The sheet is made with pure aluminum foil on both the sides with an air bubble sheet in between. There are three ways in which heat goes from warm spaces to cold spaces: Conduction is direct heat flow through a solid object such as a wall or a ceiling. Convection is heat movement through the air, occurring when air is warmed. The warm expands, becoming less dense and rising. Radiation is the movement of heat rays across air spaces from one warm object to a cooler object. The heat we feel from a wood stove or a quartz space heater is a radiant heat. All objects and bodies give off radiant heat. Insular- E is an effective solution for protection against radiant heat transfer and helps maintain the ambient temperature inside the shed. It is unlike other insulation product that slows down or only resists heat. Insular-E reflects heat. Regular insulation won't stop radiant heat loss. Radiant heat must be reflected with a radiant barrier.