Shading coefficient numbers for solar screens range from 0.50 – 0.70 for interior installations 0.14 – 0.33 for exterior installations (based on openness factor and color as discussed above). The screen industry has historically used shading coefficient rather than solar heat gain coefficient-SHGC the mathematical relationship between the two is: 0.87 X SC = SHGC). The primary thermal performance of solar screens is reducing solar heat gain, as reflected in shading coefficient (SC) numbers. Photo: Solar Screen Solutions Overall Thermal Performance Darker colors generally provide the best combination of solar heat gain/glare reduction and visibility.Įxterior solar screens are often fixed panels face-mounted with clips, not that much different than an insect screen save much better solar heat gain control. For the same color of screen, the openness factor can change the shading performance by between 5 and 25% color can change the shading performance by as little as 5% or as much as 100%. Openness factors range from as high as 25% to as low as 1%, color can range from white to black. But screen color changes the portions of sunlight reflected, absorbed and transmitted color affects glare and solar heat gain reduction as well. Higher percentages of openness mean less dense weave, more total view, and less shading and solar heat gain reduction. Openness factor is simply the combined area of the screen that is open space, rather than filled with screen mesh.

The percentage of sunlight absorbed, reflected, or transmitted by a solar screen is determined by two properties-the openness factor and the color of the screen. Since screen fibers or strands are essentially round, they can refract light, increasing diffuse light entering a space. Reflective screens are more commonly used in commercial buildings. Screens with a reflective metal finish represent a relatively new approach designed to improve the performance of interior solar screens by reducing solar heat gain (reflective side facing out) in summer and reducing radiant heat loss in winter (reflective side facing in). The PVC coatings improve the durability of the screen and allow wide variation in optical properties and aesthetics, particularly with color variation. The difference in the first two is largely thickness and durability polyester screens are coated with PVC using an extrusion process resulting in thicker yarns (PVC coated fiberglass is drip coated and heat cured). Screen materials include: PVC-coated polyester, PVC-coated fiberglass, and metallicized PVC-coated fiberglass (reflective metal finish on one side). Solar screens reduce solar heat gain, UV damage, and glare while permitting significant view and light transmission. Residential solar screens are either roller shade or fixed panels, which can be installed on either the exterior or interior of a window.

This article is about both exterior and interior solar screens.