Life hack for sun protection: how to stick foil on a window and save on air conditioning

Those who happen to live in an apartment where the windows face south, east or southeast know firsthand what hellish heat is, because from early morning until two or three o’clock in the afternoon, it is possible to protect yourself from the sun’s rays only with the help of tightly drawn blackout curtains. However, there is another, less well-known method - sticking foil on the windows to block the sun. Together with a hardware store salesperson and an interior designer, we figured out which foil is suitable for this purpose, how to attach it to the glass, and whether it needs to be removed in advance of winter.

Choosing solar foil

When you hear the word “foil,” you most likely imagine thin, flexible, paper-like metal sheets for roasting vegetables or meat. And for good reason, because this kitchen attribute is often used as a shield from scorching rays, gluing it to window glass.

But there is a more modern option for sun protection - a special foil (mirror) film for windows.

A table in which we have collected all the advantages and disadvantages of both types of foil will help you make your choice.

	Food foil	Foil film
Light transmittance	Absolutely does not transmit light. If you cover the entire window with it, the room will be completely dark. For this reason, as a rule, foil is applied only to the lower ⅔ of the glass. This has its drawback - through the unprotected part of the window, rays penetrate into the room, heating the floor and walls.	There are foil films with varying degrees of shading - from 5 to 70. For residential premises, values from 20 to 35 would be ideal, but, focusing on personal feelings and needs, you can choose any available option.
Application to glass	To glue the foil to the window, you will need an adhesive compound.	An adhesive layer has already been applied to one side of the foil film.
UV protection	Reflects 100% of UV rays, but it is worth remembering that ultraviolet radiation will enter the room through unsealed areas of glass.	Depending on the brand and manufacturer, it blocks up to 99% of UV radiation.
Price	At the time of writing, one roll (length of the panel - 10 m, width - 29 cm) was sold at Fix Price for 77 rubles.	Sunscreen mirror film measuring 0.6x3 m will cost 40 rubles in the OBI hypermarket.

Window sticking: rules and nuances

Self-adhesive mirror film is easy to apply:

Use a sharp utility knife or scissors to cut a piece of film. Its length should be equal to the height of the glass.
Remove a small piece of protective paper from the film and carefully apply it with a sticky layer to the top of the glass (the glass should be perfectly clean). Smooth with a damp cloth to remove wrinkles and air bubbles.
Continue to gradually remove the film from the protective paper and glue it onto the glass, carefully smoothing it out.

As for food foil, the easiest way to stick it is with double-sided tape. Another option is also possible: spray the glass with soapy water from a spray bottle and attach foil to it. If the width of the roll is smaller than the width of the glass, place the panels overlapping.

Please note: you need to glue the foil onto the window with the shiny (reflective) side facing the street.

Questions and answers

How to remove foil from glass?
If you have a mirror film attached, simply hook the edge with your fingernail and carefully remove it from the window. Food foil that has been “set” on soapy water also easily comes off the glass. If double-sided tape was used as glue, traces of it can be removed by wiping the glass with medical alcohol or acetone.

Does foil help protect furniture and wallpaper from fading?

Yes, because it does not transmit ultraviolet radiation.

Do I need to remove the film for the winter?

No. Mirror film can last 2-3 seasons or even more, regular foil - 1-2 seasons.

Does this method of sun protection have additional advantages?

Self-adhesive film will protect you from splinters if the glass breaks for any reason. Ordinary foil does not have this property - it will simply tear.

On sale there is a regular, non-self-adhesive, sun protection film with a mirror effect. Is it worth buying?

Not worth it. It is attached to the glass using soapy water, but, unlike food foil, it sticks tightly. It is almost impossible to remove it, and attempts to use a knife only lead to scratches on the windows.

Now you know exactly how to cover windows with foil to protect from too much sun. This method will help you reduce the temperature in the room by 5–7 °C and save on installing an air conditioner.