Cooker hoods
This category holds cooker hoods from integrated ones fifty-two centimetres wide to wall and chimney hoods of ninety, with an extraction rate of two hundred and fifty to eight hundred cubic metres per hour. The first choice is between ducting outside and recirculation, because only ducting takes the moisture out of the kitchen as well. The width should be at least that of the hob, or the steam escapes to the sides. And work the rate out from the volume of the kitchen times ten, and on recirculation reckon on roughly double.
Cooker hoods
This category holds cooker hoods from integrated and canopy models to wall, angled and chimney hoods, in widths of fifty-two, sixty and ninety centimetres. The extraction rate runs from two hundred and fifty to eight hundred cubic metres per hour and the energy classes from A+ to A+++. Most have LED lighting and button or touch controls, and some of them handle ducting as well as recirculation. The height above the hob is laid down by the maker and with gas it tends to be greater than with electric, so go by the manual on that.
The first thing is ducting outside against recirculation. A ducted hood blows the air out through a pipe, so the smell, the grease and the moisture leave the kitchen. A recirculating one puts it through the grease filter and the carbon filter and gives it back to the room, so it takes the smell away but leaves the water vapour in the kitchen. Ducting is therefore chosen wherever there is something to drill through, and recirculation where there is not, in a flat in the middle of a building for instance.
The second is the width to match the hob. The hood should be at least as wide as the hob beneath it, because whatever hangs over its edge escapes to the sides. A hob of sixty centimetres therefore takes sixty and one of ninety takes ninety, and wider never hurts. Integrated models come out a little narrower, fifty-two or fifty-nine point five centimetres, because they hide inside the cabinet.
The third is the rate in cubic metres per hour. Work out the volume of the kitchen, that is length times width times height, and take it times ten, which gives you the minimum. With an open plan or frequent frying reckon on twelve, so twenty-five cubic metres come out at two hundred and fifty to three hundred cubic metres per hour. On recirculation one multiplies by about twenty, because the air goes round in a loop, and there you therefore need a distinctly stronger machine.
The last one is the grease filter against the carbon filter. The metal grease filter catches the grease, it comes out and goes in the wash and so lasts the whole life of the appliance. The carbon filter binds the smell instead, it gets used up and gets thrown out after a while, and you need it only when you are running on recirculation.