Personally, I feel that conduction and convection are methods in which heat flows. Conduction utilizes a solid to conduct heat while convective heat flow reacts to fluid dynamics and the differential buoyancy which causes hot air to rise and vice versa. Radiation in my opinion, is not a method of heat flow but a source of energy in an electromagnectic wavelength, much like light. Conduction is fairly easy to limit by placing a non conductive or low mass separation in its path. This creates a constant movement of heat as long as there is a temperature differential between the air or liquid and the source of heat.
Fibrous insulation works well to limit convection.
When radiant heat is viewed as a form of energy, a wave length, rather than a type of heat movement, it becomes easier to understand how it behaves with fibrous insulation products. Therefore, if you can reduce the amount radiant energy, you reduce convective and conductive heat loads which increases comfort and significantly reduces the need for energy. Radiant heat can only be absorbed or reflected. The amount of which is determined by the surface it is striking, angle to the source and absorbtivity of the surface. Radiant heat strikes the earth, our homes, our cars, etc., which in turn heats the air.