JC heat pumps in Zürich district heating expansion
2nd September 2025
SWITZERLAND: Ammonia heat pumps from Johnson Controls are to be employed in an expansion of a Zürich waste incineration plant supplying the city’s district heating system.
The project, spearheaded by the municipal utilities of Zürich ERZ, entails the expansion of the
Hagenholz plant, near Zürich airport, with a third process line and heat recovery from the flue gases.
Johnson Controls will supply six screw compressors with a total output of 42MW to upgrade low-temperature heat from the flue gas of the incinerator.
To maximise the waste heat extraction and further increase efficiency, the units will be applied as three pairs of heat pumps operating in series, reducing the lift required.
The recovered energy supplied to the district heating network will provide additional heat to around 15,000 homes. Due to start operations in 2027, the project is said to be one of the largest in Europe to use ammonia in a heat pump application on this scale.
