Impact of supply and exhaust ventilation system on gas concentrations in a compartment during thermal decomposition and combustion of materials

Experiments were conducted on the detection of fires when using different operation modes of an indoor supply and exhaust ventilation system. The operating conditions of the supply and exhaust ventilation system were identified that exclude the formation of hazardous concentrations of products of thermal decomposition, gasification and combustion of class A materials (wood, cardboard and linoleum). The changes in the concentrations of the gas-air mixture components (CO, O2, CO2) were recorded in different operation modes of the supply and exhaust ventilation system and for different mechanisms of thermal decomposition and flame combustion initiation. The performance characteristics of the supply and exhaust ventilation system were determined that are necessary and sufficient for efficient operation of fire detection, containment and suppression systems. [Display omitted] •Supply and exhaust ventilation allows faster detection of pyrolysis and combustion.•Efficient position of ventilation ducts was determined.•Relationship between fire detector location and ventilation conditions was established.•Different effects of ventilation on CO, CO2 and O2 variation rates were identified.•Equations linking fire detector activation to ventilation parameters were derived.