Observed arrival · 2026-09-01
CfmDuct Counts the Pressure, Not Just the Inches
A focused HVAC reference and calculation site for sizing ducts by room airflow, friction rate, static pressure, fittings, and project cost.
Field notes
The site organizes its material around the airflow and pressure problems that determine whether a duct system performs well, rather than treating diameter as the only variable. Its visible inventory includes 1,494 city-level cost calculations, 153 state-level entries, and 40 flex-versus-rigid comparisons covering airflow, material, and compression conditions. The homepage also links to practical explainers on measuring static pressure, diagnosing a persistently hot room, and checking whether return air is undersized.
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Editorial observations of this landing page, not a rating.
One card from the complete issue