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Calculate air velocity in a duct using airflow and duct dimensions. Supports rectangular and round ducts by applying a shape factor to the cross-sectional area.

Estimate pressure drop in HVAC ductwork using airflow, duct length, hydraulic diameter, air density, and duct roughness factor based on the Darcy-Weisbach relationship.

Estimate duct friction loss using airflow, duct length, equivalent diameter, duct material, and fitting allowance. This calculator uses a practical HVAC approximation where friction loss increases with airflow and duct roughness, and decreases with larger duct diameter.

Estimate total external static pressure in a duct system using straight duct length, equivalent fitting length, airflow, and duct area. The calculation uses velocity pressure and a friction rate approach to approximate the pressure drop across the duct run.

Estimate total duct air leakage in CFM based on duct surface area, leakage rate, system pressure, and duct condition.

Estimate the weight of a rectangular sheet metal duct section using its dimensions, length, material thickness, and material density.

Estimate the installed cost of HVAC ductwork based on duct length, duct type, home accessibility, project complexity, and regional labor pricing.

Estimate the total cost to replace residential HVAC ductwork based on home size, duct layout complexity, duct material, accessibility, and local labor cost factor.

Estimate the cost of residential air duct cleaning based on home size, number of vents, HVAC systems, contamination level, and accessibility.

Estimate the total cost to insulate HVAC ductwork based on duct length, duct perimeter, insulation thickness, insulation material, and installation difficulty.

Estimate the recommended flexible duct diameter based on required airflow, target air velocity, equivalent duct length, and fitting count. The calculation first determines ideal diameter from airflow and velocity, then adds a sizing factor for longer runs and additional fittings to reflect practical installation conditions.

Estimate the required round duct diameter based on airflow, target air velocity, system type, and fitting complexity. This calculator uses the duct sizing relationship between airflow and velocity to compute an equivalent round duct diameter.

Estimate the required rectangular duct cross-sectional area from airflow and target velocity, then calculate one duct dimension when the other dimension is known.

Calculate the required square duct side length based on airflow, target air velocity, and an optional safety factor for duct sizing.

Calculate the equivalent round duct diameter from a rectangular duct using width and height. This helps estimate a round duct size that provides similar airflow characteristics to a square or rectangular duct transition.

Convert a round duct size and airflow target into an equivalent rectangular duct area and estimated rectangular dimensions based on a chosen aspect ratio and friction allowance.

Calculate the surface area of a rectangular or round duct section using duct length and dimensions. Useful for estimating insulation, cladding, or sheet metal coverage.

Calculate the surface area of a round duct section using duct diameter and length. This calculator estimates the lateral sheet metal area of a cylindrical round duct and can also account for a quantity of identical duct sections.

Estimate airflow in cubic feet per minute (CFM) for a round or rectangular duct using duct dimensions and air velocity.

Estimate airflow in cubic feet per minute for a round duct using duct diameter, air velocity, system type, and airflow condition. The calculation uses duct cross-sectional area times air velocity, with adjustment factors for typical HVAC system behavior.

Estimate the installed cost of HVAC ductwork based on total duct length, duct width, material, insulation level, and installation difficulty.

Calculate recommended round duct diameter based on airflow, target air velocity, duct material factor, and system layout factor. This helps estimate an appropriate duct size for HVAC airflow distribution.

Estimate the recommended round duct diameter based on airflow, target air velocity, friction loss factor, and system type. This calculator provides an approximate duct size for HVAC planning.

Estimate required HVAC duct size in square inches based on airflow, target air velocity, duct type, run length, and fitting complexity.

Estimate the required round duct diameter for an HVAC branch based on airflow, target air velocity, duct material, and system type. This calculator uses the airflow equation for round ducts and applies practical adjustment factors for friction and design conditions.

Estimate the recommended rectangular air duct cross-sectional area based on airflow, target air velocity, and system type, then convert that area into an equivalent round duct diameter for HVAC sizing.

Estimate recommended residential round duct diameter based on target airflow, friction rate, duct material, and total effective length. This simplified calculator helps size a main branch duct for typical home HVAC applications.

Estimate the required rectangular duct cross-sectional area for a commercial HVAC branch using airflow, target air velocity, friction loss factor, and system type. The result helps size ducts in square inches for preliminary design.

Estimate the recommended rectangular supply duct cross-sectional area based on airflow, target air velocity, system type, and duct material. This calculator helps size a main supply duct using standard HVAC airflow and velocity relationships.

Estimate the recommended return air duct size in square inches based on airflow, target return air velocity, number of return grilles, and a safety factor for system resistance and layout.