Written by Bo Knows

Best Way To Block Heat From Windows

If you’re searching for the best way to block heat from windows, this post will help!  From a cheery awning that floats above a picture window to a simple pair of hanging drapes, windows are frequently dressed by homeowners for beauty, not function. However, using the correct materials and placement, homeowners may be able to reduce the monthly utility bill with these functional and decorative window treatments.

Types Of Heat Blocking Window Treatments

Do not simply increase the A/C when the hot months arrive, investigate ways to increase the functionality of your windows instead.  According to the U.S Department of Energy, the affects can be significant, and be easy as using medium-colored drapes that have a white plastic back that lowers the solar heat up to 33%.

Window Shades

Window shades are considered by the DOE to be the easiest and most effective approach to save energy by decorating the windows. However, correct installment is important, with shades being mounted closely as possible to the glass, adjacent to the wall creating a tight seal to minimize heat loss and gain. Meanwhile, shades that have double layer of fabric with a lighter color on the back side and darker color on the other increases functionality. Depending on the season, the shades can be turned around, allowing light color to reflect summer heat, and darker color to retain heat for colder months.

Ideal Positioning: Because shades are flexible, they are suitable for any window.

Best Use: Based on the color and material, and if they are lowered or raised, it may assist in reducing both the heat gain and loss from solar heat.

Window Blinds

Both the exterior and interior blinds are able to assist in reducing solar heat gains while the amount of desired light is maintained, along with privacy and ventilation. When lowered or closed on sunny days, blinds can reflect heat gains up to 45% (white blinds).

Ideal Positioning: West and South facing windows.

Best Use: For lowering heat gains where option for light is desired, along with privacy and ventilation.

Window Drapes

Based on the color and weight of the fabric used, drapes can assist by insulating a home from losing solar heat in the winter and blocking solar heat in the summer.

As previously mentioned, drapes of a medium color using white plastic backing can lower solar heat gains up to 33% when closed on hot sunny days. For the best results, drapes should be installed tightly to create a seal as close to the window and/or walls and possible. In addition, drapes should hang from the ceiling down to the floor.

Ideal Positioning: Due to flexibility, any orientation is fine.

Best Use: Lowering solar heat loss and gains, based on several factors.

House Awnings

Not only will awnings provide more personality to the exterior of a home, it can provide great defense against solar heat in regions with extremely hot weather. Solar heat can be reduced by awnings up to 65% in south-faced windows, while west-faced windows reduce solar heat up to 77%.

There are some features which can increase the performance of an awning. For instance, tightly woven, opaque awnings can block out the sun more efficiently compared to lose fabrics, sunlight is reflected better by light color awnings. Because hot air is trapped by awnings by the window, it is suggested by the DOE that openings are made for ventilation. With a retractable feature, awnings can allow sunlight to hit the window during winter for heat gain.

Ideal Positioning: West and South windows

Best Use: Lowering heat gained on warmer days.

Roof Overhangs

Similar operation to awnings, roof overhangs can block solar heat during the summer when properly designed, while allowing a desired heat gain during winter. When considering a roof overhang, consult an experienced passive solar designer or architect. They will be able to explain your options based on various factors, such as climate, latitude, and window size.

Ideal Positioning: South windows

Best Use: Solar heat loss and gain during new construction. Awnings are more sensible for existing windows.

High Reflectivity Film

High reflectivity film is recommended in climates that have shorter winter season, according to the DOE. The film works by reducing heat gains all year, even in winter. For a better performance, the silver film with a mirror type finish works better compared to transparent film. It is ideal for larger windows, such as large garage windows where a cooler temperature is desired.

Ideal Positioning: West and East facing windows

Best Use: Lowering solar heat gains year-round.

Mesh Window Screens

Using mesh window screens can lower heat gains as it diffuses solar radiation. It is suggested by experts that mesh screen is mounted on the exterior of the building, covering the entire window.

Ideal Positioning: West and East Facing Window

Best Use: To lower heat gains year-round.

Having exterior blinds installed can increase the effectiveness compared to interior blinds, because it allows heat to be blocked prior to it being transferred through the window and warming the room. However, exterior blinds can be challenging to install to existing windows, and best for new constructions. Integrated exterior blinds can be designed to be a beautiful façade architectural factor to the exterior of a home.

East Phoenix Shutters & Blinds

Bo Knows Shutters & Blinds proudly custom installs all types of window treatments in Mesa, Gilbert, Chandler, Tempe, and other East Phoenix Valley cities.  We will happily help you choose the very best way to block heat from your windows to keep your home cooler and save on utilities. Whether you want the luxurious plantation shutters with automatic motorization or would like affordable blinds installed, we have everything you need and a wide selection!


Leave a Reply

Your email address will not be published. Required fields are marked *