People are drawn to the sun. Everyone wants to live, work and play in places that have plenty of natural light. Studies have shown that natural sunlight boosts productivity, memory, health and overall enjoyment-making sunlight a major factor in creating effective, usable spaces.
Glazed retractable roof enclosures maximize natural light. Imagine a building atrium that offers a warm sunlit environment in the winter-and opens up into an outdoor space in summer. An indoor pool that turns into an outdoor playground at the touch of a button. A restaurant patio where customers are bathed in natural light during the day or can enjoy a view of the stars at night.
Retractable roof enclosures offer lots of natural light-as well as fresh air, great views and versatile spaces. They can open up in nice weather or close easily when it gets cold or rainy. Commercial buildings, leisure facilities and aquatic applications can all benefit from the indoor-outdoor advantages. A retractable roof:
- offers year-round usage and great flexibility of the indoor environment
- provides up to 360 degree views of the outside surroundings
- reduces and/or eliminates the need for air conditioning and dehumidification systems
- eliminates the need for electrical lighting during the day
- contributes to maximize LEED points
- can be custom designed to meet any vision
- offers tremendous opportunities for daylighting
More Light = More Savings
Retractable enclosures don’t just illuminate their immediate area. They light up areas close by, adding to cost effectiveness and energy savings. For example, the LEED Gold Certified Salinas Aquatic Center in Salinas, Calif., incorporated a retractable roof enclosure and earned an additional LEED point due to the high percentage of space with daylighting. The glazed structure fills the pool area and the adjoining lobby and office areas with natural light, saving electricity and providing appealing sunlit spaces.
Thermal Comfort, All Year Long
One of the biggest challenges with daylighting is maintaining comfortable temperatures. Heat loss through windows can be a problem in the winter, and in summer, the sun can raise temperatures to uncomfortably high levels. A retractable roof enclosure addresses these challenges: when it’s warm out, roof panels and side walls open so heat can escape and fresh outdoor air can flow through. In cooler seasons, sunlight warms the area naturally, and the sealed enclosure keeps heat in.
Design with Daylighting in Mind
There are a number of key elements to consider when designing a space with a retractable roof enclosure.
1. Materials. Choosing glass or polycarbonate can make a difference to the overall look, design, and performance of your structure.
- Polycarbonate costs less than glass and is quicker to install. It is also very lightweight, which allows for larger opening panels. It lets in lots of light and comes in a variety of colors; however, since it is an extruded plastic, isn’t as quite as clear as glass. Polycarbonate is ideal for large projects such as a waterparks or other aquatic enclosures with large roof areas.
- Glass is beautifully clear, and can take on tints and coatings that enhance energy performance. Low-E coatings can bounce heat towards their source; in summer, they reflect heat back to the outdoors, and in winter, they direct it back into the room. Thermal pane units can be filled with Argon gas to increase R Value. To determine the best solution, look at the amount of light coming in versus the energy cost of heating and cooling the space, and take the performance of the glass-including light transmission, shading coefficient and solar heat gain coefficient-into account.
2. The height of your structure at its peak. The taller the structure, the more light is captured in the space. Heights can range dramatically depending on the application and design requirements. For example, waterparks often require extremely high roofs or specially designed cupolas to accommodate multistory waterslides.
3. Building type.
- Freestanding-all four walls are made of glass/polycarbonate.
- Lean-to-three walls are made of glass or polycarbonate, with the fourth wall being the structure to which the enclosure is attached.
4. Roof opening. The way in which a roof opens also affects daylighting. Typically, panels open from the top and retract over the bottom fixed glazing, which results in more light in the center of the building. A lean-to application may need panels that open from the bottom up, which directs light to the base of the eave of instead of shining it on a wall. Retractable roofs can bipart from the center or telescope to each end, bathing the entire space in direct sunlight.
5. Application. The amount of daylighting you want will depend on how the building is used. A structure that makes sense for a pool won’t have the same requirements as an atrium in an office building.
6. Climate. Your needs will be different if you’re building in a warm, sunny climate than if your structure is in an area that gets severe winters or has a lot of cloudy days and rain. If the area is unusually sunny, plan to minimize solar gain. If there’s heavy snowfall, factor in snow loads. If you’re dealing with sub-zero winter temperatures, design to capture heat.
7. Sustainable construction. If one of the goals for your project is to make it environmentally friendly or LEED certified, a retractable enclosure contributes a number of credits towards daylighting in addition to a number of other LEED categories. The controls for the roof are designed such that air conditioning or any heating or dehumidification units shut off when the roof is opened. A retractable roof has tremendous potential to improve daylighting-and boost efficiency and sustainability.
Talk to an experienced firm that specializes in retractable roof enclosures. They will work closely
with you to understand your vision and maximize natural light-while helping you create a beautiful, efficient, dramatic, sunlit structure that meets occupant and user needs.
Mark Albertine is president of OpenAire Inc., Oakville, Ontario, Canada. For more information, visit
www.openaire.com.