E2 (MWR) YSK-4477, REPAIR HOT WATER SYSTEM GRIDLEY CDC

The new hot water tank will require a large installation space and may interfere with the following existing objects. Therefore, it is required the detail research during design schedule. The renovation ideas are as follows: [Idea-1, permanent plan] 1) The following equipment needs to be removed: Existing hot water tank (1,000 L), hot water pipe among heatpump water heaters and hot water tank, and related piping. 2) Existing two heat-pump water heaters and temperature control valve are reused for the 43°C (110 F) line. 3) New hot water tank (6,000 L) and shed (with ventilation and light) on outdoor is provided for the 43°C (110 F) line. 4) Existing circulation pumps in the mechanical room are replaced for the 43°C (110 F) line. 5) New heat-pump water heater with enclosure on outdoor is provided for the 60°C (140 F) line. 6) New hot water tank (4,000 L) and shed (with ventilation and light) on outdoor is provided for the 60°C (140 F) line. 7) New circulation pumps in the mechanical room and hot water return piping are provided for the 60°C (140 F) line. 8) The related pipe with insulation is provided from the shed to the mechanical room and then to the required location. 9) The pipe trench is provided from near the wall surrounding the existing heat-pump water heater to near the shed. The related piping is provided from the mechanical room to the shed. The two existing trees near the wall surrounding the heat-pump units would need to be relocated. 10) Temporary electric hot water tanks for kitchen are provided. They are removed after construction. 11) The DDC needs to be modified to match the new system. [Idea-2, permanent plan] ... NOTE: description has been truncated, please see Project Note for full description.