The functional principle – proven millions of times over
With an air / water heating pump heat is "pumped" from the ambient air into the heating system using auxiliary electrical energy. This principle is already well proven with the reverse use for air conditioning or refrigeration systems.
The refrigerator removes the heat from its interior and emits it into the surroundings. The heat pump removes the heat from its surroundings and emits it into the heating.
As a heat source, we use the ambient air which always obtains its heat from the sun. This is why we call our air / water heat pump: HPSU 
