| Windows provide light, visibility and ventilation, but they are often the weakest element in a building’s envelope from the standpoint energy, as well as security, fire, and severe weather. High-tech windows have a number of advantages, but are not in widespread use, primarily because of cost and consumer skepticism about performance. Further, even if better windows become available at reasonable costs, they will have shortcomings that well-designed moveable insulation of the kind under development by Synergistic Building Technologies can overcome much more effectively.
Shutters have been used for many centuries all over the world and they aid in the beauty and functionality window systems. The photos show some typical examples of shutters in France. Although these examples of shutters are charming and provide privacy and shade, they must be operated by hand—and they provide very little insulating value.
By their nature, windows can not have the properties of both high solar heat coefficients (SHGCs) that are useful for wintertime passive solar heating and low SHGCs that limit unwanted passive solar gain in the summer. In the northern hemisphere, overhangs are helpful in lessening the effects of summertime solar heating problems on south-facing facades, but not on the east and west. Yet summertime solar gains through west-facing (and even north-facing) glazing in climate zones that require space cooling contribute importantly to peak electricity demands, particularly on hot summer afternoons. They thus fuel the need for new power plants in such places as the fast-growing south and southwest US, even when windows in new homes meet current energy code requirements of SHGCs of 0.4 or less. Download Fenestration Report.
Windows with high R values (low U values) are less effective than those with higher U values in climates that have high diurnal temperature swings in the summer, since nighttime cooling in this case will be less effective when nighttime outdoor air temperatures are lower than indoor temperatures.
Optimally, U values and SHGCs of fenestration systems should be variable, allowing adjustment of performance to instantaneous weather circumstances, thereby achieving increased comfort and energy savings. That’s what our shutter systems achieve—and they do it cost effectively. Click here for a discussion of windows and shutters, including details of energy use in Denver's climate, from the Spring 2007 Boulder Green Building Journal.
The photo below shows one type of shutter design we are developing on the windows of a 300 year old European home.
One of the major shortcomings of external shutters has been the method for operating them. Traditionally, either the window must be opened or a complex mechanical system involving cranks must be employed. Our shutters are designed to operate wirelessly with no penetration of the building’s envelope for controls or power supply. They include self-contained mechanisms powered by small photovoltaic power supplies for opening and closing. The shutters are completely automated to optimize comfort and energy efficiency in all seasons, but may be over-ridden when desired. The shutters can provide excellent insulation on cold nights (think R = 15 fenestration systems!) and shade specific windows when needed on hot days. They can shut automatically when winds are high or fire is sensed, or be closed to ensure privacy by pushing a button on a control similar to a TV remote.
Shutters are designed to be delivered to the retrofit or new building site fully operational and ready to install. Installation is simple, quick, and can be accomplished without tradesmen. A variety of styles and custom finishes may be chosen to match the exterior of the building.
Click here to download a slide presentation about the insulating shutter systems under development at Synergistic Building Technologies. Schedule We plan to have prototypes of the first generation of exterior insulating shutters tested and in the showroom of Serious Materials (formerly Alpen Windows) , a manufacturer and marketer of high efficiency windows in Boulder, CO in the Winter of 2009-2010. These and other members of the family of moveable insulating devices will be ready for market within a year. Stay tuned!
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