Liquid crystal (LC) or polymer-dispersed liquid crystal (PDLC) devices are called “privacy” glass as they turn from a transparent state to an opaque state, which has a milky white hue. LC devices are fabricated in a double laminated configuration with the LC inside two plastic plies encased in two glass sheets. They are used in interior glazing applications where privacy is required. They are not recommended for envelope applications because they do not control heat gain and because of the degradation potential of the organic LC material and the double glass/plastic laminate construction in exterior environments.
Suspended particle devices can be varied from a high transmission state to a lower transmission, tinted state, like electrochromics can. Applications include fast switching displays and interior dynamic mirrors. The material is organic based and fabrication method is similar to LCD. Therefore, durability concerns prevent it being recommended for the building envelope. Also, the light modulation and energy saving performance is only moderate compared to electrochromic products. It requires 50-100V alternating current to power, and the “off” state is tinted.