Retractable Screens-A View-Friendly Way to Reduce Energy Waste in Homes with Expansive Glass
When used wisely, attractive door screens may reduce HVAC loads and improve indoor air quality.
When we spoke to window makers at last year’s Design & Construction Week in Las Vegas about the latest trends, the response at first seemed surprising: More grand, folding and sliding glass doors in the back yard; more large expanses of glass.
This makes our work as advocates of sustainability harder on several levels.
For example, more glass means more vulnerability in high wind zones, and excessive heat gain indoors as temperatures rise, plus excessive heat loss at night in cold regions.
The attraction to large glazing areas may seem at odds with research showing that homebuyers care about energy efficiency. Keep in mind, however, that the housing market has shrunk and and shifted dramatically toward high end projects since the last downturn.
Fortunately, glazing technology has improved, helping mitigate many of these drawbacks. Impact glass, for example, offers some protection from wind-borne objects. Advanced, multi-layer and gas-filled assemblies can reduce heat gain or loss, approaching the R-Value (more typically measured in U-Values) of a poorly insulated structural wall: Triple-glazed doors and windows can achieve up to R-11. Of course, these windows come at a premium cost, up to about $150 sq. ft, depending on the brand.
Trifecta: Airflow, Privacy and Shade
That large investment in glass warrants a state-of-the-art screening system. Along with the obvious role of screens in keeping out insects, they also encourage more "green" behavior. Screens allow residents to take advantage of moderate weather to open up the house and reduce reliance on mechanical cooling or heating. Screens also provide additional shading and UV resistance during hot seasons, and add a measure of privacy. Homeowners can leave their folding doors wide open, yet still be able to go about their business indoors without the whole neighborhood watching.
Also, there's been a resurgence in some regions of whole-house fan systems, which are typically much less energy intense than air conditioning. In fact, one of our recent Green Home of the the Year award winners was a home in Hawaii that relied completely on this type of ventilation for cooling. Without screen systems, these types of efficient systems would be untenable.
In the, past, some homeowners have shunned screens because they permanently impact the view that they have paid so much for, but innovative systems have now addrssed that. Retractable screens such as those made by Phantom Screens (see brochure link below) disappear into the wall when not in use and preserve the integrity of the premium view.
Not all screens are created equal, however. They need to be sturdy enough not to "blow out" when the wind picks up. Screens can't slip out of the frame the first time a pet pushes against the mesh. Here again, Phantom Screens has added the necessary extra engineering. Their units include something called MeshLock, which is a system that traps the screen securely in the door frame, adding durability and increasing the lifespan of the product.
Behavior is Key
To get the most energy savings out of any screen system, of course, depends on homeowner participation. This is where lifestyle and product flexibility come into play. Windows and doors that are operable, allow homeowners to opt for natural ventilation when weather permits.
Screens are an often overlooked piece in the complex assembly that makes a modern window or door "high performance." By including innovations such as retractability, greater strength and a wider range of frame colors, screen manufacturers are responding to both the aesthetic and sustainability trends in home design.
For examples of advanced screening from Phantom Screens, download their specification sheet for MeshLock.