Aerothermal energy is thermal energy (from the sun) that a thermodynamic heat pump draws from the surrounding air and then transfers to a heating system, using the same principle as a geothermal heat pump.
Contrary to the latter, an aerothermal heat pump can be installed on any type of terrain. On the other hand, this system is more visible and its efficiency is more sensitive to variations in outside temperatures.
The visible part of an aerothermal heat pump. © kassoulet CC by-nc-sa 2.0