The invention relates to filtering which is building an air filtering chamber connected with plural air inlet pipelines under plant gardens and rest places in housing estates and public places in the city each, using high pressure device to input he air from the pipelines into the first circulating pool for filtering (connected with a deposition tank), inputting the filtered air into the second pool, the third pool, the fourth pool, etc, for filtering, so as to make the high temperature, dry, polluted air become the clean, low-temperature air, which enters into the in-bore underground water for filtering and cooling, and finally feeding the well water-filtered air to huge numbers of families. The underground mine thermal spring water is undrinkable, and by heating principle, the steam is converted into water for circulating heating, and the used cold water is fed back to the source through filtering and depositing pools and pressure device, so as to protect the original features of the underground water. |