Sizing a chimney properly
| Kitchen | Hob | Recommended suction | Chimney width |
|---|---|---|---|
| Small closed kitchen, under 60 sq ft | 2 – 3 burner | 1,000 – 1,200 m³/hr | 60 cm |
| Standard Mumbai kitchen, 60 – 100 sq ft | 4 burner | 1,200 – 1,400 m³/hr | 60 cm |
| Open kitchen into a living area | 4 burner | 1,400 – 1,600 m³/hr | 90 cm |
| Island hob | 4 – 5 burner | 1,500 – 1,800 m³/hr | 90 cm island hood |
| Heavy daily frying, joint family | 5 burner | 1,500 – 1,800 m³/hr | 90 cm |
The hood should be at least as wide as the hob, and ideally one size wider. A 60 cm hood over a 4-burner hob loses smoke at the front burners.
Market bands observed in Mumbai
| Type | Band we observe | Comment |
|---|---|---|
| Wall-mounted, 60 cm, baffle filter | ₹12,000 – 22,000 | Entry to mid |
| Wall-mounted, 60 cm, auto-clean | ₹18,000 – 32,000 | The common Mumbai choice |
| Wall-mounted, 90 cm, auto-clean | ₹22,000 – 42,000 | Open kitchens |
| Island hood, 90 cm | ₹35,000 – 70,000 | Needs a ceiling duct route |
| Built-in / concealed hood | ₹20,000 – 48,000 | Hidden inside a wall unit |
| Ducting kit, 150 mm rigid | ₹2,500 – 9,000 | Frequently omitted from quotations |
Buying observations only, not official pricing. Installation is usually ₹1,500–4,000 extra unless the kitchen contractor includes it.
Ducting: where most installations are lost
A chimney’s rated suction is measured in free air. Every metre of duct, every bend and every restriction reduces what reaches your kitchen.
- Use 150 mm rigid duct wherever possible. Flexible aluminium hose is convenient and its corrugations cost you a substantial share of the airflow.
- Keep the run short and straight. Under three metres with no more than two bends is the target. A 90-degree bend is roughly equivalent to two metres of straight pipe.
- Discharge into the shaft or through an external wall, never into the false ceiling void. Discharging into a ceiling void deposits grease above your head and eventually smells.
- Fit a non-return flap at the discharge so the shaft does not push cooking smells back into your kitchen from a neighbour’s flat.
- Plan the route before the ceiling is designed. A duct discovered after the reflected ceiling plan is signed is how a bulkhead appears in the wrong place.
Filters, cleaning and Mumbai realities
- Baffle filters separate oil by changing the direction of the airflow. They work well with Indian cooking and need washing every three to four weeks in a household that fries daily.
- Auto-clean hoods collect oil into a removable tray with a heated cycle. They reduce the frequency of filter washing rather than eliminating maintenance; the tray still needs emptying.
- Mesh filters clog quickly with Indian cooking and are not our recommendation.
- Recirculating hoods with carbon filters remove smell but not heat or humidity, and the filters are a recurring cost. Use only where ducting is genuinely impossible.
- Society rules sometimes restrict new penetrations through external walls. Check before designing a duct route through the facade.
Our position
Greenbox is an independent design and build studio. We are not a dealer, distributor, service partner or channel partner for Faber or for any appliance manufacturer. We specify appliances on merit, buy through Mumbai dealers at market rates, and pass through supplier invoices where we procure for a client. The bands above are what we observe in the market, not the manufacturer’s official prices, and any product warranty is the manufacturer’s on its own terms.
Specification summary
| Element | Specification |
|---|---|
| Suction | 1,200 – 1,600 m³/hr for most Indian kitchens |
| Width | At least as wide as the hob; one size wider is better |
| Mounting height | 650 – 750 mm above the hob surface |
| Duct | 150 mm rigid, under 3 m, maximum two bends |
| Discharge | To shaft or external wall, with a non-return flap |
| Filter | Baffle or auto-clean; not mesh |
| Electrical | Dedicated 16A point above the hood position |
Frequently asked questions
How much suction do I actually need?+
For a standard closed Mumbai kitchen with a four-burner hob, 1,200–1,400 m³/hr is ample. Open kitchens and heavy frying justify 1,500–1,800. Buying a higher number and then running it through a long flexible duct with three bends gives you less usable suction than a modest hood ducted well.
Is auto-clean worth the extra money?+
In a household that fries daily, yes — it reduces filter washing from a monthly chore to an occasional one. It does not eliminate maintenance; the oil collector tray still needs emptying, and neglecting it is the most common cause of a smelly kitchen with an expensive hood.
Is Greenbox a Faber dealer or service partner?+
No. We are an independent studio with no dealership, distributorship or service arrangement with any appliance manufacturer. We specify on merit, buy through the open market, and pass through invoices when we procure for clients.
Where should the chimney discharge?+
Into the building shaft or through an external wall, with a non-return flap at the outlet. Never into the false ceiling void — grease accumulates above the ceiling, it eventually smells, and cleaning it means opening the ceiling.
How high above the hob should it be mounted?+
650–750 mm above the hob surface. Lower and tall people hit their heads on it; higher and the capture efficiency drops sharply. The height is measured from the hob surface, not the counter, and it should be set before the wall units are fixed.