thermea. installing Switzerland's largest CO2 heat pump system

By Sabine Lobnig, Apr 02, 2012, 00:00 4 minute reading

On 1 November 2011, a new thermeco2 heat pump system for hot water generation and heating was put into operation in the slaughterhouse Zurich. With a capacity of 800 kW, the plant is the largest ever built in Switzerland. The heat pump uses waste heat from the refrigeration machine, ventilation, and compressed air systems as sources that can generate temperatures up to 90 °C. In the overall balance of the slaughterhouse, CO2 emissions can be reduced by approx. 30 %. By

ewz (Elektrizitätswerk der Stadt Zürich), Swiss energy provider and owner of the slaughterhouse Zurich, has several reasons to decidte for a converions of the the slaughterhouse from former steam boiler heating to a high temperature heat pump system by thermea. Energiesysteme GmbH with CO2 as a refrigerant.

Higher efficiencies

Slaughterhouses have high demand of high temperature hot water. The efficiency advantages of the high temperature heat pump system had therefore clearly priority. The thermeco2 machines deliver the required 90 °C, accurate to the tenth degree, and with better COPs compared to other refrigerants. Better COPs are enabled by the specific thermodynamic properties of the CO2 refrigerant. Under the appropriate operating conditions, the transcritical process control on the high pressure side, as it is mastered by thermea. in its thermeco2 large heat pump range up to well over 1,000 kW, has significant economic benefits. ewz therefore expects higher efficiencies with this CO2 system than would be possible with comparable HFC-systems.

ewz had furthermore set the clear objective to use climate friendly refrigerants and wanted to make use of the waste heat from the refrigeration processes. Additional advantages thanks to the CO2 system are reduced use of water and higher operating reliability.

Safety & noise & maintenance

CO2 has the advantage of minimal safety requirements. The avoidance of costs for foundations and noise control measures is due to the low-noise and low-vibration operation of the thermeco2 machines. In conjunction with the extremely low space requirement, this large heat pump system could be installed in a container system on the roof of the slaughterhouse in a short distance to urban residential development. Only authorised personal has access to the container and CO2 sensors have been installed that activate an alarm when healthy concentration levels are exceeded.

The risk for leakage is considered small by ewz as the installed system has been certified and optimised for high pressures. A fine performance graduation without loss of efficiency and the high reliability are further advantages of the technology supplied. Maintenance and repair costs for the heat pumps are also low due to the use of virtually maintenance-free compressors.

System specifications
  • Refrigerant: R744 (carbon dioxide)
  • Refrigerant charge: ~ 225 kg
  • Machine type: 3 x thermeco 2 HHR 260
  • Capacity control via master CPU: adjustable in 12 stages
  • Total heating capacity: 800 kW at 90/30 °C
  • Total refrigerating capacity: 564 kW at 20/14 °C
  • Electrical power consumption: 237 kW
  • Heat pump COP: 3.4
  • Annual heating output: 2,200 MWh
  • CO2 emission reduction: 510 tonnes/year
Involved companies

The system was supplied by thermea. Energiesyteme GmbH. The manufacturer of thermeco2 high-temperature heat pumps is a medium-sized company based in Freital, Germany, with production facilities in Ottendorf-Okrilla near Dresden. Founded in 2008, the company builds on 30-year experience in refrigeration and heat pump field.

If you would like to contact thermea. Energiesysteme GmbH for any enquiries, you may send a request to Steffen Oberländer directly.

The initiator of the project was ewz, owner of the slaughterhouse Zurich. ewz designs and develops, in collaboration with its customers, solutions for the supply of their buildings with heat, cold, conditioned air and other media. For this, ewz designs, finances, builds, and operates the power systems that are in its possession. ewz says to be open for installing more CO2 systems whenever the plant requirements allow it.

The project was planned by the specialist consultant Kurt Weiss GmbH in Schlieren, Switherland.


The slaughterhouse Zurich, opened in 1909 as a municipal supply, has been run by Schlachtbetriebe Zürich AG since 1995. The city of Zurich, represented by the Umwelt- und Gesundheitsschutz Zürich (UGZ), is the owner of the land and the buildings. For a long time, the UGZ and Schlachtbetriebe Zürich AG have tried to reduce energy consumption and CO2 emissions by a variety of measures and thus make a further contribution to the "2000 Watt Society". "Energy analyses have shown that the hot water could be produced much more ecologically. That is why we have grasped the opportunity with both hands and decided to supplement the gas heater with a heat pump," Councilwoman Claudia Nielsen said in a media tour. ewz was subsequently commissioned by the UGZ to create and operate an environmentally friendly energy supply system for heating and hot water. The heat delivery by ewz is part of an energy contract. ewz planned, financed, built, and operates the heat pump system that is in its possession. By this environmentally friendly energy supply in the slaughterhouse, the UGZ, the slaughterhouse Zurich, and ewz make an important contribution towards the "2000 Watt Society" of the city of Zurich.

About thermea. Energiesysteme

The manufacturer of thermeco2 high-temperature heat pumps is a medium-sized company based in Freital with production facilities in Ottendorf-Okrilla near Dresden. Founded in 2008, the company builds on 30-year experience in refrigeration and heat pump field.

thermea. Energiesysteme earned recognition for thermeco2 innovative system that uses carbon dioxide as working fluid when the company received the ‘Cold Award’ from the German Federal Ministry for Environment, Nature Conservation and Nuclear Safety.

Contact information

If you would like to contact thermea. Energiesysteme for any enquiries, you may send a request to Stefan Oberländer directly.

(Source: ewz Pressemitteilung)


By Sabine Lobnig

Apr 02, 2012, 00:00

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