BOTANVÈWhat Size Air Curtain Do I Need?
Air curtains are sized primarily by doorway width: the unit must be as wide as, or wider than, the opening so the air stream covers the full width with no gap at the edges. Mounting height is the second constraint, because every unit has a maximum height at which its air stream still reaches the floor with enough velocity to form a seal.
Step 1 — width
| Clear opening width | Air curtain |
|---|---|
| Up to 0.6 m (service hatch, narrow door) | 0.6 m |
| 0.6–0.9 m | 0.9 m |
| 0.9–1.0 m | 1.0 m |
| 1.0–1.2 m | 1.2 m |
| 1.2–1.5 m | 1.5 m |
| 1.5–1.8 m | 1.8 m |
| 1.8–2.0 m | 2.0 m |
| Over 2.0 m | Two units side by side (e.g. 1.2 m + 1.2 m for 2.4 m) |
UAE-specific considerations
In the UAE climate, the primary function of an air curtain at a shop or office entrance is to stop hot, dusty, and sometimes humid outdoor air from entering the cooled interior. Secondary benefits include keeping insects out and containing conditioned air during peak summer months when outdoor temperatures regularly exceed 42°C. An undersized air curtain — for example a 1.2 m unit on a 1.5 m doorway — will not cover the full opening and will allow flanking air to enter at the edges.
Wind is a factor in ground-floor units facing main roads or open areas. Nanyoo cross-flow units manage moderate wind loading typical of building entrances; for exposed locations facing prevailing wind or with no canopy protection, contact us before ordering — higher-velocity units may be needed.
How we calculate the recommendation
Match the air curtain width to the door leaf width — not the door frame width. A 1.2 m door leaf typically has a 1.25–1.3 m frame opening; a 1.2 m air curtain covers it with a small overhang on each side, which is ideal. For double doors, measure the combined leaf width. If in doubt, round up to the next size — a slightly oversized unit creates a stronger barrier without wasting significant energy.
Round up, never down. A unit narrower than the door leaves an unprotected strip at each side through which hot air flows in.
Step 2 — height
Nanyoo FM-series units are rated for 2.3–3.0 m mounting height. If the door head is above 3 m, either choose a higher-velocity commercial unit (available on request) or accept a weaker seal. Mount the unit as low as the door frame allows — the air stream loses velocity with every extra centimetre. See the installation height guide.
Step 3 — conditions
- Wind exposure: doors facing open car parks or the sea need higher velocity; consider the next size up or two units.
- Traffic: supermarkets and busy cafés with doors open most of the day benefit from the remote version to run the unit continuously.
- Temperature difference: cold rooms and chiller entrances need refrigeration-grade curtains — contact us.
Worked examples
Pharmacy, single 0.9 m door, 2.4 m head height: 0.9 m sensor unit. Restaurant, double door 1.6 m, 2.8 m head: 1.8 m sensor + remote. Supermarket, 2.4 m sliding entrance: two 1.2 m units. Not sure? Send door photos and dimensions on WhatsApp.
Frequently asked questions
Can an air curtain be wider than the door?
Yes — slightly wider is ideal (e.g. 1.2 m unit over a 1.1 m door).
What if my door is 3.5 m high?
Standard Nanyoo FM units are rated to 3 m; a higher-velocity unit is needed — ask us for options.
Should I buy two smaller units or one large one?
One unit is cheaper and simpler up to 2.0 m; above that, two units are required.
Do I need one for a rear staff door?
If it opens frequently onto outdoor air, yes; a 0.9 m sensor unit is usually enough.
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This guide is general information based on BOTANVÈ catalogue data and widely published HVAC-R practice. It is not a substitute for the equipment manufacturer's installation manual or the advice of a qualified engineer. Prices and availability change; the product page is authoritative.