Plumbing Africa August 2018 - Page 63

PROJECT 61 << Continued from page 59 Fortunately, with assistance from the architect, a dead space was optimised for the rainwater harvesting plant. A few stormwater pipes were diverted to the plant, including the main sump that gathers the groundwater to the rainwater harvesting plant. A large percentage of water wastage occurs in pipe leaks. To monitor this, WSP designed the system to have water meters that link to the BMS and to the incoming council mains to ensure that if there are any irregularities, they are detected and addressed. WSP Wet Services gives liberty to the plumbing specialists to select reliable equipment to meet the performance criteria, as per its designs. The equipment selected were as follows: 1 Domestic cold water plant Domestic cold water tanks JoJo Tanks 20 000 litres (two) Domestic booster pump set Grundfos Hydro MPC-E 3 Domestic booster pump set BMS communication Grundfos CIM 500 Bulk water meters Sensus Meistream Ultrasonic level sensor Vegason-61 with Veganet-381 Communicator Domestic hot water plant Domestic hot water vessels SA Heat Pump 1000 litre vertical tanks Domestic heat pumps SA Heat Pump BWHT4 Domestic hot water circulating pumps Grundfos Magna1 Bulk water meters Sensus Meistream Temperature probe sensor Rainwater harvesting plant ETF NTC 10k Temperature Domestic catchment tank Abeco sectional steel tanks Irrigation tanks JoJo Tanks 5 000 litres (ten) Domestic booster pump set Grundfos Multi-E2 Bulk water meters Lift pit sump pumps Sensus Meistream Lift pit pumps Grundfos Unilift AP12 Lift pit sump pumps BMS communication Grundfos LCD 108 controller As a collective effort between WSP Wet Services, WSP Sustainability Consultants, and Boogertman + Partners, low-flow fittings were selected to serve the ablutions and pause area in an effort to use water efficiently. The hot water system is based on SANS 10400: XA, which states: “50% of all annual hot water generation is to be of a renewable source other than electrical elements.” The renewable energy equipment used are heat pumps, which have a coefficient of performance (COP) of 3:1, which contributed to the low electrical usage. 2 The domestic cold water plant was put to the test as Bryanston experienced municipal water cuts. Since the surrounding buildings could not operate, Knightsbridge managed to withstand the scarcity and lasted for three and a half days before Joburg Water reinstated the municipal incoming supply. As the system settles, WSP, along with the contractor, will have the opportunity to finetune the building function of the wet services. So far, the system has been in operation for nine months and all of the client’s desires have been met, with new tenants occupying the available spaces. PA 3 1-2. Some of the rainwater harvesting installations. 3. Hot water plant. August 2018 Volume 24 I Number 6