This glossary includes more than 300 solar terms, as well as hundreds of additional sustainable design and construction terms.
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z AllDefinition: The emissivity of a material (usually written ε) is the ratio of energy radiated by a particular material to energy radiated by a black body at the same temperature. It is a measure of a material's ability to absorb and radiate energy.