In industrial high-temperature heat pumps (HTHPs), the heat sink is the process receiving the heat, typically requiring temperatures of up to 200 °C. It serves as the counterpart to the heat source, which either delivers thermal energy or needs to be cooled.

Typical industrial heat sinks include:

• Process heat consumers – e.g. drying systems, reactors, pasteurization, or sterilization units
• Steam systems – generation of saturated steam up to 250 °C at pressures of up to 40 bar
• High-temperature hot water networks – such as district heating grids or internal heating circuits with flow temperatures above 100 °C
• Thermal oil systems – commonly used in frying, drying, or reactor heating applications
• Thermal storage systems – e.g. buffer tanks that decouple heat generation from consumption

The efficiency of a high-temperature heat pump is strongly influenced by the temperature lift  between the heat source and the heat sink. The smaller the temperature difference, the higher the system’s coefficient of performance (COP). It is therefore critical to design the heat sink to operate at the lowest possible temperature that still meets process requirements.

The selection and design of the heat sink directly affect the overall configuration of the HTHP system. They determine key requirements for the refrigerant, compressor technology, and heat exchangers. Precise coordination between heat sink and heat source is essential to ensure efficient, reliable system operation.