A rangehood display is a wall of stainless rectangles, each with a number in cubic metres per hour on the card beneath it and almost nothing else you could act on. The two specs that decide whether the thing works are the two the card is least likely to carry.
The first is where the air goes. A rangehood either sends cooking air out of the building or passes it through a filter and hands it back to the room, and those are not two settings on a spectrum - they are two different machines wearing one shape. The second is how loud it is at the speed you'd actually use.
This guide settles three things: where your kitchen will let the air go, how much air the hood needs to move, and how to read a noise figure that manufacturers publish inconsistently and shoppers read backwards.
Where the air actually goes
A ducted hood takes cooking air out of the building. Grease, odour, heat and water vapour all leave through the duct. That last one is the part people don't picture: a pot at a rolling boil puts litres of water into the air of your kitchen over an evening, and a duct is the only mechanism here that removes any of it.
A recirculating hood filters the air and returns it to the room. It passes it through a grease filter and then a carbon filter, which takes out grease and much of the odour. It removes no moisture and no heat. The steam off that pot goes up into the hood, through two filters, and back into the kitchen. So does the warmth.
That is the whole fork, and it isn't close on the merits. Recirculating exists because ducting isn't always possible - an apartment with no external wall, a slab ceiling, a rental. It answers a building constraint, not a preference.
Across the 252 rangehoods we list, 218 state which modes they support. Of those, 204 can be ducted and 14 are recirculating-only. 129 document a recirculation conversion: a carbon-filter kit that turns a ducted hood into a recirculating one.
Worth knowing: the other 75 are not sealed against conversion - their spec sheets don't mention it, and a blank is silence, not a no. Thirteen of the 14 recirculating-only models also come from one manufacturer, so read that figure as a description of what we list rather than of what Australia sells.
Then the number that settles it. 24 of the models we list publish both a ducted airflow and a recirculating airflow for the same hood. Recirculating is the lower figure on all 24. Model by model, a hood keeps a median 56% of its ducted airflow when it recirculates; the medians across those 24 are 440m³/h and 872m³/h. Twenty of the 24 come from one manufacturer, so treat the percentage as indicative - but the direction is unanimous across four brands. Air pushed through a carbon filter meets resistance that air pushed down a duct does not. So if you're recirculating, size the hood as though it were a smaller one.
But consider: we can't tell you what any of this costs. Only 8 of the 252 rangehoods we list carry a price and 33 carry an annual energy figure - so no median, no price gap between the modes, and no running cost. Eight prices out of 252 is worse than none.
One more thing, and it's why the fork matters most. If you cook on gas, combustion is happening inside your kitchen. The Climate Council's 2021 report Kicking the Gas Habit: How Gas is Harming our Health attributes up to 12% of the childhood asthma burden in Australia to gas cooktops, and finds that ventilation - an extraction fan, or an open window - reduces that risk without eliminating it. Separately, as a matter of mechanism: grease and carbon filters capture grease and odour, not combustion gases, so a recirculating hood over a gas cooktop hands those gases back to the room. If your cooktop burns something, duct the hood.
What your kitchen will let you install
Mounting type is mostly decided by where the cooktop sits and what's above it. What it costs you in extraction is worth knowing before you make it.
The six mounting types we list, with the number of models stating a noise figure behind each median. A further 12 models state no type.
Slide-out and fixed hoods are the weak end, and by a distance - a median 440 and 250m³/h against 810 for a wall canopy. They're the answers for a small kitchen or a cabinet you don't want to lose, and the least extraction on offer.
The concealed types are the quiet ones. Undermount hoods run a median 59dB across the 18 that state a figure and integrated hoods 62dB across 60, against 66dB for wall canopies - at comparable airflow. The motor sits inside joinery, with cabinetry between it and the room. The undermount count is thin, so read it as a pattern rather than a rule.
Ducting has one spec that matters. Of the 189 models we list that state a duct diameter, 149 specify 150mm and 38 specify 120mm. Long runs and tight bends cost real airflow, and squeezing a 150mm outlet into a 120mm duct throws away extraction you paid for. The box figure is measured on a short straight run.
Pro tip
Check the minimum mounting height before you commit, against your cooktop's fuel. Of the models we list that state both figures, 82 of 96 require more clearance above a gas cooktop than above an electric one - a median 650mm above gas against 600mm above electric. Fifty millimetres decides whether the hood clears the splashback or fouls the cabinet above, and the appliance sets it.
Size it to the kitchen, not to the biggest number
A hood should be at least as wide as the cooktop under it. Steam and smoke rise in a plume that spreads as it goes, so a hood narrower than the cooktop misses the outside burners entirely - which are the ones with the wok on them.
That rule does most of the sizing work, because rangehood widths aren't a continuum. Across the 248 models we list that state a width, they cluster into installation classes with gaps between them: 120 in the 90cm class (850-950mm) and 72 in the 60cm class (570-620mm), with only 12 anywhere between 650 and 850mm. Nothing sits between 621 and 699mm, or between 951 and 1099mm. Above that, 15 models run 1100-1200mm. Below the 60cm class sit 29 narrower ones, 23 of them integrated or undermount units sized to a cabinet rather than a cooktop.
You're picking a class, and your cooktop picks it. Our cooktops guide covers the fuel decision that constrains the bench in the first place - settle that one first if you're replacing both.
For airflow, the models we list run a median 749m³/h at full speed, with the middle half between 604 and 820. The sizing convention is ten air changes an hour: multiply the room's volume in cubic metres by ten. A 3m × 4m kitchen with 2.7m ceilings is about 32m³, which asks for roughly 320m³/h - comfortably inside that range, and a reminder that the biggest number on the wall is not the one you need. Size up if the duct has to travel, and size up again if you're recirculating.
The noise figure nobody prints on the card
Here's the assumption to drop first. Loud is not the price of powerful. Across the 220 rangehoods we list that state both a noise figure and an airflow figure, the two barely relate at all - the correlation between them is 0.08, which is statistically nothing.
Full-speed noise against full-speed airflow, across the 220 models we list that state both. A quieter hood is not a weaker one.
36 of those 220 move 700m³/h or more at 60dB or less, across seven different brands. Quiet and strong is a real combination you can shop for, and not one you can find by reading either number alone - which is why both belong on your shortlist.
Now the figure that changes how you'll live with the hood. The models we list run a median 65dB at full speed and 49dB at their lowest, and across the 133 that state both, the gap runs a median 15dB - roughly the difference between a conversation you can have and one you can't.
That gap is the spec to read, because full extraction is for the wok and the grill, not for every night. The low setting is what you'll be listening to for a decade - and it's the figure less often published. 220 of the models we list state a full-speed level, only 142 a low-speed one.
What you can safely ignore
Fan speeds and warranty. 192 of the 236 models we list that state a speed count have three, and 242 of all 252 carry a two-year parts-and-labour warranty. Neither is a differentiator.
Wi-Fi. 31 of 252 have it. A rangehood is a thing you reach up and touch on your way past the stove.
Branded motor and "smart hood" names. Underneath every proprietary name, a rangehood is a fan, a grease filter, and either a duct or a carbon filter. Find the mechanism; the name is wearing it.
Energy labels. Only 37 of the 252 rangehoods we list carry an energy class, and it's a European letter, because Australia's GEMS scheme doesn't rate rangehoods. It can't be compared with the star rating on your fridge, and there's no efficiency ranking to shop here.
Two things to understand rather than ignore. Perimeter extraction draws air through a slot around the edge of the filter panel instead of through its face, speeding the air up at the intake. 33 of the models we list have it, not enough for us to rank it for you.
And filters are the ongoing job. Baffles get sold as the professional choice, though of the 248 models stating a filter type, 30 use stainless baffles and 213 use mesh or aluminium, and both catch grease. What matters is whether you'll wash it: 116 of the models we list state theirs are dishwasher-safe, the difference between a two-minute job every month or two and a sink full of degreaser. Carbon filters, if you recirculate, get replaced every six to twelve months - 22 models include one in the box, 120 sell it as an accessory.
You now hold the two answers this decision turns on: whether a duct run out of the building is possible, and the width class your cooktop dictates. Everything after that - mounting type, finish, controls, perimeter extraction - narrows a list rather than deciding one.
Take the rangehood quiz and it'll work through the rest against the 252 models we list, with the reasoning shown on every match.
If you want the wider view first, our rangehoods buying guide covers the same specs alongside the full type breakdown.