The process of transferring thermal energy from one place to another is called heat transfer or heat transport. In the case of heat transfer from one space or from a liquid, through a partition, to a second space or a second liquid, we speak of heat transmission. Partition walls are used to calculate heat exchangers, heating and cooling surfaces, and to calculate heat loss in a building, walls or windows.
This book deals exclusively with stationary heat transfer processes, i.e. constant temperature differences over time (without heating or cooling processes).