PURPOSE: To provide a highly reliable heat storage water tank in which contact between an insulating layer and water is prevented even when water penetrates close to the insulating layer and moreover the insulating layer is prevented from coming off in fragments.
CONSTITUTION: The subject relates to a heat storage water tank 1 which consists of a concrete chamber 5 built with an insulating layer 6 on the bed and a waterproof layer 7 on the insulating layer 6, has a drainage part 15 close to the tank, and is designed to store heat-storing water in the chamber. Between the bed on which the chamber rests and the insulating layer in this heat storage water tank a draining layer 18 is provided, in which drain channels 18c..., 18d... extending lengthwise and breadthwise are formed along the inner wall of the chamber. This draining layer consists of a board having many projections on the front side and on the back side in a rise-and-fall pattern and formed of a material which is impermeable to water. This draining layer has a drain channel which communicates with the drainage part 15 by a communicating channel 17 of the chamber.
TAKAHASHI HIDETOSHI
NAMATAME YASUSHI
