Aller-Weser-Klinik GmbH, Achim, Lower Saxony, Germany

Renovation of the hospital engineering at the Aller-Weser-Klinik


Lower Saxony’s Aller-Weser-Klinik, as the hospital network of the Achim and Verden hospitals, serves all major medical care specialties with around 145 beds in each facility.

Aller-Weser-Klinik gGmbH, Achim, Germany


Due to limited budgets of recent years, the clinic had an immense backlog of investment in terms of the technical building equipment. Since the initial installation in the seventies, only a few components have been replaced in the existing heating, ventilation, and air-conditioning systems. As a result, the energy consumption and CO2 emissions were correspondingly high. A cost-neutral modernization of the technical building equipment was therefore urgently needed.


The energetic modernization of the building management system was implemented in an energy-saving partnership with Siemens. A cogeneration plant for power generation and utilization of waste heat was installed. The boilers were replaced and aligned with the actual needs of the facility. New, energy-saving heating pumps were purchased, and the volume of continuously flowing heating water was reduced. In addition, the air-conditioning systems were completely replaced. With the installed heat recovery technology, significantly less heat is lost than was previously the case. The necessary cooling is no longer generated by outdated equipment, but by a modern refrigerating machine with lower energy consumption.


Continuous measurement of energy consumption forms a solid basis for further optimization measures – without compromising the comfort of the patient. The energy costs and CO2 emissions were significantly reduced in this manner. In this way, the clinic makes a significant contribution to climate protection.
A so-called Green Building Monitor at the entrance of the clinic also informs patients, visitors, and employees constantly on the building’s efficiency, thus making the achievements transparent.


  • Significant reduction in energy costs

  • Reduction of CO2 emissions by 50%

  • Reduction of electricity purchased from the grid by almost 75%

  • Significantly less heat loss due to heat recovery technology installed

  • No loss of comfort for the patients

  • With the Energy Saving Performance Contracting model, necessary investments can be financed within 10 years through the savings achieved