What type of piping is used? Service life of piping How is the piping installed? What heat transfer medium is circulated in the pipe systems? What type of antifreeze is used? What energy yield can be expected? What type of foundation structures can be used? What is direct cooling? What does an enercret system cost? What are the main benefits? Can the system be used for existing buildings? What is the difference between absorber piles and bore hole heat exchangers? What types of building is enercret suitable for? What type of piping is used? High Density Polyethylene (HDPE) piping, DN 20/2.0 and/or 25/2.3 mm. Service life of piping In view of the low pressures involved, the fact that it is always the same medium being circulated and the piping is embedded in the concrete, the service life of the piping can match that of the concrete. How is the piping installed? On the inside of the reinforcing cages and/or in the lean concrete layer beneath the foundation slab. What heat transfer medium is circulated in the pipe systems? As a rule a mixture of water and antifreeze. If the system is used for cooling only, it may be operated with water. What type of antifreeze is used? Mostly an antifreeze which is generally recognized as physiologically safe (food grade) and based on propylene glycol, such as Antifrogen L from Hoechst Chemie. Antifreezes which are based on ethylene glycol such as Antifrogen N have better physical properties. What energy yield can be expected? That will very much depend on the type of ground layers, moisture, period of use, type of use, etc. Meaningful figures can only be given on the basis of a simulation. As a very rough ball park figure, you can assume 40-60 W/linear metre of pile or 15-30 W/m² absorber-fitted surface area. What type of foundation structures can be used? In principle, all ground-contact concrete structures can be used, in particular concrete piles, diaphragm walls, piled retaining walls and foundation slabs. The prerequisite is a reinforcing cage. In addition, it is possible to equip all types of hollow piles with piping systems similar to bore hole heat exchangers. What is direct cooling? The cool ground temperatures (approx. 12 degrees Celsius) are used directly for cooling the building - without a refrigerator unit. What does an enercret system cost? That will depend on a whole series of factors and will have to be calculated for the individual project. Generally speaking, you can assume approx. EUR 500 per installed kW, while this kW figure can be applied for heating and for cooling. What are the main benefits a) Savings in running costs through savings in primary energy thanks to "direct cooling" and use of the heat pump. b) Up to 80% reduction in CO2 emissions through savings in primary energy. c) Assured supply as the energy source is underneath your own building and regenerates itself. d) Safe system with long service life. Can the system be used for existing buildings? Unfortunately not, as it is incorporated in foundation elements (ground-contact structures) required by the structural design of the building. What is the difference between absorber piles and bore hole heat exchangers? In the case of absorber piles the system is incorporated inside the reinforcing cages. With bore hole heat exchangers, the holes have to be drilled in the ground. The costs per kW of installed capacity is roughly twice as high for bore hole heat exchangers. What types of building is enercret suitable for? Enercret is suitable for all types of building. The prerequisites are suitable foundations, the early involvement of a specialist enercret consultant and preferably a low-temperature heating system for the building which can also be used for cooling (floor slab cooling/heating, floor heating, concrete core activation). Air heating/cooling is possible but less advantageous.