Optimization of energy used for ventilation and air conditioning and re-structuring of district heating

METRO Group Asset Management has around 1,000 employees and runs over 650 commercial properties, mainly as retail outlets. The Walzmühle property in Ludwigshafen is one of the company’s medium-sized shopping centres, with 25 different stores.

An energy audit discovered that the building technology systems in Ludwigshafen, which were taken over in 1999, were considerably over-sized and that the control systems needed overhauling. A variety of measures were used to put an optimized energy concept into place. The measures implemented included the conversion of the ventilation system, which had previously used outdoor air only, to a mixed air system, including adaptation and regulation of the amount of incoming and outgoing air for the different areas in the building based on actual ventilation requirements. At the same time the district heating was decoupled for the generation of hot water and heating. These measures, which required investments of around 230,000 euros, resulted in energy savings of 800,000 kWh electricity and 1.7 million kWh district heating, which is equivalent to cost savings of 200,000 euros per annum. The repayment period thus amounts to 1.1 years, with a return on investment of almost 90%.