Air-conditioning equipment using underground air as the heat source

A cooling and heating apparatus using underground air as a heat source is provided to connect an underground air suction pipe buried to a gravel layer and a porous layer not influenced by external air with a second heat exchanger of a heat pump to supply air relatively hotter than external air in winter and relatively colder than external air in summer to obtain cold water and hot water through a first heat exchanger, thereby performing efficient cooling and heating all the year around. A heat pump(10) has a compressor(13) and an expansion valve(15) connected with a first heat exchanger(11) and a second heat exchanger(12) through a four-way valve(14) to obtain cold air and hot air. An underground air suction pipe(17) is connected with the second heat exchanger, wherein the underground air suction pipe is buried to a gravel layer and a porous layer not influenced by external air. A line(20) is installed at the first heat exchanger for supplying water to obtain cold water and hot water. A third heat exchanger is installed at the line of the first heat exchanger, having a third blower fan. A ventilation duct is connected with the third heat exchanger to a building to be cooled and heated. A return duct is connected from the building to the third heat exchanger.