The Impact of Smoke Curtains on the Operation of ESFR Sprinklers in Terms of NFPA 204 and NFPA 13 Standards

Aim: The aim of this article is to answer the question whether in case of simultaneous use of automatic smoke extraction devices and a sprinkler system with ESFR sprinklers, the use of smoke curtains will affect the level of fire safety. Introduction: In large-scale storage facilities, automatic smoke extraction devices and fixed automatic water extinguishing devices are commonly designed, most often with ESFR sprinklers. When designing the above fire protection devices, it is necessary to take into account the possible interaction between both installations, and especially the undesirable interaction that could disrupt the operation of one of the installations. One of such elements affecting the operation of the sprinkler system is the use of smoke curtains, which are an element of the smoke extraction system. There are indications that in certain conditions, the use of smoke curtains may negatively affect the operation of the sprinkler system. Methodology: The following scientific methods were used: critical analysis – in relation to literature research, computational experiment – taking into account the equations of numerical fluid mechanics, comparative analysis – allowing for the assessment of the safety level based on the obtained calculation results. Conclusions: In the case of storage buildings, the priority is to effectively extinguish the fire in the initial phase using a sprinkler system. The literature has reported cases of fires in which smoke curtains had a negative effect on the activation of the sprinkler system, which is also confirmed by numerical analyses. An obstacle in the form of a smoke curtain can change the sprinkler activation area and the shape of the water jet itself. Smoke extraction devices should therefore be designed in such a way as not to negatively affect the effectiveness of the sprinkler system. The NFPA 13 standard explicitly states that smoke curtains should not be used when ESFR sprinklers are used. The lack of requirements for the use of smoke curtains in storage facilities was also introduced in the NFPA 204 standard. The use of smoke curtains in storage buildings equipped with ESFR sprinklers should only be implemented in strictly defined cases. In the current legal system, a designer with the authorization to perform an independent technical function in construction and a fire protection expert are fully responsible for the execution of the project in accordance with the regulations, principles of technical knowledge and fire protection requirements. In the design process, it should be taken into account that effective fire extinguishing in the initial phase is ensured by a sprinkler system constructed in accordance with the design standard and maintained in functional efficiency. Keywords: sprinklers, smoke venting, draft curtains, sprinklers and smoke venting interaction, ESFR Type of article: review article