V-KOOL technology is based on rejecting heat at the window versus absorbing the heat like ceramics and other film technologies.
Independent industry tests show that absorbing technologies add stress to the glass and are less efficient, therefore inferior.
When applied to glass, V-KOOL allows up to 77% of visible light to pass while eliminating over 96% of infrared and 99% of ultraviolet light.
VK40 is the solution when you are trying to reduce some glare while maximizing your heat control. VK40 will allow 43% light transmission while rejecting 65% of the heat.
VK55 was developed to meet the IEC of .40 SHGC. This product has solar properties in between V-KOOL 70 and V-KOOL 40.
VK65 offers comparable heat rejection to VK75 with slightly less light transmission.
VK70 offers the best balance between heat rejection and daylight transmission. VK70 will allow 70% of the light to transmit while rejecting 55% of the heat. It is virtually clear and will maintain the architectural integrity.
VK75 will give you the highest light transmission, but has less solar heat rejection than VK70.