1. In case of cooling demand: the heat extracted from the building during the summer months is stored in the buffer for use in the winter (in this way the number of heat collectors can be reduced)
  2. At the end of the winter: you then extract residual energy from the buffer at the moment that the buffer temperature has become so low that there is no longer any heat exchange (exergy). It is inefficient to use the buffer when loading it: the heat pump will then run a very low COP.