Energy-Management for Buildings

Ecologically optimised generation of heating and cooling for the commercial sector

Optimising all components in the system substantially reduced both the energy needs and operating costs of a refurbished optician’s. 



Initial situation

Augenoptik Borstel GmbH in Grimmen planned to convert and extend their premises.  

Not only the sales and show rooms, but also the examination area and the workshop require very good lighting. These requirements cause high temperatures in the building and the rooms have to be air-conditioned or cooled throughout the year. 

Project target

A holistic energy concept was to be implemented during refurbishment to reduce the heating, cooling and lighting needs of the optician’s premises.

Under the project, the electricity output of the building’s solar power system was to be raised by approx. 15% by cooling the solar modules using well water available on the grounds. 

The aim of the energy concept was to reduce CO2 emissions by 90%.

Technical measures 

  • Heat insulation: the outer walls, basement ceiling and roof space were insulated. The new windows and doors were triple-glazed.
  • Heating: the existing gas central heating was replaced by a water-to-water heat pump. The heat is distributed through a capillary tube system inside the ceilings, and in part through the flooring and walls.
  • Construction of a well to operate the water-to-water heat pump and at the same time supply the water required to fully air-condition the building.
  • Air conditioning: the shop’s rooms are also cooled directly by the well water contained in the capillary tube mats integrated into the storey ceiling. This system replaces the conventional electric air-conditioning system. A heat exchanger helps to avoid potential contamination within the capillary tube system. The air conditioning is independent of the heat pump.
  • Systematic use of energy saving bulbs for interior and exterior lighting.
  • Solar power generation: installation of a photovoltaic system on the roof which inputs into the public grid. Half of the solar cells are cooled with well water to show the percentage by which the electricity output is raised when the cell temperature is reduced. For this purpose, capillary tube mats are laminated to the back of the cells.
  • In addition, a building management system monitors energy consumption.


These measures made it possible to achieve the following:

  • A considerable reduction in operating costs
  • The low maintenance and environmentally friendly operation of the whole system
  • The creation of a healthy work environment
  • The reduction of CO2 emissions by around 94% (CO2 emissions on site = 0)

The expected higher output from the cooled solar modules was not achieved. The higher output from the system amounted to only 1.166% throughout its operating life. 

More Project Informations

Project title:  Konzept zur ökologischen Wärme- und Kälteerzeugung durch Optimierung aller Anlagenbestandteile als Musteranlage für den gewerblichen Bereich

Project number:  20123

Project period:  2005 - 2008

Project region:  Germany (Mecklenburg-Western Pomerania)

Project contact:

Frau Fischer

This email address is being protected from spambots. You need JavaScript enabled to view it.

+49 (340) 2103 3067

+49 (340) 2104 3067

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Source:  Environmental library of the Federal Environment Agency (UBA)