Ducting for Cooker Hoods in Singapore Landed Homes: Requirements, Cost & Installation Tips

Installing the right ducting system is the single most important factor in getting strong, consistent suction from your cooker hood — even more important than the brand or suction rating.
For Singapore landed homes, you have far more flexibility than HDB/condos, but proper planning is still required to ensure powerful ventilation, minimal noise, and long-term durability.

This guide explains everything you need to know — from requirements and duct sizing to cost, installation tips and common mistakes homeowners make.

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1. Why Proper Ducting Matters in Landed Homes

Even if you buy a high-end hood with 1,000 m³/h suction, a poor ducting setup can reduce performance by 20–50%.

Proper ducting ensures:

• Stronger suction

• Faster removal of grease, smoke, and odour

• Lower noise levels

• Longer lifespan of the hood motor

• Less oil accumulation inside the system

Landed homes typically allow more flexible venting routes — out the wall, roof, or attic — giving you better airflow if designed correctly.

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2. Key Requirements for Cooker Hood Ducting in Singapore

Here are the minimum requirements most installers follow for good airflow:

✔ 2.1 Duct Diameter: 6” (150 mm) Recommended

Although some hoods can fit 4” or 5” ducts, it is not advisable.

• 6” (150 mm) → Best airflow, lowest resistance

• 5” (125 mm) → Acceptable but restricts some suction

• 4” (100 mm) → Not recommended for modern hoods

A narrow duct = higher static pressure = weaker suction.

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✔ 2.2 Use Rigid Aluminium Ducts Where Possible

Types of ducts:

Whenever possible, insist on rigid ducts.

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✔ 2.3 Keep Ducting Short & Straight

Every bend reduces suction efficiency.

• Each 90° bend = up to 20–30% airflow loss

• Straight duct = optimal performance

If bends are unavoidable:

• Replace sharp 90° bends with 45° elbows

• Ensure curves are gradual

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✔ 2.4 Vent to the Outside – Not Into the Ceiling

For landed homes, make sure the hood duct vents:

• Through an external wall, or

• Upwards through the roof, or

• Into the backyard/side wall

Never vent into:

• False ceilings

• Attics without ventilation

• Enclosed cavities

This will cause mould, heat, and grease build-up.

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3. Installation Options for Landed Homes

Depending on kitchen layout, these are the most common venting methods:

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Option 1: Wall Venting (Most Common)

The duct runs horizontally and exits through an external wall.

Pros:
✓ Shorter distance
✓ Lower cost
✓ Works for most kitchen layouts

Cons:
– Requires hole cut in wall
– May need repainting exterior

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Option 2: Roof Venting

The duct exits through the roof via a roof cowl.

Pros:
✓ Best airflow for upward-venting hoods
✓ Invisible from the side of the house

Cons:
– Higher installation cost
– Requires waterproof flashing
– Best handled by experienced contractors

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Option 3: Through Attic → Roof/Side Wall

Useful when the hood is not backing an external wall.

Pros:
✓ Flexible routing
✓ Cleaner kitchen design

Cons:
– Must ensure attic has proper exit point
– Longer route means more airflow loss

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4. Cost of Cooker Hood Ducting in Singapore Landed Homes

Typical price range (2025 market estimate):

Roof venting usually costs $800–$1,500 depending on roofing complexity.

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5. Installation Tips for Best Performance

✔ Use the shortest duct path

Keep the total distance under 3–4 metres if possible.

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✔ Minimise bends (max 2 bends recommended)

More bends = weaker suction + louder noise.

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✔ Seal all joints properly

Use aluminium tape (not duct tape) to prevent leaks.

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✔ Install a weatherproof external vent cover

Choose one with

• Backdraft flap

• Bird/insect mesh

• Corrosion-resistant materials

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✔ Consider a stronger hood for large kitchens

For big landed-home kitchens, suction of 800–1,200 m³/h provides better performance.

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6. Common Problems Homeowners Face (And How to Avoid Them)

❌ Weak suction despite a strong hood

Cause: Small duct size, too many bends
Fix: Change to 6” duct, reroute for straighter path

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❌ Hood becomes noisy over time

Cause: Grease buildup inside duct
Fix: Professional cleaning every 18–24 months

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❌ Condensation dripping from hood

Cause: Exhaust air cooling too quickly inside duct
Fix: Proper insulation around duct pipes

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❌ Grease stains at wall vent

Cause: No backdraft flap or poor-quality vent cap
Fix: Replace with stainless steel vent cover

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7. Do You Need a Professional for Ducting?

For landed homes, yes — especially if:

• You need wall hacking

• You plan to vent through the roof

• The duct route goes through attic spaces

• You want long-term airflow efficiency

A proper installation ensures:

• No water leakage

• Proper flashing on roof

• Correct duct diameter

• Maximum suction performance

• Compliance with safety guidelines

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8. Summary: What You Must Remember

• Use 6” rigid ducts for best airflow

• Keep the duct short & straight

• Vent outside, not into ceilings

• Avoid more than 2 bends

• Budget $450–$900 for wall vent installations

• Roof venting costs more but offers better airflow

With proper ducting, your cooker hood in a landed home will run stronger, last longer, and remove grease and odour far more effectively.