Pull out the filter or filters, which might involve pushing them up, so you can tilt them enough to maneuver past the ledges where they sit. With the filters out, peer into the space where the fan runs. Although there are YouTube videos showing how to remove the blades to clean them (after the unit is unplugged), cleaning instructions that come with hoods do not suggest doing that.
Dorian Olsen, who staffs the technical services line for the Viking Range Corporation, said to wipe out whatever grease you see. “If the filters are cleaned regularly, there shouldn’t be much,” he said. If you see a lot of built-up grease, call a professional duct-cleaning service or a company that services appliances, and ask for someone to check the fan housing and the duct to the outdoors.
Typically, the innards of the fan don’t need attention, and you can focus on cleaning the hood and its cover, starting with the areas around the filters. Immerse a cloth or sponge in hot water mixed with a little hand dishwashing detergent. Wring out the cloth or sponge enough so it doesn’t drip. Wipe an area, refold the cloth or rotate the sponge, then wipe the next area. Rinse and repeat as needed. You should also wipe along the ledges where the filters sit. (For corners, use an old toothbrush.)
If warm, soapy water doesn’t cut through the grease, put on rubber gloves and add baking soda or vinegar to the water. For especially stubborn deposits, use a degreaser, such as Formula 409 cleaner or Simple Green, Olsen said.
If your hood is painted, be careful not to use anything abrasive, he said. Stainless-steel hoods aren’t as tender, but if you scrub with something abrasive in a direction that doesn’t match the way the stainless steel was finished, you will see scratches. And avoid using anything with chlorine, which can damage the protective layer on stainless steel.
Once the grease is off, go over the surfaces again with a cloth or sponge dampened in clean water, then dry with a soft cloth. Afterward, turn your attention to the outside surfaces of the hood. Clean them the same way, starting at the top and working down, so you don’t dribble on an area you just cleaned. Grime collects mostly on the hood, not the chimney section, so if you clean frequently, you might be able to focus on the sloping surfaces and skip the vertical parts most of the time.
If you have a stainless hood and it still seems streaked after you’ve rinsed and dried, Olsen suggests spraying WD-40 on a cloth and polishing with that. Or you could use a stainless-steel cleaner and polish, which probably contains oil. A thin layer of oil will make stainless steel look unblemished, but know that an oily surface will collect dirt and grease, so you might have to clean more frequently.
Besides cleaning the hood, you also need to attend to the filters. Hoods that vent to the outdoors have filters that can be washed and reused. There are two basic types: baffle and mesh. The baffle style, made of stainless steel, has two layers of three-sided channels that run horizontally but with the peaks of the channels oriented in opposite directions. The top layer, which has the peaks pointed upward, changes the direction of the airflow, causing the grease to settle out, while the lower layer, with the peaks pointed down, collects that grease. The mesh filters are often made of aluminum, and they depend on their fine filaments to trap grease.
The easiest way to clean stainless-steel filters is by running them through a cycle in the dishwasher. Aluminum filters may also be safe to clean in a dishwasher, but some dishwasher detergents are quite alkaline and can eat into aluminum. Julie Nelson, who answers technical-support questions for Broan, a range-hood manufacturer, said she would clean an aluminum filter in the sink with hot water and hand dishwashing detergent, such as Dawn. Letting the filter soak generally makes the grease soft enough to rinse off — unless there is years’ worth of built-up grease, she said. In that case, she would replace the filters.
Range hoods that aren’t ducted to the outdoors usually have filters with metal mesh on the side that faces the range, topped by a charcoal pad. Sometimes the layers are packaged together; with other filters, the layers are separate. Because you can’t clean the charcoal, if your hood uses single-unit filters, you will periodically need to replace them. If the mesh is separate, you can wash that and replace the charcoal layer.
Some hoods have indicator lights to signal when filters need to be changed. Otherwise, a calendar might be your best guide. Nelson said Broan recommends replacing filters in ductless hoods every five months, but some Broan product literature suggests three to six months. Bosch, which has filters with separate layers for at least some of its range hoods, suggests replacing the charcoal filter when it becomes noticeably dirty or every six to 12 months, depending on use. But literature for one hood model that’s equipped with sensors says the “time to clean” light will go on for the grease filter after 30 hours of use and the “time to replace” light will go on for the charcoal filter after 120 hours of use .
In the end, the timing really depends on how often you cook and whether you do a lot of frying.
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