Hood Static Pressure Calculator
Total static for a hood exhaust system.
Enter your values
Enter the filter loss in in wc.
Enter the duct length in ft.
Enter the friction rate in in wc/100 ft.
Enter the fitting equivalent length in ft.
Enter the discharge loss in in wc.
Results update instantly as you type — no submit needed. Your values are remembered on this device, and the shareable link reopens the calculator with exactly these numbers.
- Total static pressure
- 1 in wc
- Duct portion
- 0.15 in wc
- Filter portion
- 0.6 in wc
- Select fan at
- 1.15 in wc
- In Pa
- 249
Quick answer
Hood system static pressure is the sum of filter loss, duct friction and discharge loss.
TSP = filter + duct + fitting + discharge losses
At a glance
| What it does | Total static for a hood exhaust system. |
|---|---|
| Category | HVAC & Airflow |
| Inputs needed | Filter loss, Duct length, Friction rate, Fitting equivalent length, Discharge loss |
| Main output | Total static pressure |
| Formula | TSP = filter + duct + fitting + discharge losses |
| Cost | Free — no sign-up, no download |
How to use the Hood Static Pressure Calculator
- 1Get the filter loss from the hood submittal at design airflow.
- 2Add duct friction from length plus fitting equivalent length.
- 3Select the fan at 10-15% above the calculated total.
Inputs explained
- Filter loss(in wc)
- Enter the filter loss in in wc.
- Duct length(ft)
- Enter the duct length in ft.
- Friction rate(in wc/100 ft)
- Enter the friction rate in in wc/100 ft.
- Fitting equivalent length(ft)
- Enter the fitting equivalent length in ft.
- Discharge loss(in wc)
- Enter the discharge loss in in wc.
Worked example
Using the values the calculator loads with:
Inputs
- Filter loss0.6 in wc
- Duct length40 ft
- Friction rate0.15 in wc/100 ft
- Fitting equivalent length60 ft
- Discharge loss0.25 in wc
Results
- Total static pressure1 in wc
- Duct portion0.15 in wc
- Filter portion0.6 in wc
- Select fan at1.15 in wc
- In Pa249
Frequently asked questions
Why add a margin?
Grease build-up raises resistance over time; the margin keeps capture velocity as the system loads.
Typical total?
Most commercial hood systems land between 1.0 and 1.75 in wc.
What do I need to enter into the Hood Static Pressure Calculator?
Just 5 values: filter loss, duct length, friction rate, fitting equivalent length, discharge loss. Every field starts with a realistic example, so you can change one number at a time and watch the result update instantly.
How does the Hood Static Pressure Calculator work out the answer?
Hood system static pressure is the sum of filter loss, duct friction and discharge loss. It applies the formula TSP = filter + duct + fitting + discharge losses and shows the working so you can check each step by hand.
Is the Hood Static Pressure Calculator free, and do I need an account?
It is completely free with no sign-up, no download and no usage limit. Everything is calculated in your browser, so the numbers you type never leave your device.
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.