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Calculation methods
83 methods across 9 documents
BR 187
Ventilation factor
BR 187 | Ch. 1 | Eq. 1
Calculates the Ventilation Factor
Transfer of Heat by Thermal Radiation
BR 187 | Appendix A - View Factors
Calculates the Incident Heat Flux on a receiving surface using pre defined configurations. center aligned can be used when the point of reference is in the center of the emitting surface. Corner aligned when the point of reference is in the corner of the emitting surface. When neither work perfectly, we can split the emitting surfaces into smaller parts and apply the appropriate alignment to each part. Adding and subtracting appropriately.
BS 9999
Merging flow from stair with storey exit at final exit level
BS 9999 | Ch. 15 | Fig. 6a
Calculates the merging flow for stairs where the stair and storey exit share a common final exit
Merging flow from stair above and from stair below final exit level
BS 9999 | Ch. 15 | Fig. 6b
Calcualtes the merging flow from stairs above and below the final exit level
Merging flow from stairs from above and below, combined with storey exit
BS 9999 | Ch. 15 | Fig. 6c
Calcualtes the merging flow from stairs above and below the final exit level, combined with with storey exit
CIBSE Guide E
Heat Release Rate required for flashover
CIBSE Guide E | Ch. 6 | Eq. 6.7
Heat Release Rate required for flashover. Most simple expression from SFPE Handbook
Mean flame height of luminous flames
CIBSE Guide E | Ch. 6 | Eq. 6.55
Mean flame height of fires away from walls
Height of the flame above the top of the opening
CIBSE Guide E | Ch. 6 | Eq. 6.57
Height of the flame projection above the top of the opening
Ventilation-controlled rate of burning
CIBSE Guide E | Ch. 6 | Eq. 6.58
Ventilation-controlled rate of burning for cellulosic fires
Dimensions of a room or compartment (simple case)
CIBSE Guide E | Ch. 6 | Appendix - Simple case
Relevant compartment dimensions for the simple case, which is a compartment with a single opening. These dimensions are then used in empirical correlations to predict fire dynamics
Relevant compartment dimensions for more than one window
CIBSE Guide E | Ch. 6 | Appendix - More than one window
Relevant compartment dimensions for more than one window case. Users can define multiple individual openings, and the runner calculates equivalent dimensions.
Capacity of a stair for simultaneous evacuation
CIBSE Guide E | Ch. 7 | Eq. 7.2
Capacity of a stair for simulataneous evacuation, subject to minimum stair widths
Required width of the stair
CIBSE Guide E | Ch. 7 | Eq. 7.3
Required width of the stair for simultaneous evacuation
Maximum flow rate of persons through a doorway
CIBSE Guide E | Ch. 7 | Eq. 7.6
Maximum flow rate of persons through a doorway or level corridor
Maximum number of people that can be accommodated within a stairway
CIBSE Guide E | Ch. 7 | Eq. 7.7
Maximum number of people that can me accomodated within a stairway at any one time
Exit capacity of a stairway
CIBSE Guide E | Ch. 7 | Eq. 7.8
Maximum number of people able to enter the stair within a specified period without suffering extreme discomfort
Acceptance capacity of a stair
CIBSE Guide E | Ch. 7 | Eq. 7.9
Maximum number of people able to enter the stair within a specified period given a certain occupant density in the stairs and landing
Maximum volumetric flow rate
CIBSE Guide E | Ch. 10 | Eq. 10.1
Calculates the maximum volumetric flow rate, without plug-holing, by a single exhaust vent
Minimum separation distance between exhaust vents
CIBSE Guide E | Ch. 10 | Eq. 10.2
Calculates the miminmum separation distance between exhaust vents to prevent plug-holing
Volumetric flow rate from mass flow rate (smoke exhaust)
CIBSE Guide E | Ch. 10 | Eq. 10.3
Calculates the volumetric flow rate for a smoke exhaust if the mass flow rate is known and, considering temperature dependence of density
Time to burning of skin due to radiant heat
CIBSE Guide E | Ch. 10 | Eq. 10.4
Calculates the time to burning of skin due to radiant heat for heat fluxes above 1.7 kW/m2
Distance at which an object can be perceived in smoke
CIBSE Guide E | Ch. 10 | Eq. 10.7
Calculates the visibility in smoke as a function optical density and a visibility coefficient
Calculates the Fractional Effective Dose (FED)
CIBSE Guide E | Ch. 10 | Eq. 10.8
Calculates the fractional effective dose
Limiting average air velocity for opposed air flow | Room of fire origin to large volume
CIBSE Guide E | Ch. 10 | Eq. 10.10
Limiting average air velocity where opposed air flow is used to stop smoke spread from room of origin to a large volume
Limiting average air velocity for opposed air flow | Fire in large volume to adjoining room
CIBSE Guide E | Ch. 10 | Eq. 10.11
Limiting average air velocity where opposed air flow is used to stop smoke spread from large space to adjoining small space below the smoke layer interface
Limiting average air velocity for opposed air flow | Room of fire origin to corridor
CIBSE Guide E | Ch. 10 | Eq. 10.12
Limiting average air velocity where opposed air flow is used to stop smoke spread from an adjoining room into a corridor
Fire Dynamics Tools
Hot Gas Temperature Increase (MQH Method)
Fire Dynamics Tools | Ch. 2 | Eq. 2.1
Calculates the hot gas temperature increase for naturally ventilated enclosures using the MQH correlation.
Compartment Interior Surface Area
Fire Dynamics Tools | Ch. 2 | Eq. 2.2
Calculates the total interior surface area of a compartment excluding ventilation openings
Heat Transfer Coefficient (Long Times or Thin Walls)
Fire Dynamics Tools | Ch. 2 | Eq. 2.3
Calculates the heat transfer coefficient for long exposure times or thin walls
Thermal Penetration Time
Fire Dynamics Tools | Ch. 2 | Eq. 2.4
Calculates the thermal penetration time for a wall boundary
Heat Transfer Coefficient (Short Times or Thick Walls)
Fire Dynamics Tools | Ch. 2 | Eq. 2.5
Calculates the heat transfer coefficient for short exposure times or thick walls
Hot Gas Temperature Increase (Beyler Method)
Fire Dynamics Tools | Ch. 2 | Eq. 2.6
Calculates the hot gas temperature increase using the Beyler method for forced ventilation
Nondimensional Hot Gas Temperature Increase
Fire Dynamics Tools | Ch. 2 | Eq. 2.7
Calculates the nondimensional hot gas temperature increase for naturally ventilated enclosures
Hot Gas Temperature Increase (Steady State)
Fire Dynamics Tools | Ch. 2 | Eq. 2.8
Calculates the steady state hot gas temperature increase for forced ventilation
Convective Heat Transfer Coefficient
Fire Dynamics Tools | Ch. 2 | Eq. 2.9
Calculates the convective heat transfer coefficient considering both short and long time behaviour
Height of Smoke Layer Interface (Natural Ventilation)
Fire Dynamics Tools | Ch. 2 | Eq. 2.10
Calculates the height of the smoke layer interface above the fire for natural ventilation
Entrainment Constant for Smoke Layer Height
Fire Dynamics Tools | Ch. 2 | Eq. 2.11
Calculates the entrainment constant k for use in smoke layer height calculations
Entrainment Constant for Smoke Layer Height (Simplified)
Fire Dynamics Tools | Ch. 2 | Eq. 2.12
Calculates the simplified entrainment constant k for use in smoke layer height calculations
Density of Hot Gas Layer
Fire Dynamics Tools | Ch. 2 | Eq. 2.13
Calculates the density of the hot gas layer from the gas temperature
Wall Fire Flame Height
Fire Dynamics Tools | Ch. 4 | Eq. 4.1
Calculates the flame height for a fire against a wall
Line Fire Flame Height
Fire Dynamics Tools | Ch. 4 | Eq. 4.2
Calculates the flame height for a line fire
Corner Fire Flame Height
Fire Dynamics Tools | Ch. 4 | Eq. 4.3
Calculates the flame height for a fire in a corner
Thermal Radiation from Point Source
Fire Dynamics Tools | Ch. 5 | Eq. 5.1
Calculates the thermal radiation from a point source fire
Maximum Centerline Temperature Rise in Plume
Fire Dynamics Tools | Ch. 9 | Eq. 9.2
Calculates the maximum centerline temperature rise in a fire plume
Virtual Origin over Diameter
Fire Dynamics Tools | Ch. 9 | Eq. 9.3
Calculates the virtual origin to diameter ratio for a fire plume
Effective Diameter
Fire Dynamics Tools | Ch. 9 | Eq. 9.4
Calculates the effective diameter of a non-circular fire source
Visibility Through Smoke
Fire Dynamics Tools | Ch. 18 | Eq. 18.1
Calculates the visibility through smoke
Concentration of Particulates
Fire Dynamics Tools | Ch. 18 | Eq. 18.2
Calculates the concentration of particulates in a compartment
Mass of Particulates Produced
Fire Dynamics Tools | Ch. 18 | Eq. 18.3
Calculates the mass of particulates produced from burning
Introduction to Fire Dynamics
Burning regime
Introduction to Fire Dynamics | Ch. 10 | Eq. 10.18
Determines the burning regime in a compartment fire with wood or wood-based fuels.
Time to Ignition (Thermally Thick Solids)
Introduction to Fire Dynamics | Ch. 6 | Eq. 6.32
Calculates the time to ignition for thermally thick solids using Drysdale's equation 6.32.
Time to Ignition (Thermally Thin Solids)
Introduction to Fire Dynamics | Ch. 6 | Eq. 6.33
Calculates the time to ignition for a thermally thin solid assuming a constant external heat flux and ignoring heat losses
PD 7974-1
Maximum enclosure temperature
PD 7974-1 | Eq. 41, 42, 43 & 44
Calculates the maximum enclosure temperature after flashover
HRR at flashover
PD 7974-1 | Eq. 28 & 29
Calculates the HRR at flashover, comparing methods developed by Thomas and McCaffrey et al.,
Maximum HRR in a compartment fire
PD 7974-1 | Eq. 4 & 33
Calculates the maximum HRR for a compartment fire, comparing fuel-controlled and ventilation-controlled conditions
SFPE Handbook
HRR for heat detector response
SFPE Handbook | Ch. 14 | Eq. 14.2 & 14.3
Calculates the heat release at which a heat detector submerded in the ceiling jet will activate
Pressure difference due to stack effect
SFPE Handbook | Ch. 50 | Eq. 50.1
Calculates the pressure difference between indoor and outdoor environments due to stack effect
Pressure difference between fire compartment and surroundings
SFPE Handbook | Ch. 50 | Eq. 50.2
Calculates the pressure difference between a fire compartment and its surroundings
Wind pressure
SFPE Handbook | Ch. 50 | Eq. 50.4
Calculates the wind pressure on a building surface
Piston effect pressure difference
SFPE Handbook | Ch. 50 | Eq. 50.6
Upper limit for the piston effect for an elevator with enclosed lobbies
Effective area of elevator shaft
SFPE Handbook | Ch. 50 | Eq. 50.7
Calculates the effective leakage area for pressurization systems
Door opening force
SFPE Handbook | Ch. 50 | Eq. 50.14
Calculates the force required to open a door against a pressure difference
Height limit for pressurization
SFPE Handbook | Ch. 50 | Eq. 50.15
Calculates the maximum height for effective stairwell pressurization
Flow area factor
SFPE Handbook | Ch. 50 | Eq. 50.16
Calculates the flow area factor for pressurization system design
Stairwell temperature
SFPE Handbook | Ch. 50 | Eq. 50.17
Calculates the stairwell temperature based on outdoor and building temperatures when the pressurisation air is untreated
Visibility (by mass concentration)
SFPE Handbook | Ch. 50 | Eq. 50.19
Calculates visibility through smoke based on mass concentration
Visibility (by percent obscuration)
SFPE Handbook | Ch. 50 | Eq. 50.20
Calculates visibility through smoke based on percent obscuration
Pedestrian travel speed
SFPE Handbook | Ch. 59 | Eq. 59.5
Calculates pedestrian travel speed along a path based on population density
Specific flow
SFPE Handbook | Ch. 59 | Eq. 59.6
Calculates the specific flow of evacuating persons per unit time per unit effective width
Specific flow from density
SFPE Handbook | Ch. 59 | Eq. 59.7
Calculates specific flow directly from population density by combining Equations 59.5 and 59.6
Calculated flow
SFPE Handbook | Ch. 59 | Eq. 59.8
Calculates the flow rate of persons passing a point in an exit route
Calculated flow from density
SFPE Handbook | Ch. 59 | Eq. 59.9
Calculates flow rate directly from fundamental parameters by combining Equations 59.7 and 59.8
Time for passage
SFPE Handbook | Ch. 59 | Eq. 59.10
Calculates the time for a group of persons to pass a point in an exit route
Time for passage from density
SFPE Handbook | Ch. 59 | Eq. 59.11
Calculates time for passage directly from fundamental parameters by combining Equations 59.9 and 59.10
Specific flow at transition point
SFPE Handbook | Ch. 59 | Eq. 59.12
Calculates the specific flow departing from a transition point with one incoming flow
Specific flow at transition point with two inflows
SFPE Handbook | Ch. 59 | Eq. 59.13
Calculates the specific flow departing from a transition point with two incoming flows
Evacuation time (congestion dominates)
SFPE Handbook | Ch. 59 | Eq. 59.15
Calculates evacuation time when congestion dominates the results
Evacuation time (congestion does not dominate)
SFPE Handbook | Ch. 59 | Eq. 59.16
Calculates evacuation time when congestion does not dominate the results
TR 17
Miscellaneous
Travel time
Misc | Evacuation | Travel Time
Calculates travel time from distance and walking speed
Travel distance
Misc | Evacuation | Travel Distance
Calculates travel distance from walking speed and travel time
Walking speed
Misc | Evacuation | Walking Speed
Calculates walking speed from travel distance and travel time
Heat release rate from HRRPUA
Misc | Fire Dynamics | HRR from HRRPUA
Calculates the total heat release rate from the heat release rate per unit area and fire area