Plumbing Africa June 2018 | Page 47

PROJECT 45 << Continued from page 43 PRODUCTS USED DURING THE PROJECT “We proposed the usage of a PEX piping system for the hot/cold/grey/rainwater systems, based on our desire for a system with a good low-maintenance track record, as well as removing any temptation of theft of any copper or brass supplies from the project,” explains Clint Morck, the wet services engineer from Delca Systems. Geberit’s Mepla was agreed on by both engineer and contractor (this is an NEC3 contract whereby both sides of the contract are required to work in conjunction). HDPE piping was specified for the outside of the buildings, and for the greywater collector lines in B001. “The supply of pumps was left to the contractor’s decision — in accordance with the NEC3 contract, based on our input/output requirements,” says Morck. UNIQUE ASPECTS OF THE PROJECT This project has two unique features: the greywater system and the fire reticulation system. The greywater system recycles water from basins, showers, and all the washing machines. T he required flushing water volume is then filtered and processed through a Biobox system. This treated water is then pumped back into the different buildings to the respective toilet cisterns. All systems were designed using standard norms and regulations, except for the greywater and rainwater harvesting and supply, whereby header tanks on the roofs of the buildings were supplied with either treated greywater (B001/NBP001/NBP002) or irrigation supply (NBP003 to NBP013). The greywater will be stored in 1 000-litre Jojo tanks, with their own 1kW pressure pumps, and will only be used to flush toilets. The hot water plant and reticulation for B001 were unique in that it was decided to go with a centralised (heat pump and pressure vessel storage) plant under Block D of the formation, and ring feed the hot water to each of the six buildings’ service ducts. As a result, the lengths of the dead legs in the hot water supply were reduced. BACKUP WATER SUPPLY The university has their own supply reservoirs (3ML and 0.9ML) for backup water supply. “I am of the opinion that this storage volume has been projected to handle a two- day storage for the entire campus, once fully developed, due to the bulk water supply having been designed by a different engineer,” explains Morck. FIRE RETICULATION AND GREYWATER/RAINWATER SYSTEM Morck explains that the fire reticulation was handled by a separate fire consultant and is specific to each building, all pulling any necessary supply from the bulk water line through the campus. This draw (should there be no fires in the next few years) will only impact the initial filling up of the storage units. 1 1. 2. 3. The cleaners’ pan. Pot sink with a pull-out sink hose in the hotel school’s demo kitchen. Granite handbasin at the hotel school’s main kitchen. 2 3 Continued on page 47 >> www.plumbingafrica.co.za June 2018 Volume 24 I Number 4