By Scott Blue
Sunlight is free. Its rays bathe the Earth with both light and heat. With the aim of taking full advantage of our nearest star, architects have started designing buildings that purposefully exploit this resource for illumination and comfort by strategically placing windows to channel these benefits to the building’s interior. With proper daylighting design, buildings can use significantly less energy from the lighting grid and HVAC systems.
Daylighting is the strategy of using this passive form of energy to illuminate and warm interior spaces. Building owners, architects, engineers, and lighting designers are perfecting technologies for maximizing sunlight. Automated smart window treatments are an excellent partner for any daylighting approach.
First, some basics on motorized window treatments. A motor within the roll up tube propels the operation of the shades and blinds. Though the motors can be battery powered, for larger-scale applications, they are wired into the building’s electrical system or even can be solar powered. Building tenants can operate the motorized window treatments using a remote control or operation can be wired into the building automation system (BAS).
Smart blinds and shades can enable building owners to fully exploit the benefits of the sun in a number of ways.
Lighting Energy Efficiency
Electric lighting uses 15 percent of all the energy generated in the U.S. The application of daylighting design can save 20 to 60 percent in costs depending on the locale’s availability of sunlight and the percentage of wall area devoted to windows. In addition, 10 to 20 percent of building cooling energy can be saved by turning off electric lights.
Of course, the position of the sun changes throughout the day or clouds can pass through and block sunlight. Motorized window treatments can be connected to sensors that detect when sunlight intensifies or diminishes, enabling the position of the shades and blinds to change as the sun changes.
Many buildings have electrical lighting systems that respond to the amount of sunlight coming into the room. Smart window treatments can coordinate interior lighting as well with the sun to provide the desired level of illumination and decrease energy usage.
HVAC Energy Efficiency
Thanks to zone interior room comfort control, different rooms will have different needs for heating/cooling based on the window configuration. This set up is crucial for energy usage as excess sunlight can consume a considerable amount of cooling energy.
As with illumination, 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 BAS to maintain the room’s set point.
In addition to reducing the need for both generated lighting and room heating/cooling, some systems available can run on DC motors, saving operating energy by two thirds. For facilities with hundreds of automated shade units, the savings can be significant.
The smart shades’ automated design knows when to open and close when room temperature is outside the bandwidth set for the area based on readings from sensors wired into the system. Remote controls enable room occupants to control the shade position and override the system if the room temperature is outside their personal comfort zone.
In the workplace, sunlight is an important element for maintaining worker morale. Studies have shown that lack of sunlight can impact the ability to concentrate, particularly during the winter. At the New York Times, workers reported positive health benefits from daylighting, augmented with automated shades.
Glare from the sunlight on computer screens is also an issue. 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 mean that employees don’t have to stop what they are doing to adjust the shades. In addition, the motors have a non-disruptive, whisper quiet operation.
Many architects design interior spaces with tall windows or windows positioned many feet above the floor. While these features may have visual impact, there are buildings with very tall south facing windows that have to employ moveable partitions to shield against heat and glare. Motorized window treatments enable architects to make these dramatic statements without the drama of dealing with discomfort and distraction. In addition, smart shades are a highly regarded amenity.
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 prolongs component life.
You Control The Sun
Three tasks are critical to a successful daylighting installation. Sunlight must be controlled at task areas during all occupied hours in terms of its affect on heating/cooling. Then there must be balanced luminance on interior surfaces. And finally, there must be sufficient ambient daylight illumination for visual tasks. An automated window treatment system maximizes the effects of all three.
Scott Blue is Vice-President Operations, Nice Group USA. Part of Italy-based Nice S.p.A., an international group in the home and building automation industry, the company offers a comprehensive range of smart, integrated automation solutions to control gates, garage doors, parking systems, wireless alarm systems, solar screens, awnings, blinds and shutters for residential, commercial, and industrial buildings.