks for reading, and happy DIY-ing!


Q: How do I assess the current insulation around my window air conditioner?

A: To assess the current insulation, carefully inspect the area around the window air conditioner for any gaps or drafts. Look for signs of air leakage, such as cold air coming in or warm air escaping. You may also feel drafts by running your hand along the edges of the unit. If you notice any gaps or areas that need improvement, it’s time to take action.

Q: Should I use an insulation kit for my window air conditioner?

A: Yes, using an insulation kit specifically designed for window air conditioners can significantly improve its efficiency. These kits typically include weatherstripping foam, adhesive tape, and other materials to seal any gaps and prevent air leakage. DIY insulation kits are readily available and can be easily installed by following the instructions provided.

Q: How can I insulate the window frame around my air conditioner?

A: To insulate the window frame, you can use weatherstripping foam or caulk to fill any gaps or cracks. Apply the foam or caulk along the edges of the frame where the air conditioner sits, creating a tight seal. This will help prevent air leakage and improve the overall insulation of your window unit.

Q: What can I do to insulate the window glass of my air conditioner?

A: To insulate the window glass, you can use window film or thermal curtains. Window film is a thin sheet that can be applied directly to the glass, providing an additional layer of insulation. Thermal curtains, on the other hand, are specially designed to block out drafts and reduce heat transfer. Both options can help improve the insulation of your window air conditioner.

Q: How do I maintain proper airflow with my window air conditioner?

A: To maintain proper airflow, ensure that the air filter of your window air conditioner is clean and not clogged with dust or debris. Regularly clean or replace the filter as recommended by the manufacturer. Additionally, make sure that the vents and louvers of the unit are not obstructed by furniture or curtains, as this can restrict airflow and reduce its efficiency.

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