CFM is the cubic feet per minute of an air curtain. It measures the amount of air the curtain blows each minute and shows its airflow capacity. The higher CFM is better for blocking dust, insects, odours, and outside air.
When you enter a supermarket, mall, office, mosque, or cold storage, you may feel a blast of air from above the door. That is an air curtain, designed to keep indoor air comfortable and block dust, insects, and odors. One of the most important factors in choosing an air curtain is its CFM. Many people ask: What is CFM in an air curtain, and why is it important? In this article, I will explain CFM in a simple way, what it means, why it matters, how it is calculated, and how to select the right CFM for different uses.
What is CFM in an Air Curtain?
CFM stands for Cubic Feet per Minute. It measures the volume of air an air curtain blows each minute, or simply, how much air it pushes across a doorway.
For example:
When you find the best CFM for an air curtain, it depends on the door height, width, and type. In general:
- Small shops, offices & Homes: (7–9 ft doors): 700 – 1200 CFM
- Restaurants & cafés (9–10 ft doors): 1200 – 2000 CFM
- Supermarkets & malls (10–12 ft doors): 2000 – 3000 CFM
- Cold storage & warehouses (12–15+ ft doors): 3000 – 5000+ CFM
As a rule of thumb, taller doors need higher CFM to maintain an effective air barrier. For most commercial spaces, 800–1500 CFM is enough, while industrial doors require much higher airflow.
Why CFM is Important in Air Curtains
An Air Curtain performance ID depends on the CFM. These are the most important parts of the Air curtain. Higher CFM can create a strong Air barrier.
- Barrier Strength: Higher CFM makes the air curtain strong enough to block outside air at the doorway.
- Insect Control: Strong airflow prevents flies and mosquitoes from entering.
- Temperature Control: Can keep cool air inside in summer and warm air in winter.
- Dust & Pollution Prevention: It can block dust, smoke, and outdoor pollutants.
- Energy Savings: The best CFM can reduce HVAC workload and lower electricity bills.
The higher CFM ensures that the air curtain works effectively and efficiently. When you buy an air curtain, you have to first confirm the Air curtain CFM.
How is CFM Measured in Air Curtains?
CFM is calculated using this formula:
CFM=Air Velocity (FPM)×Air Outlet Area (sq. ft.)
Where:
- Air Velocity (FPM) = Speed of air in feet per minute.
- Air Outlet Area = Width × Height of the air curtain’s outlet.
Example:
If an air curtain has an air velocity of 2000 FPM and an outlet area of 2 sq. ft., then:
CFM=2000×2=4000 CFM
This calculation helps engineers and buyers select the right air curtain model for their space.
Ideal CFM Range for Different Applications
| Application | Door Height | Recommended CFM | Purpose |
| Small Shops & Offices | 7–8 ft | 700 – 1200 | Prevents dust & keeps indoor cooling |
| Restaurants & Cafes | 8–10 ft | 1200 – 2000 | Blocks insects & odors |
| Supermarkets & Malls | 10–12 ft | 2000 – 3000 | Maintains temperature & hygiene |
| Cold Storage / Industrial | 12–15+ ft | 3000 – 5000+ | Energy efficiency & contamination control |
Key Features of Air Curtains with High CFM
- High-Velocity Blowers: Provide strong airflow for larger doors.
- Adjustable Air Speed: Set your Airflow as needed.
- Low Noise Operation: The Original Air Curtain runs quietly even at high CFM.
- Energy-Efficient Motors: Deliver powerful airflow without using too much electricity.
- Durable Housing: Made for long-lasting use.
Benefits of the Right CFM in Air Curtains
✅ Better Comfort: It can keep a stable indoor temperature.
✅ Cleaner Environment: It can block dust, smoke, and germs.
✅ Insect Free: It can protect against flies and mosquitoes outdoors.
✅ Energy Savings: It reduces AC workload.
✅ Regulatory Compliance: It is essential for industries.
Common Mistakes When Choosing Air Curtain CFM
- Low CFM for high Doors : For a weak Air barrier, dust and insects easily come into the inside.
- Too High CFM for Small Spaces : Waste your energy and creates unnecessary noise.
- Ignoring Door Width : Wide doors may need multiple units.
- Overlooking Climate : Hot and humid areas need higher CFM.
Air Curtain CFM vs. AC Airflow
Air Curtains: Block air at entrances; measured in CFM per unit width.
Air Conditioners: Cool or heat rooms; measured in CFM per ton of cooling (400 CFM/ton).
Both use CFM, but their purposes are different. Air curtains block air at doors, while ACs condition the room air.
How to Choose the Right CFM for Your Air Curtain
- Measure Door Size : Taller or wider doors need higher CFM.
- Check the Application : Restaurants, shops, and cold storage have different airflow needs.
- Consider Noise : High CFM units can be louder; choose quieter models if needed.
- Look for Energy Efficiency : Prefer air curtains with inverter or BLDC motors.
- Get Expert Advice: Consult an HVAC technician to select the right CFM for your space.
FAQs – People Also Ask
What is the ideal CFM for an air curtain in a restaurant?
For restaurants, it needs 1200–2000 CFM to block insects and odors and maintain indoor cooling.
How is CFM different from FPM in air curtains?
CFM measures the total air volume per minute, while FPM (feet per minute) measures air speed.
Can a higher CFM save energy?
Yes. Higher CFM prevents air loss, reducing HVAC load and energy bills.
Does CFM affect noise?
Usually, higher CFM is louder, but modern air curtains use low-noise motors to keep their operation quiet.
Now, you need to understand what CFM is in an air curtain and why it is important. CFM affects airflow strength, barrier efficiency, energy savings, and overall performance.
Whether you have a small shop, restaurant, supermarket, or industrial cold storage, choosing the right CFM is essential to ensure maximum protection, cleanliness, and cost savings.
If you plan to install or upgrade an air curtain in Bangladesh or another humid climate, consult an HVAC expert to get the correct CFM for your space.
If you want to buy or install an air curtain in Bangladesh or another humid climate area, then you need to consult an HVAC expert to ensure accurate CFM.
AIRCONcare is an expert in ensuring your CFM. We are the largest dealer, distributor, importer, supplier, and agent of the best-quality air curtain in Bangladesh.