If you have an exhaust fan above your stove, you should turn it on when you turn on your burners or oven, whether they are gas or electric. Though many people use their fans only when they burn something, these devices remove heat and odors and help keep moisture and grime from accumulating on surrounding surfaces.
More important, they’re designed to remove ultra-fine airborne particles created when foods are cooked—a source of indoor air pollution. They also reduce nitrogen dioxide, carbon monoxide and other potentially hazardous byproducts produced by gas burners. In fact, gas cooking burners can produce pollutants at levels that exceed health-based standards, especially in an airtight room. The biggest concern is for restaurant workers, who may be exposed to cooking and gas fumes for hours on end, but even home cooks can be at risk if the pollutants are not properly vented.
Which range hoods are best?
A recent study from the Lawrence Berkeley National Laboratory in Berkeley, published in Environmental Science & Technology, evaluated seven models, ranging in price from $40 to $600. It rated their performance on several variables including fan efficiency (how well they move air), capture efficiency (how well they remove pollutants) and sound (many people don’t use the fans because they’re noisy). No device fared well on all variables—for example, those that captured more contaminants and were quieter had poorer fan efficiency, while the one that removed the most pollutants was very loud.
But as the paper summed it up, even a moderately effective range hood can substantially reduce your exposure to pollutants—especially if you use higher fan settings and cook on the back burners. According to Brett Singer, one of the study’s authors, cooking on the back burners with a venting hood can actually double the capture efficiency for standard low-cost hoods.
For the best performance, the hood should be placed at manufacturer-recommended height above the top of the stove (usually 24 to 30 inches) and vented to the outside. If you can’t vent to the outside, there are also recirculating hoods that suck air through filters and blow it back into the kitchen. These may catch grease, but they have not been shown to be effective at removing pollutants. The nonprofit Home Ventilating Institutecertifies home ventilation systems to ensure that they meet industry standards (there are no government standards). Some products carry Energy Star labels—though the standards do not address removal of pollutants.