Insulating window covering to save energy.
As the summer is approaching, and most folks consider energy savings much like they pondered it with the onset of winter, one faces the conundrum of deciding whether to use shades, shutters, blinds or drapes. Especially those just venturing out towards independence, or those new homeowners. And in today’s world of seesawing weather, it would pay to be sensible about window shading. After all, we do want to leave a stable environment for the next generation, don’t we?
That window shading reduces the consumption of energy in homes and offices is an undisputed fact, and are a lot cheaper than changing windows with every upgrade that hits the market, no matter how efficient they are. And the bonus is that window shading adds to the aesthetics of a home, so it seems important to evaluate the needs of each room individually before arriving at a decision. Most people I know would set off to buy drapery for their windows – they love the layered effect it offers when sheers and heavy drapes are combined. One friend said, ‘Oh, I want the same effect I saw the drapes provided when I stayed at the Radisson’, without considering the fact that the Radisson pays out heavily in terms of utility bills! Or the White house – no expense is spared in outfitting the White house with state-of–the-art energy efficient, bullet-proof windows, so the White house decorators don’t have to think twice in considering energy efficiency vs. power glam!
So what’s it to be? Drapes, Shades, Blinds or Shutters?
Caulking and Weather Stripping.
Air infiltration or leakage cannot be stopped by window covers – this issue needs to be addressed first – windows need to be caulked, and weather-stripped to prevent air seepage. Once that is done, consider window covers that will block heat gain in summer and prevent heat loss in winter.
Window Orientation and Shading.
Once air seepage is taken care of, consider a window’s orientation before deciding on the type of shading to be used in a room. From the diagram given, it is easy to see that in summer, South and North facing windows hardly need any shading – for the form
er, adequate sun shades innate in the building’s structure would provide enough cover, and in the latter instance, light interior window shading would do the trick as north facing windows only receive the early morning and the late evening sun.
The greatest considerations need to be given to the east and west facing windows – these windows can receive massive amounts of solar gain and glare if not covered effectively, especially in those homes sporting curtain-wall window constructions!
*The above diagram is courtesy of the Florida Solar Energy Center.
There are indoor and outdoor window shading options to consider. Scientists advocate that for best energy savings, it’s best to block the sun before it reaches a window. Solutions are many, from awnings to Sarasota shutters to porches & Trellises with creepers.
Exterior window shades catch the sun and reflect some of it away from the window, some of which are transparent, so some of the radiation falling on them passes through to the window. The rest of the heat energy is absorbed by the shade material, and is mostly carried away from the window by radiation and airborne convection currents. The best examples of these transparent exterior shades are Solar Shades from Graber, made of specially designed heat and light blocking Phifer solar shading fabric. They can be manually or automatically operated to alter the amount of shading they provide.
The most effective of these solutions are those that have brightly reflecting sides towards the outside.
These conventional window coverings can be efficient in use if they hung close to windows and while drawn closed when the sun is going on its rampage, allowed to pool onto the floor or window sills. Studies have shown that medium colored draperies lined with white plastic backing reduce heat gain by 33%. Draperies also tend to remain cooler than some other options as their pleats and folds lose heat by convection.
When shades are installed very close to windows, with the sides held as close to the wall as possible to establish a sealed space, they provide some of the simplest and most energy efficient window treatments. Keep them lowered over sunlit windows during the day. These shades also come in dual roller shades, with a reflective shade and heat absorbing shade in combination, so it can be used so that the reflective surface faces the window in summer. Cellular shades with reflective outer surfaces also provide high dividends in energy saving, especially as they are available in light filtering, room darkening, and blackout versions. The blackout cellular shades provide the best room darkening and insulation, both sound and temperature, so they are the best options for bedrooms and a/v rooms.
Blinds and Shutters.
Both blinds and shutters provide protection from solar gain. Wood and Composites are poor conductors and offer wonderful insulation, added to which their operable vanes allows for impressive light, and, therefore, heat control. This is a feature that cannot be ignored as they provide a fabulous view, insulation and privacy without having to be raised, unlike shades. They can be used in practically any room, especially as they also come without route holes.
Lastly, all window coverings are available in motorized options that provide safety, ease of use and are recommended for energy savings as they can be programmed to function according to the sun’s movement in the sky.