The self-circulating CO2-ground probe (CO2-Heatpipe) was developed by M-TEC in  1999 and has been patented for exclusive use across Europe.
The CO2-ground probe uses CO2 (carbon dioxide) as heating media. The CO2-probe works on the heat pipe principle. The probe pipe contains both liquid as well as vapourous CO2. The liquid carbon dioxide is located in the bottom part of the probe, the vaporous CO2 in the upper part. 



By absorbing geothermal energy, the liquid CO evaporates, rises and gives off the geothermal heat in a heat exchanger to the working appliance of the heat pump. Due to this heat emission, the CO2 becomes liquid and flows down in the probe pipe. The CO2 is heated by the soil, where it again evaporates and rises and the cycle of. Continuous circulation is initiated. 
In contrast to the conventional Sole-ground probe, no energy source pump is required due to the self-circulation.   
Advantages of the CO2 ground probe: 

  • natural heating media (usage possible in water protection areas) 
  • high operational safety (no moving parts)  
  • lowest operating costs (no energy source pump) 
  • no antifreeze required (increasing durability)


The cooling heat technologies group (Energy Saving System) was developed by M-TEC in 2003 and is patent-protected. In cooperation with the company Hauser refrigeration technology GmbH, we refined the system to make it ready for commercial levels of production. Meanwhile, more then 100 supermarkets such as Spar, Hofer, Penny, Lidl, Wedl, MPreis and Sutterlütty utilize the system in their in operations.  

Heat recovery in supermarkets 

Consumers demand a large selection of various products with flawless quality. Dairy products, fruits and vegetables, meat and sausage products as well as deepfreeze products demand optimal cooling. This high cooling demand causes much exhaust heat, which is normally blown out into the open unused. In order to use this exhaust air effectively, M-TEC developed the Cooling Heat Group.

With this system the supermarkets are heated via the refrigeration plant, which allows them to eliminate a conventional heating system. The exhaust heat of the refrigeration plant is used for heating, instead of blowing it into the open unused, thus saving up to 100% heating costs. 

On very cold winter days, when the exhaust heat of the refrigeration plant is not sufficient, the missing heat energy is gained from ground probes. This heat pump function augments the Cooling Heat Group energy.  

The cooling heat group was developed by M-TEC and is patent-protected. Meanwhile, more than 100 supermarkets of Spar, Hofer, Penny, Lidl, Wedl, MPreis und Sutterlütty are in operation. And for the development of this system, we were awarded the Enenrgy Globe Award in 2006. 

Hartl (1) Hartl (2) Hartl (3)


By reducing operating costs, the competitiveness of your company can be increased sustainably and the dependence on rising energy prizes reduced. Exhaust heat and ambient heat are forms of free energy, which should be used in an efficient way. 
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