| 摘要 |
Disclosed is a water tank system (1) comprising a water tank (2) arranged below a ground surface (3), wherein the water tank (2) is arranged for collecting rain water from an above ground surface (21, 22) during a rain fall. The water tank system (1) further comprises a drainage conduit (4) enabling fluid communication between the water tank (2) and a water distributing facility (5) and drainage means (6) arranged to control the fluid communication. The water tank system (1) also comprises a heat pump (7) arranged to use water in the wa-ter tank (2) as a heat source, and control means (8) comprising calendar means (9), where-in the control means (8) is arranged to control the drainage means (6) in accordance with the calendar means (9) so that the drainage means (6) is only activated if a current date of the calendar means (9) is within a predefined time period. A method for operating a water tank system (1) and use of a water tank system (1) is also disclosed. |
