Approaches taken to mitigate fires in buildings are multi-faceted , and include active measures such as smoke detectors , fire alarms , sprinkler systems , smoke extraction and evacuation protocols . Passive measures include fire containment through fire-resistant walls , roofs , floors and the installation of fire doors , along with clear signage to show accessible fire escape routes . Fire engineering starts with looking at the most probable fire scenarios – for instance , Karel Roodt , director and engineer at The Fire Engineer , points out that it serves no purpose in a steel manufacturing warehouse to have a fire protection system dependent on sprinklers because there is nothing that can burn . The sprinkler system could end up creating more damage to sensitive equipment .
An important component of fire engineering is to prevent the spread of fire within a building . By containing the fire , further damage to the building is prevented while minimising the heat build-up and deadly smoke emissions .
Fire engineering is not just about designing a sprinkler system , or a smoke detector system : it involves looking holistically at the unique fire requirements of each premises . “ For this reason , legislation requires that a building ’ s fire system be designed by an ECSA qualified fire engineer , of which there are two types : a fire system installation engineer and a fire safety engineer who designs the safety process .” The differences are spelled out in greater detail below .
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When planning a concept engineered fire suppression system , numerous aspects are taken into consideration : life safety , systems effectiveness based on the combustible product ( i . e ., fire load ) and processes , business continuity , building protection , environmental impact and cost . . A cold store or food production facility is likely to undergo severe damage by a sprinkler system using water – a clean agent could be a possible solution but extremely costly – and therefore a perfect fit for an engineered system looking at a hypoxic system for cold rooms .
FIRE DAMPERS
Fire dampers save lives by reducing the risk of smoke and of fire spreading through a building when disaster strikes . Its attraction is that it is fitted with a fusible link that shuts off the damper whenever the temperature at the damper rises above 72 ° C , says Christiaan Bosch , MD of Rickard Air Diffusion .
The damper can also be fitted with a motor that allows the building management system to control smoke and fresh air movement in a building during different stages of a fire . Keeping smoke away from the areas with no fire and extracting smoke from areas that had a fire can save lives .
“ Even when there isn ’ t a fire , you can use it to control the amount of air allowed through the duct as a form of volume or pressure control . A fire damper is a product built of quite thick steel compared to other damper products , ensuring the damper can withstand fire for some time and protecting
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the occupants of the building from smoke and fire – though its purpose is not to put out the fire . It has been SABS tested to resist fire for two hours ,” says Bosch .
He describes such a system as being appropriate to any building where the air conditioning is centrally located , or any system where air is distributed to different parts of the building . “ Fire dampers are needed wherever the air moves through a firewall , partitioning the building into different fire sections , so that it can be cut off from the rest of the building to reduce the risk of a fire spreading .
“ While steel fire dampers are cost effective , they are more expensive than normal pressure control dampers , as they have to be more robust to withstand the heat of the fire and they incorporate an automatic shutdown system .
“ There are different systems , some that prevent fires and others that aim to stop fires from spreading . Fire dampers are typically used in conjunction with other systems being appropriate to certain types of applications such as various sensors , sprinklers and control systems . It ’ s the integration of these different systems that make for a safe building ,” he notes .
The core function of a fire damper is to close down the ducting whenever the heat of a fire reaches 72 ° C in the duct – ranking as a substantial fire . “ These automatic shutdown systems cannot be electronic , or they could burn out , but fire dampers rather use a fusible link that melts at that temperature , bypassing all electronic systems and snapping shut .”
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Rickard Air Diffusion
Christiaan Bosch , MD of Rickard Air Diffusion .
“ Our fire dampers are tested to comply with SANS 193:2013 . The safety regulations in South Africa are good , and if the building owners employ consultants to design HVAC and fire systems to the relevant standards , building owners will own a safe building and occupants have the best chance of surviving if things go wrong ,” explains Bosch .
He notes that in Europe there are a number of innovations using different materials that aim at extending the time that a fire damper will survive in a severe fire . “ These do increase the cost of the system , while our standards in South Africa remain quite effective for performing this function . I believe in the future there will be more focus
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