Every cooker hood does the same first job: pull cooking air through a grease filter. What happens next is where they divide. A ducted hood pushes that air outside. A recirculating hood pushes it through a carbon filter and back into your kitchen.
Ducted wins on performance, every time. The problem is that in a lot of Singapore kitchens it is not on offer.
Why ducting is often not an option
Ducting needs a route to outside air. If the hob sits on an external wall, that is a short run through the wall and the job is easy. If the hob sits on an internal wall or an island, the duct has to travel, usually above the ceiling line or through a bulkhead, to reach a point where it can discharge.
Three things typically stop it. There may be no external wall within a sensible distance. The ceiling void may be too shallow to take a duct of the right diameter once you allow for the bends. Or the building may simply not permit a new penetration in the facade, which is a management or authority question rather than a technical one, and it is worth asking before you commit to a ducted hood.
Long duct runs also cost you performance. Every bend adds resistance, and a hood rated at 600 m3/h in test conditions moves considerably less through six metres of flexible ducting with three elbows in it.
What recirculating actually does
The grease filter catches grease in both systems. The difference is the second stage. A recirculating hood adds an activated carbon filter that adsorbs odour molecules, then returns the air to the room.
What it does well: smell. A working carbon filter makes a real difference to how long last night's dinner hangs around.
What it does not do: remove heat, steam or moisture. Those go straight back into the kitchen. In a Singapore kitchen that is already warm and humid, this is the honest downside, and it is the one people notice most after a month of use.
Carbon filters also saturate. They are consumables, typically replaced every few months to a year depending on how hard you cook, and a saturated filter does nothing at all while still restricting airflow. Factor the ongoing cost in.
How to tell which version you are buying
This is not always obvious from the product name. Some hoods ship convertible, with the recirculating kit sold separately. Others are built for one mode only.
Fujioh is unusually clear about it and encodes the mode in the model suffix. Their FR-SC2090 hood is listed as FR-SC2090R and FR-SC2090V, where the R version is the recycling variant and the V version is ducted. The same pattern runs through the FR-SC2070 and other models in that range. If you are looking at a Fujioh hood, the last letter is doing real work.
For other brands, check the specification and the installation manual for the model, and check whether a carbon filter is included or is an accessory. We list what the manufacturer publishes rather than inferring it.
Extraction rate matters more in recirculating mode
Because you lose efficiency to the carbon filter, a recirculating installation benefits from headroom. Across our cooker hoods the published rates run from 260 m3/h to 1200 m3/h.
At the lower end sit the Fujioh FR-MS2390 and FR-MS2370 at 260 m3/h and the FR-MT1990 at 270 m3/h, along with the Bosch DFT63CA61B and DFT93CA61B at 310 m3/h. Higher up, the Bosch DWB97BK61T reaches 582 m3/h and the DWB91PR50A 602 m3/h. The Teka side goes further still, with the CNL 6415 BK at 730 m3/h, the GFX 72 at 750 m3/h and the GFI 97350 Integra at 766 m3/h.
If you cook with a wok on high heat and you are recirculating, the 260 to 310 m3/h models will struggle. That is not a criticism of those hoods, they are fine for lighter cooking in a ventilated kitchen. It is a mismatch worth avoiding.
Downdraft is a third option
Downdraft extractors rise out of the worktop behind the hob and pull air sideways rather than up. They suit island layouts where a ceiling hood is unwanted, and they still need somewhere for the air to go, so the ducted versus recirculating question applies to them too.
The Teka DDI 90 is rated at 1000 m3/h and the FIH 16760 TOS modular downdraft at 630 m3/h. Both take up space in the cabinet below, which is the real trade.
Practical advice
If you can duct, duct. It removes heat and steam as well as smell and it has no consumable filter. If you cannot, buy more extraction than you think you need, put the hood as close to the manufacturer's minimum mounting height as the manual allows, and open a window when you are cooking hard.
And decide this before you buy the hood, not after, because it changes which model is right. Start from 90 cm cooker hoods if you have the wall run for it, since width and extraction tend to move together.
The cooking that puts a hood under real load
If you want to know whether your extraction is enough, these two are the test cases: char kway teow, which needs a wok held at smoking point, and sambal stingray in banana leaf, which produces belacan smoke an under-specified hood will not clear.
Common questions
Is a recirculating hood worth having at all?
Yes, if the alternative is nothing. It captures grease and reduces odour, which protects your cabinets and your walls. It just will not remove heat or steam, so it is a partial solution rather than an equivalent one.
How often do carbon filters need replacing?
It depends on the model and how much you cook, and manufacturers state their own interval in the manual, usually somewhere between three and twelve months. A saturated filter stops working entirely, so this is a real running cost rather than an optional one.
Can a ducted hood be converted to recirculating later?
Many can, using a recirculating kit from the manufacturer. Whether your specific model supports it is stated in its documentation. Going the other way, from recirculating to ducted, is harder because it needs the duct route that was not there originally.
What does the R or V in a Fujioh model code mean?
On Fujioh hoods, R indicates the recycling version and V the ducted version. So the FR-SC2090R and FR-SC2090V are the same hood in different extraction modes. Check which one a listing refers to.
Does a longer duct reduce performance?
Yes. Every metre of duct and every bend adds resistance, and flexible ducting is worse than rigid. The published extraction figure is measured without a duct attached, so treat it as a ceiling rather than what you will get in your kitchen.