People hear about disasters that affect the whole world daily from various media sources. These disasters include natural disasters, disasters caused by mankind or a combination of the two. This includes the war that is happening in Ukraine. Many disasters can cause a fire to occur in buildings. With any fire in a building, a safe evacuation of people must be ensured. Thus, it is important to design buildings so that when people are evacuating, they are safe. Escape routes must ensure that all people can get to a safe place in a short amount of time. The article describes the options of creating protected escape routes (further PER), efficacy of ventilation systems of PER with regard to ensuring a quick and safe evacuation of people. The article also evaluates methods of natural ventilation on PER. To evaluate the efficacy of the ventilation of PER a mathematical model Fire Dynamic Simulator with an extension Pyrosim is used. Parameters important for the safety of people in PER are temperature, visibility and the volume of air flowing from the vents measured per a unit of time. The article also suggests a change to the established methods of ventilating the PER with regard to partial results obtained and proposes a new method of research that is focused on the safety of people when evacuating from buildings in danger of a fire.

A small quantity of flammable gas mixed with dust can cause a large explosion with severe consequences. In this study, hybrid mixtures explosion tests were performed in a constant volume 0.02 m3 spherical vessel. Five pressure-time curves were recorded. The effects of initial temperature on burning velocity were investigated for Lycopodium Clavatum-methane-air hybrid mixtures. The most important results from evaluated experiments are the values of burning rates to understand better the fundamental flame methane-air process in hybrid mixtures. The burning velocity is known to be altered by turbulence. It depends on the coupling interaction between the explosion pressure, the rate of pressure rise, the volume of the vessel, and the ignition source. When discussing hybrid mixtures, the focus is on an admixture of flammable gas in concentrations below the lower explosive limit of the gas itself. If this limit for the gas is exceeded, one soon has a situation where the worst-case scenario for a primary explosion would be a pure gas explosion. In the present study, we highlight the first evaluation of laminar burning velocity determined with electrical point ignition at higher initial temperatures. The experiments have been performed in a 0.02 m3 constant volume vessel of spherical shape adopted for the hybrid mixture experiments. The laboratory-size vessels used in the presented study are geometrically similar, have different sizes, and with point ignition. The values of burning velocity varied when the temperature is higher than 25 -C, and the cube-root law was affected. The initial temperature rise does not affect the dependence between the maximum rate of pressure rise and the maximum explosion pressure in the Cube-root law formula.

The sustainability of the indoor environment of buildings is also related to the conditions that arise in the case of fires. Fires in buildings are characterized by the formation of combustion products, which can significantly endanger the life and health of people. One of the major sources of danger is smoke. If there is no smoke exhaust into the outside environment during the development of the fire, the building is gradually filled with smoke. The important characteristic of the smoke layer is the level of the smoke layer, which changes over time. Several methods have been derived for determining the descent of the smoke layer in an enclosed area of space, which mainly differ in terms of the application area and limits of use. The methods used in the Czech Republic for the assessment of smoke layer descent in the case of fires do not have a clear rationale and in many cases lead to completely misleading results. For this reason, in connection with the standards for the assessment of the buildings in the Czech Republic, a new calculation technique (CSN) has been derived, which has been compared with the selected simple calculation techniques in large buildings. The deviations between the results have been evaluated by the percentage bias method (PBIAS), while the largest deviation, compared to the ISO standard technique, did not exceed 20%. The CSN calculation technique shows a favourable compliance with the technique presented by the ISO standard, where the deviation did not exceed 1.6%. In response to the proposed standards in the Czech Republic, the CSN calculation technique enables the assessment of safe evacuation in relation to the smoke layer interface and can be a considered perspective.

Our planet is warming due to climate change. Along with this, the incidence of fires is increasing. Fires negatively affect the environment. Fire prevention is one of the safety priorities in the Czech Republic and in the world. One aspect of safety is the evacuation of people, animals and potentially property. The paper will present a case study of escape route ventilation.