Specific Fire Load
Calculate the specific fire load of a space, q = (mass × LHV) ÷ area, dividing the total energy of the combustible materials (mass × lower heating value) by the floor area. The result, in MJ/m², is the heat that would be released per unit area if all the material burned — the parameter that classifies a building's fire risk and sets protection requirements (fire resistance, exits, sprinklers) in fire codes. The higher the fire load, the more severe the potential fire. Enter the fuel mass, the heating value and the area.
Result
—
Carga de incêndio específica
A carga de incêndio é a medida fundamental do combustível disponível num ambiente — quanto calor seria liberado se tudo o que pode queimar (móveis, papel, revestimentos, mercadorias) realmente queimasse. A versão específica normaliza isso pela área do piso: q = (massa × PCI) ÷ área, somando a energia de cada material (sua massa vezes o poder calorífico inferior, em MJ/kg) e dividindo pela área, resultando em MJ/m². Esse número é a base da classificação de risco nas normas e instruções técnicas dos corpos de bombeiros: ambientes com carga de incêndio baixa (escritórios, ~300–700 MJ/m²) exigem menos que depósitos de alta carga (arquivos, estoques de plásticos ou papel, que passam de 2.000 MJ/m²). Da carga de incêndio derivam exigências concretas: o tempo requerido de resistência ao fogo (TRRF) das estruturas, a necessidade de chuveiros automáticos, o número e a largura de saídas, e a compartimentação. Na prática usa-se a carga de incêndio específica característica tabelada por tipo de ocupação (já em MJ/m²), mas o cálculo direto a partir dos materiais é o que fundamenta esses valores. Quanto maior a carga, mais severo e duradouro o incêndio potencial — e mais robusta precisa ser a proteção. Informe a massa de combustível, o poder calorífico e a área.
Related Tools
Boiler Efficiency
Calculate the thermal efficiency of a boiler by the direct method, η = (m_steam × Δh) ÷ (m_fuel × LHV) × 100%, comparing the useful heat absorbed by the water/steam (steam flow × enthalpy gain) with the energy released by burning the fuel (fuel flow × lower heating value). The result, in %, shows how much fuel energy actually reached the steam; the rest is lost in flue gases, blowdown, radiation and unburnt fuel. Well-run industrial boilers reach 80–90%. Enter the steam flow, enthalpy gain, fuel flow and LHV.
Pile Allowable Load
Calculate a pile's allowable (working) load, Q_adm = Q_ult ÷ FS, from the ultimate bearing capacity Q_ult (kN) and the global safety factor FS. The allowable load is the maximum load that can be applied to the pile in service with adequate safety — obtained by dividing the ultimate capacity (the load that would cause FAILURE of the pile-soil system) by a safety factor covering uncertainties. The pile-foundation safety factor is typically HIGH (FS = 2.0-2.5 for ultimate capacity, higher if based only on theoretical formulas without a load test), reflecting the great uncertainty in determining soil capacity (unseen, heterogeneous and poorly known) and the severity of a foundation failure (which can collapse the whole structure). Codes often require different partial factors for tip and friction (which have different uncertainties), or limit-state methods. The allowable load sets how many piles are needed for the column loads: number of piles = column load ÷ allowable load. Load tests (measuring real field capacity) allow reducing the safety factor and optimizing design. Enter the ultimate capacity and the safety factor.
Smoke Plume Mass Flow
Calculate the mass flow of a fire's smoke plume by the Heskestad correlation, ṁ = 0.071·Q̇_c^(1/3)·z^(5/3), from the convective part of the heat release rate Q̇_c (kW) and the height above the fire base z (m). The result, in kg/s, is the amount of hot gases and smoke rising and accumulating, governing the design of smoke control and exhaust systems (mechanical or natural) that keep a smoke-free layer for safe evacuation. The flow grows strongly with height. Enter the convective heat fraction and the height.
The results provided by this tool are for general informational and educational purposes only and do not constitute professional, financial, medical, legal, tax or accounting advice. Always confirm important decisions with a qualified professional and official sources.