A duct pipe is the backbone of any ventilation system. Whether you are exhausting bathroom moisture, channelling kitchen fumes, or distributing conditioned air through an HVAC system, the quality and correct sizing of your duct pipe determines how well your ventilation actually works.
This guide covers everything you need to know about duct pipes in the Indian context — types, sizes, materials, installation, and how to buy the right one.
What Is a Duct Pipe?
A duct pipe is a flexible or rigid channel used to transport air through a ventilation, exhaust, or HVAC system. It connects fans, air handling units, and exhaust points to move fresh, stale, or conditioned air efficiently from one space to another.
Duct pipes are essential in:
- Bathroom and kitchen exhaust ventilation
- HVAC air distribution systems
- Industrial fume and heat extraction
- Grow room and hydroponics ventilation
- ERV and HRV fresh air systems
Astberg PVC Flexible Duct Pipe — Built for Indian Conditions
Astberg offers PVC flexible insulated duct pipes designed for residential and commercial ventilation in India. Our duct pipes resist moisture, maintain shape under pressure, and significantly reduce airflow noise — making them the preferred choice for silent ventilation setups.
Available Sizes:
- 100mm (4 inch) — ideal for bathroom exhaust fans
- 125mm (5 inch) — suited for kitchen ventilation
- 150mm (6 inch) — HVAC and inline fan connections
- 200mm (8 inch) — commercial air distribution
- 315mm (12 inch) — industrial and high-volume exhaust
Key Features:
- Thick grey PVC outer layer — prevents light leaks in grow rooms
- Multi-layer aluminium foil inner core — heat resistant and durable
- Insulated construction — reduces condensation and thermal loss
- Flexible design — bends around corners without airflow restriction
- Compatible with all standard inline fans, ceiling exhaust fans, and HRV/ERV units
Types of Duct Pipe: Which One Do You Need?
| Type | Material | Best For | Temperature Range |
|---|---|---|---|
| PVC Flexible Duct | PVC + Aluminium | Homes, offices, grow rooms | Up to 60°C |
| Insulated Flexible Duct | PVC + Foam insulation | HVAC, condensation-prone areas | Up to 60°C |
| Rigid Aluminium Duct | Aluminium | Commercial, industrial | Up to 200°C |
| Semi-Rigid Aluminium | Aluminium | Kitchen exhausts | Up to 120°C |
Astberg specialises in PVC flexible insulated duct pipe — the most versatile and widely used type for Indian residential and light commercial applications.
How to Choose the Right Duct Pipe Size
Selecting the correct duct pipe diameter is critical for airflow efficiency. Undersized ducting causes back pressure that reduces fan performance. Oversized ducting wastes installation space and can reduce air velocity.
Sizing Guide:
- 100mm duct pipe → Use with fans rated 80–150 m³/h (bathroom, small room exhaust)
- 125mm duct pipe → Use with fans rated 150–250 m³/h (kitchen, medium rooms)
- 150mm duct pipe → Use with fans rated 250–400 m³/h (large rooms, inline duct fans)
- 200mm duct pipe → Use with fans rated 400–700 m³/h (commercial spaces)
- 315mm duct pipe → Use with fans rated 700–1500 m³/h (industrial extraction)
Rule of thumb: Always match the duct pipe diameter to the outlet diameter of your fan or air handling unit.
Installation Tips for Duct Pipe
- Minimise bends — every 90° bend reduces airflow by approximately 20%. Use gradual curves where possible.
- Secure with duct clamps — avoid loose connections that cause noise and leakage.
- Seal all joints with aluminium foil tape — not standard masking tape, which degrades over time.
- Keep runs short — every additional metre of duct pipe adds resistance. Keep total duct length under 5m where possible for domestic fans.
- Insulate in cold climates — uninsulated duct in cold spaces causes condensation inside the pipe, leading to moisture damage and reduced airflow.
Why Buy Duct Pipe from Astberg Ventilation?
Astberg Ventilation is an India-based ventilation specialist offering premium European-standard products tailored for Indian climates and building types.
- PAN India delivery — ships within 5 working days
- Free shipping on orders above ₹5000
- Expert support — ventilation advice by phone and WhatsApp
- Manufacturer warranty on all duct pipe products
- Compatible accessories — duct clamps, bends, junctions, cowls, and fans all available from one supplier
📞 Toll Free: 1800-5727-801 📧 info@astbergventilation.com 📍 Ludhiana, Punjab, India
FAQ
Q: What is a duct pipe used for? A: A duct pipe is used to move air through a ventilation or exhaust system. It connects fans, vents, and air handling units to exhaust stale air from bathrooms and kitchens, supply fresh air to rooms, or distribute conditioned air in HVAC systems. Duct pipes are used in homes, offices, commercial buildings, and industrial facilities across India.
Q: What size duct pipe do I need for a bathroom exhaust fan? A: For most bathroom exhaust fans in India, a 100mm (4 inch) duct pipe is the standard size. If your fan has a 125mm outlet, use 125mm ducting. Always match the duct diameter to the fan's outlet port — using a smaller diameter creates back pressure and reduces performance.
Q: What is the difference between flexible duct pipe and rigid duct pipe? A: Flexible duct pipe is made from a spiral wire core wrapped in aluminium foil and PVC, allowing it to bend around obstacles — ideal for home installations. Rigid duct pipe is made from solid aluminium or galvanised steel and is used in commercial HVAC systems where long, straight runs are needed. For most Indian residential applications, flexible PVC duct pipe is easier to install and sufficient for performance needs.
Q: Can duct pipe be used for kitchen exhaust? A: Yes. A 125mm or 150mm PVC flexible duct pipe is commonly used for kitchen exhaust ventilation. For chimney hood connections, semi-rigid or rigid aluminium duct pipe is recommended as it handles higher temperatures from cooking exhaust. Astberg offers duct pipe suitable for both kitchen inline fans and chimney exhaust.
Q: How long can a duct pipe run be? A: For residential exhaust fans (bathroom/kitchen), the maximum recommended duct pipe run is 3–6 metres with minimal bends. Longer runs reduce airflow significantly. For inline fans with higher static pressure, runs up to 10–15 metres are possible. Always calculate the total equivalent length (actual length + bend equivalents) when designing a duct system.
Q: What is insulated duct pipe? A: Insulated duct pipe has an additional foam or fibreglass insulation layer between the inner aluminium foil and the outer PVC jacket. Insulation prevents condensation forming on the pipe surface in humid or cold conditions, reduces heat loss in HVAC supply ducts, and lowers airflow noise. Astberg's flexible duct pipes feature built-in insulation for all these benefits.
Q: How do I connect duct pipe to a fan? A: Slide the duct pipe end over the fan's outlet spigot, then secure it with a jubilee clip (duct clamp) tightened around the outside of the pipe. Seal the joint with aluminium foil tape for an airtight connection. Never use standard plastic tape — it degrades in heat and humidity.
Q: What is the price of duct pipe in India? A: Duct pipe prices in India vary by size and material. A 10-metre roll of 100mm PVC flexible insulated duct pipe starts at approximately ₹1,750 from Astberg Ventilation. Larger diameters (150mm, 200mm, 315mm) are priced higher. Astberg offers free shipping on orders above ₹5,000 with PAN India delivery.
Q: Is PVC duct pipe safe to use indoors? A: Yes. PVC flexible duct pipe used for ventilation is manufactured to be non-toxic and safe for indoor use at normal operating temperatures (below 60°C). It does not release harmful fumes during standard ventilation operation. Astberg's duct pipes comply with ventilation product safety standards.
Q: Where can I buy duct pipe online in India? A: Astberg Ventilation offers PVC flexible insulated duct pipes online in India at astbergventilation.com, with sizes from 100mm to 315mm available. Orders ship PAN India within 5 working days, with free shipping on orders above ₹5,000. You can also call 1800-5727-801 for expert assistance in choosing the right duct pipe for your project.
