Clearing cigar smoke takes two different tools: exhaust ventilation, which removes live smoke and brings in fresh air, and a carbon air purifier (a "smoke eater"), which strips the lingering smell. A home cigar room can usually get by with one strong purifier and a small exhaust fan. A lounge needs exhaust sized to code plus purifiers. This guide shows how to size both with real numbers.
Exhaust vs air purifier: two different jobs
| Exhaust / ventilation | Air purifier (smoke eater) | |
|---|---|---|
| What it does | Pulls smoky air out of the room and replaces it with fresh air | Cycles the room's air through carbon and HEPA filters |
| Best at | Removing smoke while people are smoking; keeping smoke out of the rest of the building | Removing lingering odor and haze between and after sessions |
| Weak at | Smell that has soaked into the room; heating and cooling costs go up | Keeping up with many smokers at once |
| Cost | Fan + ducting + install; plus makeup air in a commercial space | Unit + filters; no installation |
The two arguments you hear from smokers ("buy a big purifier" vs "purifiers don't work, you need ventilation") are both half right. Exhaust handles the live smoke; carbon handles the smell that's left. Use both and size each one properly.
The math: air changes per hour (ACH)
Everything comes down to how many times an hour the room's air is replaced (exhaust) or cleaned (purifier).
- Room volume = length × width × ceiling height (cubic feet)
- Air changes per hour = airflow (CFM) × 60 ÷ room volume
- Airflow needed = room volume × target ACH ÷ 60
Two cautions. Real airflow through a deep carbon bed or long duct run is lower than a fan's maximum rating, and you won't run a purifier on high all the time. Size with a margin of at least 25%.
| Target | Purifier ACH | Notes |
|---|---|---|
| Occasional cigar in a den | 6+ | One unit is usually plenty |
| Dedicated home cigar room, regular smoking | 10+ | Add an exhaust fan for live smoke |
| Lounge or bar room | 8+ from purifiers | On top of code-required exhaust |
Setting up a home cigar room
Step 1: Seal and separate
Keep the door closed while smoking. Weatherstrip the door frame except for a controlled gap at the bottom. Smoke follows air pressure, so the goal is air moving into the cigar room from the house, never out.
Step 2: Add a small exhaust fan
Mount an exhaust fan in an outside wall or window, or duct an inline fan to outside. For a typical home cigar room, a quiet inline fan in the 100–300 CFM range creates slight negative pressure and removes live smoke. Make sure air can get in: a door undercut or a transfer grille lets house air replace what the fan removes. Without a path for replacement air, the fan moves far less than its rating.
Step 3: Add a carbon purifier for odor
Size it for 10+ ACH. A 12 × 12 ft den with an 8 ft ceiling holds 1,152 cubic feet; an Airpura T600 at its maximum 560 CFM cycles that air about 29 times an hour, so one unit is more than enough, and you can run it on a quiet setting. Read the best air purifier for cigar smoke for why carbon weight matters more than HEPA.
Step 4: Choose hard surfaces
Leather, wood, tile and blinds hold far less smell than carpet, curtains and fabric sofas. If you're building a room from scratch, this is the cheapest odor control there is.
Garages, basements and man caves
These spaces are often large and open to the rest of the house through a stairwell or a shared HVAC return, which pulls smoke everywhere. Two fixes matter most: close or filter any return-air grille in the smoking area so the house's HVAC doesn't spread smoke, and use an exhaust fan to keep the space at slight negative pressure. Then size purifiers by volume; a 24 × 24 ft garage with 9 ft ceilings is 5,184 cubic feet, which one Airpura T700 cycles about 7 times an hour.
Ventilation for a cigar lounge
Commercial smoking rooms are regulated, and the rules vary by state and city. Many places allow indoor smoking only in licensed cigar bars or retail tobacco shops. What follows is general background to help you talk to your engineer, not a design.
- Outdoor air: the International Mechanical Code's ventilation table lists smoking lounges at 60 CFM of outdoor air per person, with a default occupant density of 70 people per 1,000 sq ft (IMC Section 403).
- No recirculation: the code requires mechanical exhaust from smoking lounges and prohibits recirculating their air to other spaces.
- Interpretations differ: ASHRAE 62.1, which most of the IMC table is based on, has never given a prescriptive rate for smoking lounges, so local officials interpret it (example: North Carolina's code interpretation for hookah lounges).
- Negative pressure: keep the lounge at lower pressure than retail areas, offices and especially your walk-in or display humidors, so smoke doesn't drift into stock.
Worked example: a 600 sq ft lounge
A 20 × 30 ft lounge with a 10 ft ceiling holds 6,000 cubic feet.
| Item | Calculation | Result |
|---|---|---|
| Outdoor air for 20 occupants | 20 × 60 CFM | 1,200 CFM |
| Outdoor air at code default density | 600 sq ft × 70/1,000 = 42 people × 60 | 2,520 CFM |
| Exhaust ACH at 1,200 CFM | 1,200 × 60 ÷ 6,000 | 12 ACH |
| Purifier ACH, two T700s | 2 × 635 × 60 ÷ 6,000 | about 12.7 ACH |
Your engineer will set the real design occupancy. The point is scale: lounge exhaust is measured in thousands of CFM, and bringing that much outdoor air in means heating and cooling it, which is why lounge HVAC is a serious line item. Purifiers don't replace that exhaust, but two or three units placed apart make the room smell far better between busy sessions and reduce the smell that drifts into the shop.
Choosing smoke eaters
| Model | Max airflow | Best for |
|---|---|---|
| Airpura T600 | 560 CFM | Home cigar rooms and dens |
| Airpura T600 DLX | 560 CFM | Daily smoking plus chemical odors (impregnated carbon) |
| Airpura T700 | 635 CFM | Larger rooms, garages and lounges |
The full comparison is in Airpura T600 vs T600 DLX vs T700, and every model is in our smoke eaters collection.
Placement and running tips
- Put purifiers where people smoke, out in the open, not in a corner behind furniture.
- In larger rooms, spread units out so air moves through the whole space.
- Place exhaust high and on the opposite side of the room from where fresh air enters, so air sweeps across the smokers.
- Run purifiers on low all the time and turn them up during and after smoking.
- Change the tar pre-filter often; it protects the expensive carbon.
Common mistakes
- Relying on HEPA-only purifiers. They clear haze but not smell.
- An exhaust fan with no replacement air. It can't move air it can't draw in.
- Sharing HVAC returns between the smoking room and the house or shop.
- Undersizing by trusting box ratings. "2,000 sq ft" ratings assume dust, not smoke.
- Building a lounge before talking to the building official. Code, licensing and ventilation drive the budget.
Frequently asked questions
Do smoke eaters actually work?
They remove a large share of odor and particles by cycling air through carbon, and they're very effective between and after sessions. They can't replace exhaust in a room where several people smoke at once.
How many CFM do I need for a cigar room?
Multiply room volume by your target air changes per hour and divide by 60. For odor control in a home room, aim for 10 or more ACH from a purifier; for a lounge, plan exhaust to code plus purifiers.
Do I need an exhaust fan if I have a purifier?
For occasional smoking in a closed den, a strong purifier may be enough. For a dedicated cigar room, add a small exhaust fan so smoke doesn't drift into the house.
One big unit or several smaller ones?
Several units placed apart clean a large room more evenly.
Can you size it for me?
Yes. Call (985) 531-8513 with your room dimensions and how many people smoke at once.
Code references are general information, not engineering or legal advice; requirements depend on your jurisdiction. Sources: International Mechanical Code Section 403 (via CUNY City Tech), NC Office of State Fire Marshal interpretation, Airpura specifications. Updated October 2026.
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