Keep Air Moving Through Your Home

A home moves air in three places you can check in twenty minutes: the hood over the stove, the fan in the bathroom, and the vents that carry conditioned air room to room. None of it is complicated work, but each one has a right answer that is easy to get wrong by assuming instead of checking.

Start with the range hood

A range hood only does its job if you know which kind you have, because the two types need different maintenance and one of them isn't removing anything from the house.

A ducted hood pulls air through a metal grease filter and sends it outside through ductwork, usually to a wall or roof cap. The metal filter is reusable: wash it in warm, soapy water on the schedule in the manufacturer's instructions, or run it through the dishwasher if the manual allows it.

A ductless, or recirculating, hood pulls air through a charcoal filter that traps odor and grease, then blows the same air back into the kitchen. Charcoal filters aren't washable. They get replaced on the schedule in the manufacturer's instructions, and replacing them is the only maintenance that does anything, since a saturated charcoal filter stops capturing odor even though the fan still runs.

If you don't know which one you have, look above the cooktop for ductwork running to an exterior wall or the roof. No visible duct usually means recirculating. The model number on the hood, matched to its manual, will settle it either way. The U.S. Environmental Protection Agency recommends that a range hood capture and exhaust cooking exhaust directly outdoors, which only a ducted hood does; a recirculating hood filters the air but leaves the moisture and byproducts of cooking in the house.

Test and clean the bathroom exhaust fan

Two things matter for a bathroom fan: whether it's actually moving air, and where that air goes.

Turn the fan on and hold a single tissue or a small square of toilet paper near the grille. A working fan pulls the tissue toward it and holds it there. If the tissue barely moves, or doesn't move at all, the fan isn't pulling meaningfully even if it sounds like it's running.

With the fan off, vacuum or brush the dust off the grille and, if the manual shows how to remove it safely, the blades behind it. A grille clogged with dust and lint restricts airflow the same way a blocked filter does. Stop if anything beyond the grille looks like it requires opening electrical housing; that's outside routine cleaning.

Confirm where the fan actually vents. The EPA advises that bathroom exhaust air should be sent directly outside, not just into an attic or some other space inside the house. Venting into an attic instead of outdoors pushes bathroom moisture into a space where it can condense and cause damage you won't see from the bathroom. If you can access the attic safely, look for ductwork from the fan running to a roof or wall cap. If you can't confirm it yourself, that's a reasonable question for a home inspector or HVAC contractor.

Keep supply and return vents clear

Walk each room and check both kinds of vent: the supply registers that blow conditioned air in, and the return grilles that pull air back to the system. Furniture, rugs, curtains, and storage boxes block both, and a blocked return can restrict airflow for the whole system, not just the one room.

While you're checking, notice whether any room runs noticeably warmer or colder than the rest of the house on the same thermostat setting. That's worth writing down: which room, what time of day, and what season. It's useful information for whoever eventually looks at it, but it isn't something to diagnose yourself. Uneven temperatures can come from duct design, insulation, equipment sizing, or several other causes that a technician sorts out with tools and access you don't have. Clearing the vent is the homeowner task; explaining why one room still runs hot or cold after that is not.

Record what you find

Filter sizes, model numbers, and the last date you cleaned or replaced something are exactly the kind of detail that's inconvenient to rediscover. Add the range hood filter type and size, the bathroom fan's confirmed exhaust destination, and any rooms with a persistent temperature difference to your home record so the next person checking, including you in six months, isn't starting from zero.