The LLumar Window Film Blog
Using the Sun for More than Solar Power
When it comes to making the most of the sun’s benefits for your commercial building, solar power often comes to mind. Solar photovoltaic panels are becoming more common (in fact, installed U.S. solar energy capacity grew by 418% from 2010 to 2014, according to CleanTechnica).
But commercial facilities can take advantage of sunlight in other ways, too, by essentially bringing it indoors. Daylight can help reduce a building’s reliance on electric lighting (reducing as much as one-third of total building energy costs, according to the National Institute of Building Sciences’ Whole Building Design Guide). When daylight is introduced to spaces during wintertime, it can also help maintain comfortable temperatures and decrease HVAC energy usage.
But the big question is often: “How can we do this without the side effects that sunlight can bring with it (glare, uncomfortable solar heat gain, etc.)?”
Preventing glare is important if you plan to use daylight to help warm colder spaces or provide natural light. If the sun’s rays aren’t controlled as they enter the building, tenants and occupants may be bothered by direct or reflected sunlight. Window shades can block or redirect sunlight, but in doing so, they may prevent daylight from penetrating the interior. The benefits of natural lighting (such as reduced energy costs, increased tenant satisfaction levels, and even improved productivity) may fade if shades and blinds are the method of choice for controlling excessive brightness.
High-performance, low-e window film, however, can prevent distracting glare while still letting in natural light. It blocks up to 99.9% of harmful UV rays, allowing for controlled natural daylight and potentially reduced artificial lighting requirements.
Preventing uncomfortable solar heat gain is another important factor when considering the incorporation of daylight into your building. Unprotected windows will allow natural light into the space, but also warmer temperatures that come along with the sun’s rays. This can cause tenants and occupants to want to move away from windows, close blinds/shades, or operate fans. Window film can help with this by reducing solar near-infrared heat while still allowing visible light to pass through.
But many window films have a big drawback: they may reduce solar heat gain from windows all year long. In colder climates where solar heat gain is desired during the heating season, traditional commercial window film can end up increasing the amount of heat required from an HVAC system. High-performance, low-e window film, however, may improve HVAC energy efficiency by decreasing thermal heat loss through windows and keeping spaces warmer.
How have you successfully incorporated daylight into your building to improve comfort levels and save energy?