Denver’s Reflective Insulation for Energy Efficiency What is eShield™? Reflective Foil Insulation – Thermal Protection for Roofs, Attics, & Walls Able to stop more than 97-percent of radiant heat, eShield™ multilayer reflective foil insulation is an exceptionally efficient and innovative solution to thermal insulation needs. Most types of insulation protect against conduction and convection, measured by R-values. However, they fall short of eShield™ when it comes to E-value, which measures radiant heat transfer, the main source of lost heat in homes. By coupling eShield™ with existing home insulation, you can create a complete solution to all types of heat transfer.