How to Buy the Best Air Curtain in India

(From an Engineer’s Point of View)

An air curtain is not a cosmetic appliance. It is a mechanical air barrier system. If it fails on calculations, no brand name can save it.

Below is how an engineer thinks 👇

1️⃣ Door Geometry Comes First (Non-Negotiable)

✔ Door Width

Air curtain length must be ≥ door width
Never undersize thinking “air will spread” — it won’t.
Typical standard sizes:
- 900 mm (3 ft)
- 1200–1500 mm (4–5 ft)
- 1800–2100 mm (6–7 ft)

👉 If the opening is wider than standard sizes, modular or custom lengths are required.

✔ Door Height

This decides air velocity and motor power.

Door Height	Engineering Requirement
≤ 7 ft	Medium velocity
8–10 ft	High velocity
>10 ft	Industrial / twin motor

If height is ignored, air will never reach the floor, making the curtain useless.

2️⃣ Air Velocity & Air Throw (Most Important Parameter)

Forget fancy terms — focus on air reaching the floor with force.

Engineer’s Rule of Thumb:

Air velocity at outlet should be high enough so that velocity at floor ≥ 2–3 m/s
Typical outlet velocity range:
- Commercial: ~9–12 m/s
- Industrial: 15 m/s or higher

Ask this question before buying:

“At what height does this air curtain still maintain effective airflow?”

If seller can’t answer → walk away.

3️⃣ CFM / Air Volume (Barrier Strength)

Velocity without volume = weak barrier.

Low CFM → air bends easily → dust & insects enter
Adequate CFM → strong vertical air wall

For Indian conditions (dust, humidity, traffic):

Shops & offices: medium CFM
Kitchens, factories, warehouses: high CFM mandatory

4️⃣ Motor Engineering (Where Cheap Units Fail)

What an engineer checks:

Copper winding motor (not aluminium)
Continuous duty rating (8–12 hrs/day minimum)
Thermal protection

Why this matters in India:

High ambient temperature
Voltage fluctuations
Long operating hours

Cheap motors:
❌ Overheat
❌ Lose RPM
❌ Air velocity drops in 6–12 months

5️⃣ Blower Design (Hidden but Critical)

Centrifugal blower preferred over axial fans
Balanced impeller = less vibration + stable airflow
Multiple blowers are better for long lengths

If airflow is uneven across length → curtain fails at edges.

6️⃣ Body Material & Structural Strength

India = dust + humidity + heat.

Preferred:

Powder-coated metal or aluminium body
Rust-resistant fasteners
Proper internal motor mounting (not sheet-metal hanging)

Avoid:

❌ Thin plastic bodies for commercial use
❌ Decorative designs with weak airflow

Air curtain is a machine, not a showpiece.

7️⃣ Noise vs Performance (Realistic Expectation)

Low noise + high airflow = engineering trade-off

Offices / hospitals: lower noise acceptable
Shops / kitchens / factories: performance > silence

If someone promises:

“Very silent + very powerful”

Be skeptical.

8️⃣ Controls & Automation (Efficiency Layer)

Not mandatory, but useful:

Door sensor activation
Multiple speed settings
Auto ON/OFF

From engineering POV:

Reduces motor wear
Saves power
Improves lifespan

But remember:
👉 Automation cannot compensate for weak airflow

9️⃣ Electrical Compatibility (Often Ignored)

Single phase 230V is common
Check:
- Starting current
- Power consumption
- Proper earthing provision

Poor electrical design = motor failure, humming, overheating.

🔟 Application-Based Engineering Selection

Retail Shop

Medium velocity
Moderate CFM
Low–medium noise

Restaurant / Kitchen

High velocity
High CFM
Metal body compulsory

Warehouse / Industrial Gate

Very high velocity
Twin motor or industrial duty
Noise irrelevant, airflow critical

Cold Room / AC Retention

Focus on air seal strength
Continuous operation rating important

Engineer’s Final Checklist ✅

Before buying, confirm in writing:
✔ Door width & height compatibility
✔ Outlet air velocity
✔ Effective air throw till floor
✔ Motor winding type
✔ Body material
✔ Duty cycle rating
✔ Warranty on motor

If 2–3 answers are vague → reject the product.

Engineer’s Bottom Line

An air curtain should stop air, not just blow air.

If you want, tell me:

Door width
Door height
Application (shop / factory / kitchen / warehouse)

I’ll tell you exact technical specs you should demand, no brand names, no sales talk.

Blog

Here’s a clean, brand-neutral, engineer-level guide — no company names, no marketing fluff, only how an engineer actually evaluates an air curtain in India.