PROJECT 21
Cold water supply from Council was suspended in an 80mm galvanised line feeding to a built-in concrete storage facility with 80mm modulating valve to fill . Also installed a bypass line to feed the building directly for emergencies .
Potable water was pumped using 100mm galvanised pipe , suspended in basement , ranging in sizes from 50 – 100mm , feeding individual ducts for the building , and in addition an individual 100mm supply to the roof top to feed hot water system directly .
For piping to the rooms , copper pipe , 15 – 42 mm , was installed .
For the Drainage HDPE cast in waste pipes were used . For noise sensitive areas such as passages and meeting rooms , Valsir PP3 pipes with acoustic value were installed and followed by an Isomat wrapping . For the non-noise-sensitive areas , conventional PVC pipe was used .
From heat pumps to heat accumulator tanks .
All drainage in the basement was suspended in PVC .
“ The uniqueness of this installation was the design , said Mike , because the building will always achieve the same pressure and demand of water whether one is on the ground floor of fourth floor . This means no complaints about pressure problems from clients .”
Pumps were installed in the basement which are used to pump water directly to the roof top hot water storage facility , as well as serving the building with both hot and cold water . The ring feed principle was applied enabling the pumps to continually feed hot water to all the floors at any given time .
The cold water is pumped directly from basement feeding individual ducts and pumped to the fourth floor where it ends .
3G Plumbing was also responsible for the fire piping . “ The fire system for the building used 100mm black steel piping and serves the building with hydrants and fire reels on every floor . Each floor has 4-5 hydrants and 7-8 firehose reels with 2 4.5kg extinguishers built into Fire Cabinets .”
In addition , the fire system has a booster pump installed allowing for inadequate pressure , should the need arise , from council mains . This pump is fed from a concrete water storage tank .
In keeping with SANS 10400 XA where 50 % of hot water generation must be alternative source , heat pumps were installed to indirectly heat the hot water for guest use . The heat pumps heat up the stored water in the storage heat accumulator tanks . The potable water passes through the heat exchanger coils producing hot water effectively limiting the loss of hot water when compared to a conventional boiler system .
The rainwater collection system is conventional and was installed with Fullbore outlets from the roof top . The water is discharged down ducts and suspended in the basement feeding into a concrete retention tank . At the basement level there are stormwater catch pits which discharge into a sump provided with large pumps to discharge to a concrete retaining tank to with other rainwater from the building .
Hot water storage heat accumulator tanks .
The sump has four pumps installed with three of the pumps having a discharge pipe diameter of 250mm and fourth one has a discharge diameter of 100mm . The total flow rate possible is over 100l / sec .
All water and waste installations were done to SANS standards and a Certificate of Compliance ( CoC ) issued .
Mike summed up the installation as , “ The difference ( of the project from a plumbing perspective ) was seeing how the different products can work together to achieve the best results , as well as the saving of money . Also seeing the result and how the system operates . It is like the final piece of the puzzle – always satisfying to see the project come together and working to plan .” PA
“ The potable water system was constructed from ground up using a selection of materials that suited the application .”
July 2021 Volume 27 I Number 5 www . plumbingafrica . co . za