Changeover System with Reversible Heatpump

This system concept is aimed at slightly smaller systems where by using a reversible heat pump (that in one mode achieves a somewhat lower COP) the hydraulic design is much simpler. The interface with the building can be a plate heat exchanger (for water systems) or a coil in a Air Handling Unit (air systems). The AHU coil can then be used for heating or cooling, depending on the requirement.

The borehole heat exchanger may also offer a free cooling possibility. The system offers a competitive COP (> 4).

If peak shaving or backup capacity is required, the system can be extended by adding gas-fired or biomass boilers for additional heating capacity or dry air coolers for additional cooling capacity. Thermal solar panels or other sustainable energy systems can be integrated as well.


  • Capacity 30 kW - 250 kW
  • Sesonal changeover heating or cooling
  • High COP (> 4) possible.
  • COP > 20 during free cooling
  • Seasonal and diurnal energy store
  • Buffer capacity 0.5 - 1.5 m3
  • Energy exchange using high performance plate heat exchanger
  • Degassing & pressurisation included
  • Expansion facilities included
  • Hybrid options possible