Smoking Room Ventilation Calculator
Exhaust airflow for a designated smoking room.
Enter your values
Enter the occupants you are working with.
Enter the floor area in sq ft.
Enter the ceiling height in ft.
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.
- Design exhaust
- 563 CFM
- Per-occupant basis
- 480 CFM
- 15 ACH basis
- 563 CFM
- Supply air (90%)
- 506 CFM
- Net negative
- 56 CFM
Quick answer
Smoking rooms are typically exhausted at 60 CFM per occupant and held negative to surrounding spaces.
CFM = 60 x occupants, minimum 15 ACH
At a glance
| What it does | Exhaust airflow for a designated smoking room. |
|---|---|
| Category | HVAC & Airflow |
| Inputs needed | Occupants, Floor area, Ceiling height |
| Main output | Design exhaust |
| Formula | CFM = 60 x occupants, minimum 15 ACH |
| Cost | Free — no sign-up, no download |
How to use the Smoking Room Ventilation Calculator
- 1Enter the room's occupancy and dimensions.
- 2Use whichever basis gives the higher airflow.
- 3Supply about 90% of the exhaust so the room stays negative and smoke cannot migrate.
Inputs explained
- Occupants
- Enter the occupants you are working with.
- Floor area(sq ft)
- Enter the floor area in sq ft.
- Ceiling height(ft)
- Enter the ceiling height in ft.
Worked example
Using the values the calculator loads with:
Inputs
- Occupants8
- Floor area250 sq ft
- Ceiling height9 ft
Results
- Design exhaust563 CFM
- Per-occupant basis480 CFM
- 15 ACH basis563 CFM
- Supply air (90%)506 CFM
- Net negative56 CFM
Frequently asked questions
Can air cleaners replace exhaust?
No — filtration removes particles but not the gases, so exhaust is still required.
Door treatment?
Self-closing doors and a vestibule dramatically reduce leakage.
What do I need to enter into the Smoking Room Ventilation Calculator?
Just 3 values: occupants, floor area, ceiling height. 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 Smoking Room Ventilation Calculator work out the answer?
Smoking rooms are typically exhausted at 60 CFM per occupant and held negative to surrounding spaces. It applies the formula CFM = 60 x occupants, minimum 15 ACH and shows the working so you can check each step by hand.
Is the Smoking Room Ventilation 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.