Cellular shades

Cellular shades are a window covering used to block or filter light and insulate windows to save energy. Cell size can vary. Cell shapes hold trapped air and create a barrier between the window surface and the a room. Since there's no test for shades they can't be ranked, but they qualified for a 2011 US energy tax credit.

Windows and doors make up for approximately one-third of a home’s total thermal loss, according to the Natural Resources Defense Council. This applies to heat loss in winter, and entry of undesired heat in summer. When air inside the room comes in contact with windows, it is cooled or warmed. By convection this air then circulates around the room. Cell shapes in the blinds hold trapped air and create a barrier between the window surface and the a room. Shades, however, provide only slight control of air infiltration.

Cellular shades can be constructed as single cell, double cell, or triple cell shades. Single cell fabric has an R-Value between 0.28 and 0.44 (1.6 and 2.5 imperial), and double cell fabric has a metric R-value between 0.49 and 0.70 (2.8 and 4.0 imperial). A 6 mm (¼”) thick single pane window has a metric R-value of 0.16 (0.91 imperial).

Unlike window blinds, which are made of hard materials, they are made of a soft paper- or cloth-like material. Typically spun lace and bonded polyester are used, but other fabrics can be used during the manufacturing process.

In common with all blinds cellular shades can reduce of solar gain in summer, and provide black out for sleeping. Also as with other window treatments, they are raised and lowered horizontally with a string. Cordless cellular shades are available to reduce the risk of strangulation for small children.

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