NATURAL VENTILATION SYSTEM The Complete Solution - Gilberts ...

Airflow DiagramsIntake or Exhaust TurretTypes 1, 2, & 3 Wind Driven Terminals Types 4 & 5Exhaust onleeward sideWindpressureNatural flow ofair to and frombuildingdepending ondesignrequirementsand temperaturedifferentialsSizing And Selection ChartsThe following data has been obtained from actualtests of penthouse turret assemblies.Graphs A & B represent pressure drops associatedwith various volume flow rates as taken from a1 cubic metre area penthouse.With four sides this equates to an active louvre facearea of 4 sq metres.In order to establish the air flow rate that would givethe same pressure drop through a 1 sq metre facearea louvre therefore the volumes given would bedivided by a factor of 4.Two different weather louvre designs are available.The Type NVT/1 is our standard single bank designand the Type NVT/2 is a single bank design withadditional rear eliminator channels. Whilst both of thedesigns meet class A specification the Type NVT/2offers the extra degree of weather ingress protectionthat may be required for certain projects.Pressure Drop Volume GraphsBlades at 45°Blades at 45° with eliminator1 1000987652 3 4 5 6 7 8 9 1Volume L/S2 3 4 5 6 7 8 9 11987651 100098765Volume L/S per Sq m2 3 4 5 6 7 8 9 12 3 4 5 6 7 8 9 1198765444433332222Pressure (Pa)10098765432198765432Pressure (Pa)10098765432198765432109876519876510987651987654444333322221100 2 3 4 5 6 7 8 9 100012 3 4 5 6 7 8 9 11100 2 3 4 5 6 7 8 9 100012 3 4 5 6 7 8 9 1Graph AGraph B25