A heat recovery device, also known as a heat recovery system or heat exchanger, is a technology that captures and reuses waste heat generated from various industrial processes or systems. The primary purpose of a heat recovery device is to improve energy efficiency by recovering and utilizing the thermal energy that would otherwise be wasted.

The device typically consists of heat exchange components, such as heat exchangers or heat recovery ventilators, which facilitate the transfer of heat between two fluid streams. These fluid streams can be air, water, or other process fluids. The heat recovery device allows the transfer of heat from a high-temperature stream (such as exhaust gases or hot process fluids) to a lower-temperature stream (such as incoming fresh air or water), thereby recovering the heat energy that would otherwise be lost.