Lijan Roof Cool Insulation's can drastically reduce overhead costs in almost any type of business and reduce A/C heat load and run time. Lijan Roof Cool Insulation's should be considered in all building designs as well as renovations and up-grades to existing buildings. aluminium foil which reflect the heat and reduce the heat inside a room . The heat or air temperature is blocked and reduce the air temperature inside a room which it act as a shield.