Dual-Zone Indoor Shades

Dual-Zone Indoor Shades address glare and heat gain by integrating two separate daylight control strategies into a single unit—an upper louvered blind that maximizes daylight harvesting and a lower roller shade that controls glare and reduces heat transfer. From a cost-savings standpoint, dual-zone shades are not broadly recommended for GSA. From an occupant satisfaction standpoint, however, they should be considered— increased daylight and unobstructed views have both been shown to augment occupant satisfaction and productivity. View full-size infographic. [PDF - 422 KB]

GPG Findings 010, March 2014, Electrochromic and Thermochromic Windows. Opportunity: How much energy can be saved by daylighting U.S. office buildings? 1 billion MBTU of lighting energy can be saved by taking advantage of daylight. Technology: How to chromogenic windows save energy? Reduce solar heat gain by transitioning dynamically from clear to dark. Electrochromic (EC) use switches or automated building control systems to actively tint windows via electric current. Thermochromic (TC) use adhesive coating to adjust tinting passively with window surface temperature. Measurement and Verification: How did chromogenic windows perform in M and V compared to baseline low-e windows? 9-10% energy savings. 48-50% reduction in heat gain. Preserved views. EC tinted to dark blue; TC performance sensitive to surrounding surface geometry. Captured benefit of natural daylighting. Provided less glare. Deployment: Where does M and V recommend deploying chromogenic windows? Further evaluation. GSA is undertaking further evaluation of EC Windows in high-rise curtain wall applications with lighting that adjusts in response to daylight. [PDF - 422 KB]


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