How To Insulate Windows To Keep Heat Out and cool air in

How To Insulate Windows To Keep Heat Out During Summer

Ian Mutuli
Updated on
Ian Mutuli

Ian Mutuli

Founder and Managing Editor of Archute. He is also a graduate architect from The University of Nairobi, Kenya.
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Are you wondering how to insulate windows to keep heat out? Well, you are in the right place. The amazing news is that you can create a sturdier barrier between the outdoor and indoor environments to make your home atmosphere comfortable during the summer or winter. That said, there are many ways to insulate windows, and the methods range from simple to complicated, low-tech to high-tech, and nearly free to relatively expensive.

You can easily insulate your windows to keep Summer heat out using some of these methods: Weatherstrip Your Windows, Install Cellular Shades, Install Insulating Shutters, Apply Bubble Wrap, Add Reflective Window Film, Use thermal curtains, and Invest in Energy Efficient Windows. With that in mind, let's dive in and learn more about insulting windows.

What are the Benefits of Insulating Windows?

Insulated glass windows are an excellent way to keep your home at a comfortable temperature without having your curtains closed. These windows usually use two panes of glass instead of one, creating a pocket of air within the frame of the window. Insulated windows will still let sunlight through but better keep out the heat and cold. 

Windows can be a relatively costly home feature, accounting for solar heat gain during the summers and substantial heat loss during winter. Effective window insulation limits heat loss and also helps regulate the temperature of the interior glass. They are also incredibly effective since they increase energy efficiency in your home.

In addition to being a good heat insulator, well-insulated windows will make a great noise insulator. Again they provide greater security since they are hard to break since they have two panes of glass. They will also improve your energy costs since they will provide better heat control. Furthermore, the insulating windows will increase the value of your home.

Having stated the benefits of insulating windows, let's now look at how to insulate windows for the summer heat.

How to insulate windows for summer

If you are looking to fix drafty windows for your home, you should earnestly consider getting energy-efficient windows. These windows can deliver everything from greater temperature control to enhanced home security. Here is how you can do it by yourself.

1. Preparations Windows for Insulating

It's reasonable to begin by analyzing the situation. Rather than giving your home an entire energy inspection, identify the critical areas for heat gain or loss. Next, assess where the heat gain or heat loss. Again give some attention to the type of windows you are thinking of insulating. Finally, before selecting the insulation method from the available options, you should again consider your objectives.

Temperature regulation is our main objective here, but you also must think about how much to increase the insulation value and what tradeoffs you are ready to make. With that said, it is necessary to factor in cost. For instance, using high-tech insulation methods will mean you will have to dig more into your pocket.

When you have made these considerations, you will now need to carefully take the measurements of the casing, windowpanes and window frames. If you decide to mount blinds or shades, you need to know if you will insulate inside or outside the casing. However, it is necessary to note tha having them inside will increase their effectiveness.

2. Treating Your Windows­

Installing curtains, shades, and valences can go a long way toward limiting or allowing airflow around a window. Nonetheless, most people's window treatments in their homes do not deliver optimal insulation since they are normally installed with aesthetic instead of functional considerations in mind. ­

3. Steps and Tools Used for Insulating Windows

Since you can use different methods to insulate windows, not all DIY projects for insulation will follow the same methodology. We have provided a few basic procedures you will need to know regardless of your method. Again we will look at some of the tools you might need when insulating your windows for summer.

1. Plastic films

Finding window installation kits at home repair stores or hardware is easy. In most cases, the window installation kit will have window films and double-sided adhesive tape. A high reflectivity window film will help block against solar heat gain and safeguard against glare and ultraviolet exposure. The UV reflective window film will also allow light while blocking harmful UV rays.

installingt window films

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You will need to adhere the double-sided tape around your window frame on all sides, then install the window film on the tape so it covers your window. Then cut a little hole while installing the film and creep the control rod through so the blinds can easily be closed and opened. The other tool needed to get the job done is a hair dryer. You will blow hot air at the window films, tightening them and making a tight seal with no wrinkles.

2. Insulating drapes

Drapes usually have a heavy material but still provide a tight seal. Using drapes will limit your room air from circulating into the space behind your curtains. You could use velcro, snaps, staple or weights to ensure that no space is left between the window frames and the drapes or between the floor and the windowsill.

3. Insulating window sashes

Insulating window sashes

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Since the primary source of heat loss is not via the glass but through the apertures in the window frame and the sashes rattle. You could easily use a hammer and a pry bar to extract molding from around the window. Then cut a stripe of foil-faced rigid foam insulation to fit into the space between the side jamb and drywall. When that is done, drizzle some maximum-expanding polyurethane foam adhesive into the space at the bottom and top of the window.

4. Weatherstrip

The weatherstrip is easy to go to, a method that will work for both winter and summer days. During summer, you will be able to keep hot air out and cool air in and in the winter, you wil also be able to keep warm air in and cold out.

The benefit of using this method is that you will not end up with a dent in your energy bill. Another great bit about this method is that there are various weatherstripping types. So you can shop around and find the insulation material that maximizes effectiveness and fits your budget.

You will first clean the channels through which sashes move in the installation window. Using a knife, chip off any present paint. Then you will need to measure and trim the weather stripping to fit the channels precisely. Nail or stick the weatherstripping in the channels, and you are good to go.

5. Bubble wrap

Bubble wrap

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Bubble wrap is another great way to insulate a window if a warmer home is an urgent requirement. To use this method, you will only require to mist the clean panes of glass with water. Then position the bubble side of the wrap against the mist windows. You could use the adhesive tape found in a window film kit.

6. Cellular shades

Cell shades are perfect if you want a more attractive method to insulate windows for summer. They are ideal since they have built-in pockets that will help keep cool air in and hot air out. This limits any excessive or sudden changes in your room’s temperature, which means the method is perfect for both summer and winter.

7. Install removable magnetic window insulation

Magnetic window insulation is an excellent solution if you enjoy occasionally opening your windows during the summer or winter. Rather than using tape or magnets to hold the insulating vinyl, you can place the insulation in place only on hot days.

8. Blackout blinds

If it's too hot and you don't want the sun's heat anymore, using the blackout blinds will be a great option to insulate windows. The blinds will block light from getting to your room ad will ideally keep the room dark.

9. Caulk

For those looking for relatively cheaper options, using caulk would work best. Unfortunately, all caulk occasionally requires reapplied, especially if your window area is bound to expand or contract. The best bit about Caulk is that there are three types of caulk for different surfaces.


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Usually, Silicone-based caulk is most suitable for metal and glass surfaces but is not paintable. Paint-quality caulk is utilized for areas you intend to paint, and the water-based latex caulk is used to seal cracks in the window sash or around the window.

10. Insulating Curtains

Using insulating curtains at the window is another great method to help with insulation. Although this is a method you usually need to use after installing caulking or weatherstripping, it is highly effective.

Additionally, this method is the simplest and one of the most effective ways to insulate especially using thermal curtains. The curtains will not only add a touch of class to your space, but they are incredibly effective at blocking light from outside. Again they are sufficient at controlling cold air from entering your home.


Insulating your windows is an inexpensive way to improve energy efficiency in your home. It is an easy-to-do project that anyone with basic skills can do within a few hours. The amazing bit is that you could easily get insulating kits or curtains from your local home repair stores or hardware. Additionally, most of the methods are have mentioned in this article can be used during the summer and the winter.

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Ian Mutuli

About the author

Ian Mutuli

Founder and Managing Editor of Archute. He is also a graduate architect from The University of Nairobi, Kenya.
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