Chemical Dynamics, LLC has successfully developed coatings that offer the coated surface an ε much lower that 0.9, thus reducing heating bills. In recognition of the energy savings properties of this coating, the Department of Energy Building in Washington D.C. utilized this technology to coat their aluminum window frames.
Coatings by nature have a high emissivity. Emissivity by definition is the relative property of a material’s surface to emit energy by radiation. It is the ratio of energy radiated by a particular material to energy radiated by a black body at the same temperature. A true black body would have an ε = 1 while any real object would have ε < 1. Emissivity is a dimensionless quantity. For example, a black or white painted (ε = ~ 0.9) aluminum object will absorb infrared energy (or heat) and be heated to a much greater temperature than a material that utilizes a coated surface that has an ε lower that 0.9.