National Contact Point for Renewable Energy Sources

Heat Pumps (Small-Scale)

Small-scale heat pumps are heating devices with capacities ranging from a few to several dozen kilowatts, which can be used for heating homes, offices, and industrial facilities. Their operation is based on energy obtained from an external source, referred to as the lower energy source. The first step in obtaining energy from a heat pump is to draw it from the lower energy source, which may be air or ground. Energy is transferred from the lower source when the working fluid, a mixture of liquid and gas, enters the evaporator, where it evaporates. Next, the working fluid is drawn in as vapor into the compressor, where its temperature and pressure increase as a result of compression. Subsequently, it flows (in gaseous form) into the condenser and transfers energy to the upper source, i.e., the heating system responsible for distributing heat throughout the building. At this stage, the working fluid condenses. The final component closing the heat pump cycle is the expansion valve, which reduces the pressure and temperature of the working fluid.

It is important to note that the direction of the heat pump cycle can be reversed, allowing the same device to be used for both heating and cooling. During heating, the lower source is located outside the building (heat from air or ground), whereas during cooling, the cycle is reversed: the building itself becomes the heat source, while air or ground absorbs the heat from the building.

Heat pumps have become very popular in recent years. It is estimated that in 2021, sales of these devices in Poland increased by 80% compared to the previous year, and in 2022, sales grew by 120% compared to 2021. Currently, heat pumps are installed in several hundred thousand households, and this number is expected to rise rapidly in the coming years.