heatsource

A heat source is a term used in thermodynamics and engineering to describe any system, process, or object that provides thermal energy to another body or to a surrounding environment. The heat source is typically defined by the amount of heat it can deliver and the rate at which it delivers it, often denoted as the heat transfer rate, Q̇, measured in watts, and by its effective temperature relative to the receiving body.

Heat transfer from a source to a recipient can occur through conduction, convection, or radiation. The source may be in direct contact with the receiving body (as in a furnace or electric heating element), or it may supply energy remotely (as in solar radiation or a geothermal reservoir). The choice of heat source and the path of transfer are central to the design and operation of heating and energy systems.

Common heat sources include combustion (burning natural gas, oil, or biomass), electrical heating elements, solar thermal collectors, geothermal reservoirs, and nuclear or chemical processes. Passive heat sources, such as sunlight, are important in buildings and natural ecosystems. In many applications, a heat source is paired with a heat sink, and the efficiency and environmental impact of the system depend on how effectively heat is transferred and utilized.

In analysis, the heat source is treated as the origin of thermal energy input to a system, and it is contrasted with the heat sink, the recipient of that energy. Understanding the source helps in sizing equipment, optimizing energy use, and assessing emissions and safety considerations.