Airflow & Duct Sizing Calculators
Design, balance, and size residential and commercial HVAC air distribution systems using standard equal friction equations (ASHRAE/SMACNA/ACCA).
Digital Ductulator & Air Duct Sizing Tool
Professional online ductulator for HVAC engineers and technicians. Size round, rectangular, and flat oval ductwork using standard equal friction equations.
Flexible Duct CFM & Friction Drop Chart
Interactive flexible duct CFM capacity chart across standard diameters (4" to 20") with real-world installation sag and compression derating.
HVAC CFM & Airflow Calculator
Calculate HVAC airflow (CFM) using the sensible heat equation, duct velocity and area, room air changes per hour (ACH), or cooling tonnage rules.
Kitchen Range Hood CFM & Make-Up Air Sizer
Calculate required kitchen range hood CFM for gas and electric cooktops. Check mandatory IRC Section M1503.6 make-up air code requirements.
Duct Friction Loss & Total Equivalent Length (TEL) Sizer
Calculate ACCA Manual D Total Equivalent Length (TEL), Available Static Pressure (ASP), and Design Friction Rate (FR) for residential duct design.
MERV Air Filter Sizing & Static Pressure Drop Sizer
Calculate HVAC air filter face velocity (FPM) and static pressure drops across 1-inch, 2-inch, and 4-inch deep MERV 8 to MERV 16 pleated media.
Forced Air Distribution & Dynamic Static Pressure Path
Airflow circulation from return intakes through filtration, blower pressurization, trunk ducting, and room supply registers.