Abstract

Many industrial, commercial, and institutional uses of energy result in excessive rates of waste heat rejection. Heat rejection is typically inherent in process uses; however, it may be utilized to meet other needs. Recovering and reusing rejected heat is known as waste heat recovery. Waste heat is usually recovered in the forms of steam, hot water, or hot air. The recovery medium is dependent on the quality of the waste stream, the potential use for the waste heat at the host, and the cleanliness of the waste stream. In this entry, the energy engineer is introduced to issues that should be considered in the economical and technical evaluation of waste heat recovery potential. These issues include: (1) the quality of the waste heat stream; (2) the calculation of the availability and applications of waste heat; and (3) the types of heat recovery equipment available.