Ducting for 315mm Extractors: The Diameter That Changes Everything

315mm extractor ducting represents the perfect intermediate size between large volumes and discretion. With this diameter, you efficiently manage air extraction in medium-sized grow spaces, while maintaining a compact system. Frankly, it's the sweet spot for many indoor setups.

Why choose 315mm ducting for your extraction

The 315mm diameter offers an excellent compromise between airflow and footprint. Unlike 250mm ducting, which can limit airflow over long distances, 315mm maintains stable pressure even with bends and significant lengths. Extractors of this size typically move between 1500 and 2500 m³/h, perfectly covering the needs of a 3 to 6m² space. The wider cross-section also reduces turbulence, meaning less vibration and parasitic noise.

The 315mm acoustic versions feature a double wall with sound insulation that can reduce noise by 10 to 15 dB compared to standard ducting. This is particularly beneficial when the extractor is running at full capacity. Combiconnect models combine flexibility and rigidity thanks to their internal spiral structure, preventing sagging that can reduce airflow by 20 to 30%.

How to choose your 315mm ducting

First criterion: the length of your installation. For runs less than 5 meters with few bends, a standard flexible aluminum duct will do the job. Beyond that, opt for semi-rigid models or acoustic ducting that better maintain their shape. The internal diameter must exactly match your extractor – precisely 315mm, not 300 or 320mm, which would create leaks.

Second crucial point: thickness. Thin ducting (0.12mm) is suitable for temporary installations, but for long-term use, aim for at least 0.15mm thick. Reinforced versions go up to 0.25mm and are much more resistant to repeated handling. For humid environments, check that the aluminum is anti-corrosion treated.

Finally, consider accessories: hose clamps adapted for 315mm, straight or angled connectors, and possibly silencers if noise remains an issue despite acoustic ducting.

Frequently Asked Questions

What is the difference between Combiconnect ducting and Phonic Trap ducting for 315mm extractors?

The 315mm Combiconnect ducting combines an internal metallic spiral structure with a flexible outer shell, giving it excellent crush resistance while remaining flexible. It maintains its diameter even under strong suction and resists permanent kinks well. The Phonic Trap, on the other hand, focuses on acoustic insulation with its double wall and internal absorbent material that significantly reduces noise pollution. In terms of airflow, the Combiconnect is slightly superior due to its smooth inner wall, while the Phonic Trap prioritizes acoustic comfort at the cost of a slight pressure drop.

Is this 315mm ducting compatible with my Iso Max 315 extractor?

Yes, all 315mm ducting is compatible with the Iso Max 315 extractor, which indeed has a 315mm diameter outlet. The important thing is to securely fasten the ducting with an appropriate hose clamp to prevent it from detaching under suction. Since the Iso Max develops significant airflow (up to 2380 m³/h), opt for quality ducting that will not collapse under negative pressure. Ducting that is too thin or poorly secured can reduce extractor performance by 15 to 20%. Also, ensure that the total length of ducting does not exceed 15 meters to maintain optimal efficiency of your Iso Max.

What is the pressure loss over 10m of ducting for a 315mm extractor?

Over 10 meters of straight 315mm ducting, expect approximately 15 to 25 Pascals of pressure drop depending on the type of ducting and the extractor's airflow. Smooth ducting generates less resistance than spiral or acoustic ducting. Each 90° bend adds the equivalent of 1.5 to 2 meters of straight ducting in terms of pressure loss. With an extractor moving 2000 m³/h, this loss represents about 10% of the available static pressure. To minimize these losses, avoid kinks, maintain a wide bend radius (minimum 30cm), and use appropriate connectors rather than sharply bending the ducting.

How to install 315mm ducting without leaks or excessive kinks?

Start by completely unrolling the ducting before installation to eliminate any shape memory from packaging. First, secure it to the extractor side with a metal hose clamp, not just adhesive tape which can fail under pressure. Stretch the ducting without pulling it excessively – it should follow a natural path with gentle curves. For changes in direction, use pre-formed elbows rather than bending the ducting, which would create constricted areas. Secure the ducting every 1.5 to 2 meters with clamps or straps to prevent it from sagging. At the outlet, ensure the end is well-sealed and oriented to prevent air or moisture backflow.

Should 315mm extractor ducting be cleaned and how?

Annual cleaning is recommended, especially if you notice a drop in airflow or persistent odors. Disassemble the ducting and wash it with lukewarm water and a mild detergent, avoiding abrasive products that could damage the aluminum. For acoustic ducting, be careful not to soak the internal insulation. A simple rinse followed by complete drying is usually sufficient. Greasy or dusty deposits can be easily removed with a soft brush. Take advantage of the cleaning to check the overall condition: micro-perforations, wear areas, loose clamps. Ducting in good condition can last 5 to 7 years with normal use, but excessive humidity or frequent handling reduces this lifespan.