Due to the nature of market competition, LED lamps and daylighting systems are often placed opposite each other when we compare sustainable lighting options. To a degree, this makes sense, with each representing the possible savings of artificial and natural lighting, respectively. But do these solutions need to be separate? Maybe not. Because of the way these lighting methods counteract each other's shortcomings, combining them has the potential to create a more efficient lighting design overall.
What Are Their Potential Shortcomings?
Investing in the right skylights can ensure savings, however, a less high quality system will face a few major issues. The first is heat transference. Many skylights allow high amounts of heat to penetrate and escape the building envelope. They also have the risk of being susceptible to leaks. All of these contribute to elevated HVAC costs. Light quality can also be an issue, with some systems providing light inconsistently throughout the day. Most importantly, is the hours of light per day. While the best systems can provide light for 10+ hours per day, many provide as few as four, minimizing the overall benefits.
LED lamps face a similar issue where price point can drastically affect the quality of the product. The two major issues that occur are an overabundance of blue-spectrum light, and intermittent flickering. Because it is extremely difficult to replicate the quality of daylight with artificial light, these lamps often produce excess blue light. Overexposure to this can contribute to insomnia and leave employees fatigued throughout the day. The issue of intermittent flickering, created by poor quality drivers, can also directly affect health and productivity. This is because it creates repetitive eye strain, contributing to stress induced migraines.
How Can They Be Combined?
Daylighting and Night Lighting
Daylighting systems can be used to eliminate the need for electric lights during the day, but once the sun falls below the horizon, you must rely on electric lighting. It makes sense then to utilize each system separately—in day and night. There are, however, two key issues. First, both skylights and LEDs must be strategically placed within a building to maximize the light they provide. With two systems being installed around each other, it may be difficult to ensure an effective distribution of light. Secondly, if LEDs are switched on manually, there is the possibility of lost efficiency during sunrise and set.
A better solution is to directly integrate these systems with each other. This can be done by wiring daylight sensors and LED bulbs directly into the skylights, either in the dome or near the bottom of the lightwell. Wiring these sensors through the existing hole made by a skylight reduces installation costs while also circumventing the need for lights to be switched on manually. Not only is a system like this capable of powering itself via small solar panels, this eliminates the issue of spacing, allowing both light sources optimal positioning in light your space.