Project
© RACA Journal | Benjamin Brits © RACA Journal | Benjamin Brits © RACA Journal | Benjamin Brits
48 does however include costly up-front capital investment on the equipment side , so benefits are only realised down the line .
Part of the client brief was that each unit would receive gas in the form of cooking points and therefore would require adequate ventilation to manage the standards associated with gas that would run throughout the building . As part of this project too , ACS was to incorporate different air extract
The completed gas boiler plant room .
The gas boiler flue extract fan with pressure / flow switch to stop boilers in the event of a fan failure .
The ducting handling the future restaurant kitchen canopy extraction .
RACA Journal I May 2022 systems and basement extraction ( being underground ), where implementation would handle the building requirements for extraction of smoke and general ventilation .
Only the penthouses would receive their own dedicated air conditioning systems as requested by the client / developer .
THE HVAC SYSTEM This project included to a large degree a complex ventilation system . This involved the basement extract system that ACS had to design which incorporated smoke clearance and general ventilation into one system – making this less complicated , but also more cost and energy efficient . Basement areas were also fitted with CO and NO 2 sensors . The basement extract supplier also included computational fluid dynamics ( CFD ) in their service .
NO 2 sensors were included because of the growing number of diesel vehicles in use where NO 2 is a by-product of these combustion engine types , while CO is a by-product of both petrol and diesel engines – thus catering to both scenarios .
The basement also included the installation of smoke curtains serving four zones in this area ( less than 2000m 2 each ). If there is a fire in one zone , the fire curtain will drop and isolate that zone to eliminate the spread of fire or smoke to other zones , which then allows for the process of evacuating occupants safely . These work in conjunction with each zone ’ s extract / jet fan system . The basement smoke clearance system was designed according to SANS10400 part T4.42 , EN 12101-3 , SANS 1238 and BS 7347-part 2 , part 7 section9 .
Traditionally in smoke extract conditions , if inadequate extract venting is achieved , the smoke temperature exceeds the maximum of 300 ° C and can reach in excess of 600 ° C which will then cause flashovers . If the oxygen levels are very low , backdraught will occur hence oxygen introduced suddenly at a late stage may cause an explosion , hence the inlet of fresh air via the ventilation shafts .
All of the staircases had to also be pressurised as fire safety requires that one pressurises any escape stairs to eliminate ingress of smoke into these zones . The pressurisation of the staircases was calculated and designed according to SANS 10400 Part T and EN 12101 .
Part of the Ventilation system also included the management of air using an ozone unit . This site has a main refuse yard where the dustbins get stored before removal . Obviously , this type of area produces unpleasant smells for residents as well as the community generally , so to combat this the project included extract fans and integrated an ozone treatment system to supply ozone into the refuse room . Ozone has the property of neutralising unwanted smells .
An ecology unit was installed that caters for the restaurant kitchen extract canopies so that air can discharge at low level ( the kitchen will be located on the ground floor and is part of a future phase ). The ecology unit cleans up extracted air associated with the cooking of food ( removes smells and grease / oil / fat
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