EFFSYS2 is a Swedish research program, which started in 2006 until 2010. EFFSYS2 is the continuation of the earlier research programs “Alternativa köldmedier”, “Klimat 21″ and “eff-sys” that were first started back in 1994. These research programs have been very successful and have brought Sweden to the front of international research in the area of refrigeration and heat pumps.

Nowadays, Swedish research institutes have a strong international position in the area of refrigeration and heat pump technologies. This position shall be maintained and the research shall continue to develop in cooperation with the industry. This is a step in the switch towards a more sustainable and resource efficient society.

Our Project

The scope of our research activity within EFFSYS2 was on "Efficient use of energy wells for heat pumps"


The project aims to develop recommendations for the design and installation of collectors in boreholes for heat pumps. Several aspects are covered:

  1. Mapping of short circuit effects (internal heat transfer) of the collector and the methods to avoid these.
  2. Investigation of the performance of various embodiments of the collectors.
  3. Mapping of methods to ensure turbulent flow without causing unnecessarily high pump powers, ie the optimization of the flow.
  4. Identification of impact on the performance and cost of performing the drill hole / holes.
  5. Investigation of the heat absorption of two-phase thermosiphon (natural circulation).
  6. Investigation of the dynamic interaction between the heat transfer in the collector / borehole and heat conduction in the surrounding rock.
  7. Investigation of the effect of the re-storage of different types of energy wells.

You can find further information about this project in this section. 

Conference and Journal  publications resulted from our investigation can be found in Publications .

Belongs to: Department of Energy Technology
Last changed: Mar 24, 2016