An evaporation system comprises an evaporation chamber having an interior enclosed by one or more chamber walls; an evaporation source comprising (i) a source body for containing a feedstock material, and (ii) an evaporation port fluidly coupling the source body with an interior of the evaporation chamber; an insulation material; and a computer-based controller for configuring the insulation material in (i) a first configuration in which the insulation material is disposed snugly around the source body and (ii) a second configuration in which at least a portion of the insulation material is spaced away from the source body and at least a second portion of the insulation material is disposed snugly around the source body; wherein the insulation material does not cover an opening of the evaporation port in the first configuration and the second configuration.