Silver Spring, Md./September 26, 2006—Adding to NFRC's growing family of label options, Dynamic Glazing (DG) products get ready for certification.
DG products include any fenestration system that has the ability to change its performance properties. Currently, there are two types of DG systems –"switchable" glazing technologies and internal shading systems.
- Switchable glazing technologies are electrochromatic (sensitive to an electric charge) glass systems within an Insulating Glass Unit (IGU) that can change the energy performance of a door or window with the input of an electronic control signal. The control signal simply tints or un-tints the window, changing the Solar Heat Gain Coefficient (SHGC) and Visible Transmittance (VT) of a fenestration product. The U-factor for these particular systems remains constant.
- Internal shading systems consist of blinds between glazing panes that open and close, changing the SHGC and U-factor of a fenestration product.
DG products provide consumers with another option when choosing a window or door product to suit them best, whether it is at home or in the office. As a high-performance technology, these products provide a variety of benefits, including lower energy costs due to controlled daylighting and prevented unwanted heat gain or loss. Still relatively new, the technology is expected to grow substantially in the coming years.
These products will be tested and rated using the same reliable methods that NFRC currently requires, allowing for the multiple states of performance that dynamic glazing offers.
A Dynamic Label
Just as the traditional NFRC label allows consumers to compare the energy performance of a fenestration product on a fair and equal basis, so does NFRC's DG label.
The label contains additional identifiers to help consumers and code officials understand the product's contrast in energy-performance ratings. The label indicates the endpoints of the product's performance. For switchable glazing products, the label's endpoints are the full 'on' and full 'off' states. The endpoints for internal shading systems are indicated at the full 'open' and full 'closed' positions.
"Dynamic glazing products are unique in the sense that rating only one position of the product provides no useful information on the thermal benefits of the dynamic glazing," said Jessica Ferris, NFRC’s certification manager. "Providing the minimum and maximum performance level rating clearly defines the range a user can expect from the glazing, which is in line with what NFRC does when certifying any fenestration product."
Another identifier unique to the DG label is the variable arrow. Some DG products are able to tint or adjust to intermediate states, allowing for a performance level between the endpoints. The dual-directional, variable arrow will reflect the product's intermediate energy performance level.
The board-approved label is expected to arrive in the marketplace by fall of 2006. To help consumers understand this technology and how NFRC's label can help them determine its energy performance levels, an informational fact sheet is available on NFRC's Web site at www.nfrc.org/factsheets.aspx for download.
