Johnson Controls has announced that it is building a “custom-made” 42MW (11,942TR) ammonia heat pump system using six “high-performance” screw compressors for Zurich that will deliver district heating to 15,000 homes.
The heat pump will be used by Zurich’s Department of Waste Management and Recycling (ERZ), which is adding a third processing line to an existing waste incineration plant. As part of the utility’s waste-to-energy targets, the ammonia heat pumps will extract low-temperature heat from the new line’s flue gases to generate heat for the district heating network, with commission expected in 2027.
“We are proud to be partnering with ERZ on this innovative project, paving the way toward more energy-efficient and sustainable urban environments,” said Richard Lek, President of Europe, Middle East and Africa (EMEA) at Johnson Controls. “In 2024 alone, Johnson Controls helped cut customers’ expenses by 53% and reduce emissions by 60% compared to conventional natural gas boilers.”
The details: The heat pumps will be configured in three pairs, operating in series, with each set incrementally increasing the temperature.
- The company expects the design to boost efficiency by as much as 30% compared to managing the entire temperature lift in one stage.
- The ammonia units are positioned first in a set of multiple heat sources to increase the temperature supplied to the grid, according to the heat pump manufacturer.
- “The solution is one of the largest in Europe to use ammonia in a heat pump application on this scale,” Johnson Controls said.
Additional district heating projects: Johnson Controls has large-scale ammonia heat pumps operating in several European district heating systems.
- A 27MW (7,677TR)-capacity district heating network in the Netherlands uses four ammonia-based HicaHP Sabroe units to heat 20,000 households in Utrecht and Nieuwegein. The system, commissioned in September 2024, cuts the district’s annual CO2e emissions by 30,000 metric tons.
- An 11MW (3,128TR) ammonia system, consisting of three Sabroe ChillPac ammonia chillers and two Sabroe HeatPac ammonia heat pumps, provides heating and cooling to a 330,000m2 (3,552,090ft2) hospital in Aalborg, Denmark, which opened in 2024.
- A 700kW (199TR) two-stage Sabroe-branded ammonia heat pump in the town of Neustadt in Holstein, Germany, uses the Baltic Sea as a heat source to provide heating and hot water for businesses in the harbor district and 700 to 800 households.
Increasing manufacturing: In July, Johnson Controls announced the expansion of its Holme facility in Aarhus, Denmark, to increase the production of its large-scale Sabroe-branded heat pumps for commercial and industrial applications.
- The brand manufactures ammonia, CO2 (R744) and propane (R290) heat pumps and chillers.
- With an expected completion in early 2026, the expansion will add 2,300m2 (24,560ft2) of manufacturing space and 1,800m2 (19,375ft2) for testing high-capacity equipment in simulated real-world conditions.
Quotable: “The city of Zurich is actively committed to achieving net carbon neutrality by 2040, [in part by] increasing the use of carbon-free heat,” said Jürg Bruder, Head of Major Projects at ERZ. “By teaming up with Johnson Controls, we’re paving the way toward a more sustainable future.”
“By teaming up with Johnson Controls, we’re paving the way toward a more sustainable future.”
Jürg Bruder, Head of Major Projects at ERZ
