You can cook without a hood or a vent, but moisture, grease, odors, and heat from cooking on a cooktop can damage the rest of your kitchen.
Also, steam from cooking condenses on windows and walls, and in some cases carbon monoxide from the burning of gas can build up.
A range or cooktop hood or vent will remove most if not all of the above problems.
Hood choices range from basic ductless wall-mount units, to systems with lights, timers, and easy-clean surfaces.
You can buy hidden slim-line hood designs which are concealed under cabinets which slide out when in use. Another kind can be used as a shelf for microwaves with the venting fans underneath. Yet another kind can incorporate a wall-mounted microwave above the range.
Hoods come in many styles, stainless steel, tile, or paneling that matches the cabinetry, for example.
The hood or vent should be at least as wide as the range top.
Most hoods have a fan which moves stale air from inside the hood to the outside through ducts. There are two types of fans; axial, which have blades similar to ordinary fans, and centrifugal, which look like a wheel and can move more air if your ductwork is longer.
Filters will trap grease and small particles, essential to avoid their build-up inside the ducts which could be a fire hazard. Filters should fit well and be easy to remove for cleaning or replacement.
The size of your kitchen and stove will determine the required rate of air removed, which is measured in cubic feet per minute (CFM).
In general for each linear foot of your range you will need to remove 40 CFM. An average size range will require the air removed at 120 CFM.
Types of Hood
Recirculating or Ductless Range Hoods
The most basic but least efficient system. These hoods attach to the wall above the cooktop and pull air through a filter, recirculating it (and odors or gases) back into the room. Filters absorb grease and require frequent cleaning or replacement. These hoods are easy to install because they don’t require ductwork. Should never be used with a gas range.
Pull air through a filter then vent it along ductwork to the outside.
Typically part of the range, often on the stove top near the burners. Some stove designs can be retrofitted for venting from underneath. “Hidden” styles remain flush with the cooking surface until necessary. Then, with the push of a button, they rise 8 to 10 inches above the cooking surface. These are best for island or peninsula cooktops where hood installation may be awkward or impossible.
Downdraft units use one or more fans, pulling air through a filter into ductwork (usually beneath the floor or above cabinets, and sometimes out the wall). They need a minimum of 150 CFM. Stove placement is also a factor; wall units need up to 400 CFM; an island cooktop needs up to 600 CFM.
Cleaning and Maintenance
By design hoods and vents quickly collect dirt and grease and therefore require regular cleaning. Always check the manufacturer’s specific cleaning instructions if available.
Wash external surfaces often with a solution of warm water, detergent, and ammonia. Rinse well with clear water. Don’t use abrasive pads as they will scratch the surfaces.
The (cooled) light bulbs will also need to be cleaned with a sponge dipped in the same solution, rinsed, and allowed to dry thoroughly.
The blades of the fan should also be cleaned with the washing solution if accessible (if not then get them cleaned during annual maintenance by a professional).
Metal mesh filters can be removed and soaked in the solution for a few minutes, then sponged down, rinsed, and dried before replacing in the hood.
Charcoal filters cannot be cleaned and should be replaced once a year.