Nano grain size tungsten trioxide is a type of transparent thermal insulation nanopowder. It is said to be transparent, mainly to describe the state it exhibits when it is applied in the form of thermal insulation film. Thanks to its own photochromic performance, this type of thermal insulation material may shield UV and near infrared rays, which are the main reasons of “hot” in hot summer. The thermal insulation nanopowder may finally be applied in the thermal insulation glass of…