Viracon is one of the leading architectural glazing suppliers. The VE1-2M series was one of the first widely used products in low-e insulating glass units, with a high visible light transmittance and a shading coefficient of 0.45. Low-e coating technology continues to advance. We recommend looking carefully at a product's light-to-solar gain (LSG) factor, particularly for ASHRAE climate zones 1, 2, 3, and 4. The higher the LSG value, the more efficient the glazing unit at rejecting solar energy, while allowing the visible spectrum to pass through.
Designers should use care in selecting the appropriate color, outside reflectivity, inside reflectivity, and visible light transmittance. Do not rely solely on small glass samples to determine appropriateness for an application. The human eye is not able to distinguish differences in tint when the glass covers the entire field of vision. Viracon's color selection site can be found here: http://www.viracon.com/index.php?option=com_viracon&view=colors
Other major competitors include PPG, Guardian, and Old Castle.