Description
The Elta Twinflow STDL is a twin centrifugal box fan for external mounting, using advanced backward-curved impellers and a redesigned casing that improves airflow efficiency while lowering energy consumption. Available in seven standard sizes from 125mm to 500mm, it delivers air volumes up to 1.740 m³/s and static pressures up to 730 Pa.
Fitted as standard with an EC external rotor motor, it provides stepless speed control via potentiometer or building management system and includes an Auto Changeover Panel for twin-fan operation. Acoustic internal lining minimises noise, the 1.2mm galvanised mild steel casing and ISO 1940-1 balanced impeller ensure durability, and it connects directly to standard flexible or rigid circular ducting (optional rectangular spigots), with a 12-month warranty.
Key specifications
- Sizes: 7 standard sizes, 125mm to 500mm
- Air volume: up to 1.740 m³/s
- Static pressure: up to 730 Pa
- Impeller: advanced backward-curved centrifugal, ISO 1940-1 balanced
- Motor: EC external rotor, IP44, stepless speed control
- Included: Auto Changeover Panel for twin operation
- Casing: 1.2mm galvanised mild steel sheet, acoustic internal lining
- Connection: circular ducting standard, optional rectangular spigots
- Operating temperature: up to +60°C
- Warranty: 12 months
Delivery Information
Made to OrderThis item is made to order. Please allow 15-20 working days for delivery.
Delivery Options
| Service | Estimated Delivery | Cost |
|---|
| Standard Delivery (UK mainland) | Next working day from dispatch | £15.95 +VAT (£7.95 for small items) |
| Free Delivery | Next working day from dispatch | Free on orders over £400 ex VAT |
| Click & Collect | Collect from our Leicester branch | Free |
| Scottish Highlands & Islands | 2-3 working days from dispatch | £36.95 +VAT |
Delivery Area
We deliver to all UK mainland addresses. Scottish Highlands and Islands deliveries may take a little longer. We are not currently delivering to Northern Ireland — Click & Collect remains available.
Questions about delivery? Call us on 0116 246 0031 or email sales@alphaair.co.uk
Returns Policy
Six-Week Returns — No Restocking Fees
We want you to buy with confidence. You can return any standard stocked item within six weeks (42 days) of delivery for a full refund — 100% of the item price, no restocking or handling fees. Trade and business customers get exactly the same rights as retail customers. See our Returns Policy for full details.
Return Conditions
- Items must be unused and in original packaging
- Custom-made, bespoke or powder-coated items are made to your specification and cannot be returned unless faulty
- Items must be returned with proof of purchase
- Return shipping costs are the responsibility of the customer unless the item is faulty
How to Return
- Contact our customer service team to arrange a return
- Pack the item securely in its original packaging
- Include your order number and reason for return
- Ship the item to our returns address
Faulty Items
If you receive a faulty or damaged item, please let us know as soon as possible — ideally within 48 hours of delivery, so we can claim against the courier on your behalf. We will arrange a free collection and send a replacement or issue a full refund. This does not affect your statutory rights.
Questions? Contact us at sales@alphaair.co.uk
