Window Coverings That Help Reduce Heat Loss or Heat Gain

Why windows are important:

Windows play a crucial role in determining the environment within a living space as they help mobilize heat. The principles of physics teach us that heat moves from warm areas to colder ones. This means that a window will allow heat to enter on a warmer day and escape on a cold day or night. This, however, is the opposite effect of what most people desire in the given circumstances. Transfer of heat occurs in three forms: radiation, conduction, and convection. Sunlight is a form of radiation and it passes through the window. The glass of the window is a conductor for the heat transfer and convection occurs if warm air moves towards cold air through gaps or cracks in the window.

How window shades help save energy:

Ensuring that your window has ample amount of shade or a protective coating can help prevent unwanted heat loss and thus, save energy. According to the United States Department of Energy, proper window treatments such as cellular shades can help to reduce energy costs by up to 20%.

The effectiveness of a window treatment is measured by its Shading Coefficient. The Shading Coefficient is a value that measures the ability of the window treatment to reduce the amount of solar heat gain. Ideally, one should select a treatment that has a lower shading coefficient as it ensures less heat gain by radiation.

Types of window shading available:

There are different types of window coverings that are available. Each may have a different aesthetic feel and offers different levels of protection from energy loss. Window quilts are considered to be one of the most efficient forms of window treatment to prevent energy loss. Other solutions include the use of wood or bamboo blinds, window blinds, and mini blinds. It has been found that honeycomb cell shades and wood faux or wood blinds are more effective than aluminum blinds or roller shades. These, however, offer a limited amount of insulation for the window.

How to ensure window shades are effective:

In order to be effective, the side of the blinds that face the window should be of a reflective color like white. Ideally, one should opt for blinds with trapezoid bottom rails because these blinds close with lesser gaps and therefore, block light more effectively. Closing blinds with the leading edge up also helps reduce heat loss.

Alternate solutions for windows:

An alternate window solution is to apply a reflective film. This film is applied on the interior side of the glass to reflect heat back. These films should be ideally used on windows that receive direct sunlight and lie on the East or West face of the house. Today, low emissivity coatings are also available. This is an invisible coating that helps to reflect heat and reduce the amount of ultraviolet light entering the window. Another innovative invention is the solar shade screen which is made of fiberglass and has a special weave that blocks up to 70% of direct sunlight.