Category Archives: HVAC


Calculate Fresh Air exchanges flow in Room according the air change rate per hour.

Duct Size Calculator

Temperature:  [°C] Flow rate: [m3/hr] Duct Size: Select Pipe Type: Circle PipeRectangular Pipe Internal Diameter: [mm] Width: [mm] Roughness height: [mm] Pipe Lenght: [m] Equivalent diameter: [mm] Flow Area: [m2] Flow Viscosity: [Kg/m.s] Flow Velocity: [m/s] Flow Density: [Kg/m3] Reynolds Number: Friction Factor: Velocity Pressure: Pa Pressure drop: Pa/m Total pressure drop on Pipe: Pa

Air Conditionner

To calculate the size, simply multiply the length with the width of the room or area to be cooled. Then, as a practical number that total multiplied by 600 BTU.