The world’s largest air-to-water heat pump is expected to become operational in the 2026-2027 heating season and keep about 30,000 households in Helsinki, Finland, warm. The district heating system, which will include an industrial-scale heat pump and two 50 MW electric boilers, is also projected to reduce carbon emissions by 56,000 tons per year.

German manufacturer MAN Energy Solutions is to supply a 33 MW air-to-water heat pump — the world’s largest ever used for a district heating plant. The unit will operate at a capacity of 20 MW to 33 MW under outdoor temperatures as low as -20° C, using carbon dioxide as the natural refrigerant in a closed loop system. The heat pump is to be powered by electricity from renewable-energy sources and utilize ambient air as a thermal energy source to increase the water temperature and meet district heating network requirements.

The heat pump solution delivers heat at temperatures of up to 90° C while also enabling rapid power-balancing of the electrical grid. A hermetically sealed high-speed oil-free integrated motor-compressor with active magnetic bearings eliminates the need for a dry gas seal system in a small footprint.