FieldengThermal & HVAC
Airflow from Velocity and Area
Q = v A for a grille, opening, or duct. Enter area, or width × height, or diameter — not both area and geometry.
Thermal & HVACFluid & Pressure
Q = v A for a grille, opening, or duct. Enter area, or width × height, or diameter — not both area and geometry.
App id: THERM-01. Reference version 1.0.
How to fill it
Fill the inputs. The tool shows the outputs.
On the tool screen, Calc is the working sheet. Presets stores values you reuse. Reference is the formula, assumptions, and provenance below.
Formula
Q = v AInputs
| Name | Unit |
|---|---|
| Air velocity (camera) | ft/min |
| Area (optional) | m2 |
| Width (optional) | in |
| Height (optional) | in |
| Diameter (optional) | in |
Outputs
| Name | Unit |
|---|---|
| Airflow (hero result) | ft3/min |
| Area | m2 |
Diagnose
Observations are context. They do not pass or fail a structure. See Diagnose.
| When | Observation | Severity |
|---|---|---|
Air velocity < 0.3 | Low velocity | info |
Air velocity > 5 | High velocity | caution |
Air velocity > 3 | Elevated velocity | info |
Assumptions
- No dump factor or area correction unless you fold it into the entered velocity or area.
Provenance
- Continuity. A single-point velocity is not a true average unless the traverse says so.