Toolnoza

HVAC & Ventilation

Size air ducts and estimate room air changes and kitchen hood airflow.

Engineering Tools

Duct Size CalculatorSize round and rectangular air ducts from airflow and target velocity, with CFM or m³/h inputs.Kitchen Hood CFM CalculatorEstimate residential wall or island kitchen hood airflow in CFM and m³/h using HVI width-based guidance.Fan Law CalculatorCalculate airflow, pressure and shaft power after a fan speed change.Air Changes per Hour CalculatorCalculate air changes per hour from airflow in CFM and room dimensions in feet.

Practical guides: HVAC & Ventilation

How to Calculate VFD Energy Savings: Formula & ExampleEstimate centrifugal fan or pump electricity savings using speed ratio, drive efficiency, operating hours and tariff.Duct Size Calculation: Convert CFM or m³/h to Duct DimensionsSize a round or rectangular air duct from airflow and target velocity. Follow CFM conversions, a worked example and practical sizing limits.