PROJECT
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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.
www.plumbingafrica.co.za
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