Faculty;
of;
Urban;
Construction;
and;
Environmental;
Engineering,Chongqing;
University;
The;
Key;
Laboratory;
of;
the;
Three;
Gorges;
Reservoir;
Region’s;
Eco-Environment,Ministry;
of;
Education,Chongqing;
University;
Department;
of;
Civil;
Engineering,Luoyang;
University;
of;
Technology;
fresh-air; earth; energy; double; pipe; soil-air; heat; exchanger;