NATURAL VENTILATION SYSTEM The Complete Solution - Gilberts ...

Penthouse LouvrePerformance DataThe following tabulated table provides comprehensivesizing data for all of our standard size penthouseturret louvre range.Figures in the table are based upon air volumeand duct velocity variables and these can easilybe changed within a selection program to givenew data on alternative sizes where required.UnitEliminatorNom Size(internalduct size)Nominal Height(Blades x 75)TheoreticalBlade StandardModifiedBladeRequirement Blade Qty’s QtyOverBlade SizeStructuralOpening(on plan)FreeArea ofDuctGeometricFree AreathroughLouvreVolume at1m/sthroughDuct (l/s)ActiveFace Areaof Louvre(m 2 )l/s/m 2 ofLouvre(FaceVelocity)VNT/1VNT/2NNNNNNYYYYYY40060080010001200140040060080010001200140022530037552560067522530037552567575034578934578934578934578103457893457910765965116513651565176576596511651365156517655327329321132133215325327329321132133215320.160.360.641.001.441.960.160.360.641.001.441.960.190.390.641.141.562.050.190.390.641.141.762.281603606401000144019601603606401000144019600.571.031.602.613.484.470.571.031.602.613.854.91279350400384414438279350400384374400LEGEND:Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Standard order codeEliminator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Two Alternatives, recommend Type 1 for wind catchers and Type 2 for stacks for water ingress reasonsNominal Size (internal duct size) . . . . . . . . . . . . . .This will be the list size, the internal dimensions of the stackNominal Height (blades x 75+320) . . . . . . . . . . . . .The total height of the unit including lid and plinth from the top surface of a flat roofTheoretical Blade Requirement . . . . . . . . . . . . . . .This is the quantity of blades required to get the louvre blade free area to equal or to the desired ratio over stack free areaStandard Blade Qty . . . . . . . . . . . . . . . . . . . . . . . .This is the quantity of blades proposed for the standard product, sized to give a coefficient of discharge above 0.5Proposed Blade Qty . . . . . . . . . . . . . . . . . . . . . . . .This is the quantity of blades used to calculate the Heights/Pressures/areas/coefficients of discharge.Over Blade Size . . . . . . . . . . . . . . . . . . . . . . . . . . .The overall size of the unitsStructural Opening (on plan) . . . . . . . . . . . . . . . . .The size of the opening required in the roof skinFree Area of Duct . . . . . . . . . . . . . . . . . . . . . . . . . .Stack internal width x internal length (footprint)Geometric Free Area through Louvre . . . . . . . . . . .The total free area path through the four faces of the unitVolume at 1m/s through Duct (l/s) . . . . . . . . . . . . .Volume flow rate through the louvre at 1m/s stack velocity (likely velocities may be 0.25 to 0.5Active Face Area of Louvre (m_) . . . . . . . . . . . . . .The active area of the unit, 4 x blade pack height x width between internal blade end supports (ifl/s/m 2 of Louvre . . . . . . . . . . . . . . . . . . . . . . . . . . .Volume passing through the louvre (at 1m/s) / Active face area -Relates to the pressure drop testsPressure Drop@ 1m/s . . . . . . . . . . . . . . . . . . . . . .Pressure drop on the Terminal unit with 1m/s coming out of the stackPressure Drop@ 'above' m/s . . . . . . . . . . . . . . . . .Pressure drop on the unit with the duct velocity setting in the square above the table (user settable)Pressure Drop@ 'above' l/s . . . . . . . . . . . . . . . . . .Pressure drop on the unit with the air volume setting in the square above the table (user settable)Terminal Coefficient of Discharge (or entry) . . . . . .Coefficient of discharge of a terminal unit -(open duct ~1, with terminal sized for 0.5 min, or 100% free area ratio min)Louvre Coefficient of Discharge . . . . . . . . . . . . . . .Coefficient of discharge of a single louvre unit weightWeight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Unit weight not including duct and skirtNominal Duct Length . . . . . . . . . . . . . . . . . . . . . . .Nominal length of duct for roof angles and thickness set in boxes above the tableTo use as a selection calculator please contact Gilberts Technical Department26