What is the best heat blocker for windows?

Author: Prof. Itzel Schulist I  |  Last update: Friday, January 30, 2026

Louvered Blinds Window blinds—vertical (Venetian blinds) or horizontal slat-type (louvered-type)—are effective at reducing summer heat gain and reducing glare, while providing good daylight indoors.

What is the best thing to block out heat from windows?

Solar shades or reflective window film are the best window coverings to block heat. Solar shades confine solar heat gain and block damaging UV rays while keeping a view of the outdoors. And the reflective window films reflect heat away from the windows so they cannot enter the interior.

What is the best heat protection for windows?

Solar shades or reflective window film are the best window coverings to block heat. Solar shades confine solar heat gain and block damaging UV rays while keeping a view of the outdoors. And the reflective window films reflect heat away from the windows so they cannot enter the interior.

What is the best window covering to keep heat out?

Cellular Shades

They're one of the best window coverings to keep heat out and to keep cold out. Cellular shades come in a wide range of colors.

What window tint blocks the most heat?

Ceramic tint is one of the best options for window tinting because these are really effective, high-quality, and good-looking films. When it comes to heat and UV rejection, ceramic window tint is able to block up to 50% of solar heat and up to 99% of UV rays.

Best Home Window Films For Heat Rejection

Does ceramic tint really reject heat?

One of the most appreciated features of ceramic tint is its impressive infrared rejection capabilities. Infrared light is the primary culprit behind the heat we feel from the sun. A good ceramic tint can reject up to 90% of solar infrared light, making your drive significantly cooler.

What is best for windows to block out sun?

For insulation purposes, cellular or honeycomb shades are the most effective. The honeycomb shape helps to trap air, reducing your solar heat gain. You also may want to consider adding side tracks to your shades so they sit closer to the window and block out more heat. Also, keep in mind the colour you choose.

How can I reduce heat gain through my windows?

Large west, east and north-facing windows should be shaded for increased energy efficiency. External shading is much more effective at keeping your home cool than internal blinds or curtains, as it stops the heat reaching the glass, but using both external and internal window coverings will provide maximum protection.

What color blinds block the most heat?

What colour blinds keep the heat out most effectively in summer? White or another light-coloured blind is the lining shade you want in order to insulate against the sun in summer, and to lower the extent to which the room heats up and holds onto the heat.

How to block sun from windows without curtains?

Cardboard and Aluminium Foil

Consider using cardboard and aluminium foil for a temporary and highly budget-friendly solution. Cut the cardboard to fit your window panes and cover it with aluminium foil to reflect sunlight.

Does heat blocking window film work?

To put it simply, yes. Reflective window film blocks a significant amount of heat, just like solar film.

How much does 3M window film cost?

We'll break down each of these to give you a strong idea of what you should expect to pay. In general, you can expect to spend $5-$8 per square foot. However, luxury options like the 3M Prestige window film price will likely end up at $10-$12 per square foot.

What are the disadvantages of home window tinting?

Potential Darkening of Rooms

Some window tints can make rooms considerably darker. This can defeat the purpose of those who want to maintain the brightness of their rooms while blocking UV rays. It can also impact the look and feel of the house, both from the inside and outside.

Does putting aluminum foil on windows keep the heat out?

Aluminium foil is both pliable, cheap and highly resistant to high temperatures. Spreading tin foil on any windows that receive direct sunlight can redirect the sun and heat away from your home.

Does putting plastic on windows help in summer?

Solar heat absorption: The plastic film absorbs a significant amount of the sun's heat energy that would normally be reflected away by the glass. Heat trapping: The absorbed heat is then trapped inside the plastic layer, creating a warm microclimate between the plastic and the window glass.

How effective is bubble wrap on windows?

According to the HowToGoSolar, a free online resource geared toward educating homeowners on the benefits of solar power and energy efficiency, bubble wrapped windows show insulating improvements that are 50% better on single-glazed windows, cutting utility bills almost in half.

How to block out heat from windows?

10 ways to insulate windows for summer
  1. Add weatherstripping to your windows. ...
  2. Use window films to reflect heat. ...
  3. Invest in cellular shades. ...
  4. Purchase blackout blinds. ...
  5. Use draft snakes for window insulation. ...
  6. Insulate windows using bubble wrap. ...
  7. Upgrade to energy-efficient windows. ...
  8. Install insulating shutters.

Do blinds or curtains block heat better?

Because blinds require slats to function, heat can easily escape through the slats. Whereas, curtains don't require slats so heat is easily maintained. The thicker the curtain is the more insulated they are. However, in summer, blinds are better than curtains for energy efficiency.

What are the best blinds to block out heat?

These are most commonly available as roman or roller blinds, prepared with an innovative heat-regulating fabric, and honeycomb blinds. Blockout blinds are effective for keeping heat in or out. During winter, simply leave blinds up in the daylight hours and close them at sunset.

Why do my windows let in so much heat?

They can either contribute to energy loss or help conserve energy, depending on their design and construction. The amount of heat a window lets in is influenced by several factors, including the type of glass, the number of panes, and the direction the window faces.

Does closing blinds keep heat out?

Smart Home Cooling Tips. Close your blinds and curtains. Keeping your blinds closed during the day will reflect a surprising amount of heat radiating in through windows, especially during the time of day when the sun's rays shine directly on your home.

How to keep window glass cool?

Summer Window Tips to Stay Cool and Save Money
  1. Seal Up Any Drafts. First, check for drafts along the edges of all windows. ...
  2. Curtains. Keeping curtains or blinds up can help provide a bit of insulation. ...
  3. DIY Window Insulation. ...
  4. Reflect The Sun. ...
  5. Upgrade To Energy Efficient Windows. ...
  6. Close The Shutters. ...
  7. Create Shade.

What is the best heat blocking window covering?

Insulated cellular shades are typically considered to have the highest R-values of all window coverings. The air pockets in the honeycomb cross-sections act as insulators, increasing the R-value and reducing the conduction of heat through the window.

Does thermal film on windows work?

Insulation Window Film Significantly Reduces Heat Loss Through Your Windows. These are thermal camera images from outside the property. The outer pane of the untreated window is about 4 degrees warmer because significantly more heat is escaping through the glazing when it could be keeping you cosy and warm.

Does closing curtains keep heat out?

Close curtains and blinds

Something like 30% of unwanted heat comes in your windows so keeping curtains and blinds closed will help, especially during peak sunlight hours and on windows that face the sun. Some roller blinds are designed to let you see out while still blocking those rays.

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