The use of sunlight in factories for illumination has come full circle. In the 1800s when artificial lighting was candles or whale oil lamps, daylight poured into the mills and manufacturing facilities to provide illumination for the tasks that took place on the production floor.
The drudge of the monotonous work at the time was at least bathed in natural light, when the sun shined. Edison’s light bulb brought new light to manufacturing, which was a source more reliable than the sun and meant that work could take place 24 hours a day.
The various oil crises that took place in the 1970s and 80s forced industry to find ways to produce illumination using less energy, including application of LEDs. By the 90s, the concept of daylighting was developed to bring natural illumination into the building through the strategic placement of both the building and of the fenestration on the walls such as windows and glass doors.
Going beyond windows, over the past couple of decades a number of techniques have been developed to get more out of sunlight. Among those are motorized window treatments (MWTs).
Shining Light On The Advantages
There are many studies about the positive effects of natural light. Alan Hedge, a professor at Cornell, released a study this year that found that increased sunlight in the workplace is responsible for:
- Significant health and wellness benefits. Hedge’s study found that optimized natural light led to an 84% drop in symptoms from eyestrain, headaches, and blurred vision.
- Increased alertness in employees, who reported a 10 percent drop in drowsiness.
- An up-tick in performance. The study found a 2 percent increase in productivity, not a small amount in businesses with a large number of employees.
- A more satisfying work experience for employees overall.
Natural light, naturally, is free, and optimizing it within a building can significantly reduce operating costs. The experts at the international organization of sustainability researchers The Carbon Trust, have found that up to 40 percent of a building’s electricity is for lighting.
Passive daylighting can save an average of 20 percent of the expense for artificial lighting. Add in daylight harvesting strategies and energy expenses for artificial lighting can fall from 20 to 60 percent.
In addition, compliance with stricter building codes, including ASHRAE standard 90.1-2013, which recently added significantly more stringent requirements for daylighting controls, has helped foster daylighting innovation? California has gone further with additional restrictions on artificial lighting.
Solutions For More Sun Indoors
Welcoming into and utilizing sunlight in a factory involves an array of design tactics.
- Optimizing the building footprint for daylighting, which unlike the other tactics, is only possible for new projects. The National Institute of Building Sciences recommends that the footprint maximizing south and north exposures, with a floor depth of no more than 60 ft from south to north, is viable for daylighting.
- A growing number of plants are installing windows on their walls, with the glass tinted where privacy and security is a concern. The windows are positioned to maximize sunlight capture
- The classic saw-tooth window design that goes back decades, are windows comprised of a series of ridges. The pitched surfaces are glazed and face away from the south to shield workers and machinery from direct sunlight.
- Tubular daylighting devices on building rooftops. This approach is a distributed optical system with relatively small, highly engineered apertures that redirect sunlight to the building’s interior.
- Clearstories are sections of glazing that are high on the wall and above the main story of the factory. They provide both illumination and security.
- Skylights are probably the most typically used means of natural illumination and unlike saw-tooth windows, lay flat on the roof. Advanced gasketing and flashing have eliminated many of the leakage problems, which can be distracting to workers below and destructive to the machinery on the floor.
- Daylight responsive controls for electrical lighting systems. As the sunlight level changes through the day, artificial light intensity will be adjusted to maintain the specified room lighting.
- MWT systems to control light levels that can work in concert with daylight controls.
MWT Systems Put You In Control Of Sunlight
Manually operated awnings on the outside ground level along with shades and blinds on the inside can regulate the amount of sunlight coming into a building. MWT systems allow occupants to control the sun in a way no other daylighting method does. For plants with hundreds of square feet of windows, MWTs are critical.
First some basics on MWTs. A motor within the treatment’s roll-up tube propels the shades, blinds and awnings. Motors can be battery powered, or, for larger-scale applications, they can be wired into the building’s electrical system. They even can be solar powered , thus adding to the facility’s sustainability mission. Side guides can enable
Here is how MWTs enable plants and DCs to maximize and automate sunlight and help bring about the benefits covered previously for sunlight in the manufacturing plant.
The Right Amount of Light The position of the sun in the sky is not fixed throughout the course of the day. Clouds can pass through, darkening the interior space if the window treatments are partially closed.
Adjustments have to be continually made to manual window treatment position as the sun changes, causing distractions in the workplace as someone needs to get up from their desk and make the adjustments. MWTs and artificial lights can be connected to sensors that detect when sunlight intensifies or diminishes. When low sunlight levels cause the window treatments to be totally open, interior lights can come on for the proper level of illumination.
Total Interior Comfort Control As with artificial lighting, the system controls whether to allow in additional sunshine to warm the room on cold days or reduce the amount of sunshine to minimize solar heat gain. The smart blinds system can work with the Building Automation System (BAS) to maintain the room’s set point.
When the sun becomes too hot, the MWTs can automatically close. The room can remain cooler, longer, before the air conditioning system needs to be turned on.
In addition to reducing the need for both generated lighting and room heating or cooling, some systems available can run on DC motors, saving operating energy by two thirds versus AC powered product. For facilities with hundreds of automated shade units, the savings can be significant.
Personal Preference There are an array of remote controls to manage the system, including touchless designs. Using remote controls, workers can adjust window treatment position to achieve a balance between adequate sunlight for illumination and the ability to focus on their work.
Automated and remote control also means that employees don’t have to stop what they are doing to adjust the shades. They can make changes from their workstation.
Precision Operation Manually controlled window treatments can be subject to misalignment, which often means there are cracks between the window frame and the window covering. Depending upon the time of day, this can produce an almost laser-like beam of light. In contrast, the shade hems on motorized systems can be more precisely aligned to the windows.
These systems also can detect objects in their path and can reverse operation upon contact. Furthermore, their smooth operation and soft starting and stopping prolongs component life.
Design Freedom Clearstories and skylights are high above the plant floor. Because these windows are inaccessible for manual window treatments, these building components can partially defeat the goals of daylighting and lead to heat gain. However, MWT can be used in conjunction with a skylight to manage the amount of light allowed in.
An Extra Measure of Fire Protection When a fire breaks out, the detection system will command the MWTs to roll up, enabling fire fighters to look into the building and determine who is inside.
Put The Sun To Work In Your Plant
Daylighting is an effective way to use natural light in interior spaces to increase revenues by increasing productivity and decreasing energy costs. Happier employees is a great side benefit. MWTs help maximize the benefits of sunlight and minimize the use of energy, important factors in LEED and WELL building certifications.
Though bringing in an MWT system is ideal for new construction, a building can be retrofitted to increase comfort, productivity and efficiency. Your window treatment contractor/dealer can work with your architect and plant management to provide the best solution for your facility.
Scott Blue is the Chief Operations Officer at Nice Group USA.
