Time was the only way to vent cooking and food preparation smells out of a kitchen was via an open window, then came the cooker hood, but now the latest method for removing cooking smells is with a downdraft cooktop
In the old days an open window would often as not blow the cooking smells that you’re trying to vent out of the kitchen – right back into it. To avoid this problem you had to get a draught blowing through your house or apartment, so that the through flow of air would carry the smells away. The problem was that the draught could also carry lose papers and other things out, too.
Downdraft Cook Tops
The solution was to extract the fumes via a hood over the cooker which, by the aid of a mechanical fan, sucked the smells and odors upwards into the hood and then vented them to the outside through ductwork.
To this day this is an effective method of clearing smells from the kitchen – but it also means the sight of an ugly hood over the stove/cooker and ugly ductwork along the kitchen walls from the cooker/stove.
The solution is, of course, to somehow suck the fumes and smells downwards, so that the ducting through which the air is expelled can be hidden behind the kitchen cabinets – this is, in all simplicity, how a downdraft cooktop works.
Aesthetically speaking, downdraft cooktops are much easier on the eye than a hood can ever be, as the hood and visible ductwork are immediately removed. That means you’ll have more space available to you for wall cabinets in your kitchen.
The downdraft extractor on a cooktop can be in one of two designs either appearing as a slot, or slots, in the surface of the cooker top (hob) through which the smells and fumes are drawn downwards, or they can be a telescopic style of filter that will ‘pop-up’ at the press of a button on the cooker. They can then be retracted by either pushing them down or again operating the button.
The downdraft slots can be aligned down the middle or sides of the cookertop or might be located at the rear of the cooktop. You would not normally expect to see slots for downdraft cooktops at the front of the hob, to reduce the risk of anything being spilled down them.
Wherever the downdraft slots are there is, of course, always a risk that something could get spilled down them. This makes the telescopic design of downdraft cooktop systems a better one than permanently open slots.
One possible reason for having to have a hood fumes extraction system rather than a cooktop downdraught one is if the hob, or cooktop above a stove, is in an island in the kitchen. The reason for this would arise in particular if you have a solid kitchen floor, as the duct to extract the air would have to be directed under the kitchen floor to reach an external wall.
With a solid kitchen floor this would at least mean extensive extra work, if not prove to be prohibitively costly. In such circumstances a conventional hood with ductwork suspended from the ceiling would be the only realistic choice to make.