Gas hot water heater
Appliance for heating domestic water with the pass-through or instant tankless principle.
Geothermal heat pump
System for using geothermal heat for heating homes and buildings.
To use heat energy, U-shaped plastic pipes of generally up to 1330 ft. are inserted vertically into the earth. A cold brine (=water alcohol mixture) circulates in the pipes, which takes up the heat from the earth.