Which kind of hood do you have?

Turn the fan on high and check these in order.

  • IfAir blows out of slots at the top front of a microwave above the rangeThenIt is set to recirculate. Odor goes through a small charcoal filter, if one is installed, and back into the room.
  • IfNothing blows into the room and you can feel air leaving through an exterior wall or roof cap outsideThenIt is ducted outdoors. If smell still lingers, look at fan speed, filter cleanliness and how long it runs.
  • IfThere is a duct above the cabinet but air still comes back into the kitchenThenThe unit may have been installed in recirculating mode despite the duct. Its manual explains how the blower plate is turned for outside venting.
  • IfYou cannot find any exterior cap and the kitchen sits in the middle of the floor planThenRecirculation may have been the only option the builder chose. Ask an HVAC or kitchen contractor whether an exhaust route is practical.

Why recirculation is so common in attached homes

In an attached home, a kitchen may sit against a shared wall or near the center of a unit, far from an exterior wall. Running a duct outdoors could involve a ceiling route, a rated assembly, or association approval for a new exterior opening. A recirculating microwave hood avoids those construction questions, but whether that arrangement exists in a particular Lowry home must be checked at the appliance rather than assumed from the address.

The charcoal filters in these units are thin and small. They can take the edge off light cooking when new, but they saturate quickly and are frequently missing altogether. The fan then simply moves greasy, aromatic air around the kitchen and toward the stairs. Heavy searing, deep frying, fish and long-simmered spice blends overwhelm even a fresh filter.

Over months and years, that recirculated air leaves a thin film of cooking oils on cabinet faces, the ceiling above the range, upper walls, window coverings and the fabrics in nearby rooms. The film holds aroma long after the meal, which is why a kitchen can smell of cumin or fried fish on a morning when nothing has been cooked.

Options from simplest to most involved

OptionWhat it doesLimits
Replace the charcoal filterRestores what little odor capture the unit hadShort-lived; still returns air to the room
Run the fan longer and higherMoves more air across the filter and helps mixingDoes not remove odor from the house
Open a window or run a bath fan while cookingCreates an outward path for cooking airWeather-dependent; bath fans are small
Cover pots and use lower heat for searingReduces the amount of oil and aroma releasedChanges cooking habits
Convert to outside venting where a duct route existsRemoves cooking air from the homeMay need a contractor and, in an association, written approval
Clean the film already built upRemoves stored odor from cabinets, walls and fabricsNeeded once even after the hood is fixed

Before you ask anyone about changing the hood

Common questions

Will a stronger recirculating unit fix the problem?

Usually not. More airflow through a small carbon filter still sends most aroma back into the room. Getting air outdoors is what makes the real difference.

General information for Lowry, not a quote or professional advice. In an emergency, call 911.