Finland is installing the world’s largest air-to-water heat pump for Helsinki’s district heating, aiming to reduce CO2 emissions by 26,000 tonnes annually.

MAN Energy Solutions will supply a 33MW air-to-water heat pump unit to Finnish energy company Helen Oy as part of its Patola heating plant complex in Helsinki. The new heating plant, which includes the industrial-scale heat pump and two 50 MW electric boilers, is projected to reduce CO2 emissions by a total of 56,000 tons.

The unit can operate at outdoor temperatures as low as -20C, using CO2 as the natural refrigerant in a closed loop system. Powered by electricity from renewable-energy sources, the heat pump will utilise ambient air as a thermal energy source to increase the water temperature.

A standout feature of MAN’s solution is its use of toxicologically- and environmentally-safe CO2 as a refrigerant for the entire system-cycle, which allows to deliver heat at temperatures of up to 90C. Additionally, the solution enables rapid power-balancing of the electrical grid, supporting the integration of intermittent power generation like solar and wind.

Uwe Lauber, CEO of MAN Energy Solutions, said: “We are very proud to support Helen in their efforts to achieve carbon neutrality in Helsinki. Urban district heating projects that utilise climate-neutral technologies are essential for advancing global efforts to reduce carbon emissions. We are excited to see our heat pump solution play a key role in driving the energy transition forward.”

Helsinki has set a goal to become carbon neutral by 2030, and he Finnish Ministry of Economic Affairs and Employment has granted Helen an energy subsidy for the large-scale heat pump plant. The plant is expected to start production during the heating season of 2026-2027.

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