Range hood blower and grease vent cleaning

Does a range hood duct need to be cleaned?

Yes, and the part that needs it most is the part closest to the hood. A filter catches the grease it can see. The fine mist that gets through rides the airstream until the air slows down, and the first place that happens is the blower and the duct right above it. That section runs warm every time you cook, so the grease that lands there stays soft, then cools and sets between meals. Layer on layer, for years.

There’s a second reason: the air you’re standing in. A gas range puts nitrogen dioxide and fine particles into the kitchen, and the Washington State Department of Health’s guidance on ventilation while cooking is plain about it: a hood that actually moves air is what lowers those levels. A blower dragging a coat of grease moves less air than it did the day it went in. Clean it, and the air in the room is the first thing that comes back.

What’s the “accessible” grease duct, and where does our work stop?

The accessible duct is the section we can reach and see from the hood once the blower is out: the collar where the hood meets the duct, the backdraft damper, and the first run of pipe above it. That’s our scope, and we’re specific because the alternative is pretending.

A duct that goes straight up through the roof from a chimney hood is often short, and we can do most of it. One that runs across a ceiling and out a side wall is a different animal. Past the first section we can’t see what we’re doing. We won’t run rods blind and call it clean; that’s a job for a duct company, and we’ll say so before we start, not after. What you get from us is the blower and the first run done right, plus an honest note on what we saw past our reach.

Buildings change the picture. Pre-war co-op kitchens with recirculating hoods have no duct at all, and brownstone kitchens that vent through the back wall usually have a run short enough for one visit.

How does grease get past the filter?

As mist and vapor, not drips. Cooking fat leaves the pan as droplets too small to see and as vapor that condenses the moment it touches something cooler. A baffle catches the droplets big enough to hit a ridge. A mesh catches a little more. What’s left is too fine for any metal filter, and it goes straight to the blower.

The blower wheel is a drum of curved fins spinning fast, and every fin is a cool surface with a cup on its back side. Grease collects in those cups first. Then it coats the housing wall behind the wheel. Then the duct. Each layer holds the next, and a wheel that’s run for years is out of balance and never quiet about it. Sitting a foot above the burners, that layer is the one thing in the kitchen you’d least want near a flame, which is the plain reason cleaning it cuts the fire risk. We know because we watch it come out.

What are the signs the blower is loaded?

Noise first. A clean wheel spins in balance; a loaded one wobbles, and you hear it as a hum on low that turns into a rattle on high. Then weak draw: hold a sheet of paper under the hood on high, and if it barely lifts, the fan is fighting itself. Then the smell that stays. A hood that’s working carries dinner out of the house; a hood that’s coated hands it back to you in the morning.

That last one is usually the call. A Google review of NY NJ Hoods, our commercial sister company, describes it exactly:

We had a bad smell of grease coming from our vent hood and NY NJ Hoods did a deep clean and made everything look brand new!

The fix was what it always is. Wheel out, housing out, steam, hand-detail, back together, test on every speed. If you’re hearing the rattle, give us a call before it gets louder. The noise is the wheel asking.

Recirculating vs ducted hoods: what changes

A ducted hood sends the air outside. A recirculating hood sends it back into the room through a charcoal pad, so there’s no duct, and people assume there’s nothing to clean past the filter. There is. The blower loads up exactly the way a ducted one does, and the discharge grille on top collects what the charcoal didn’t hold. We open both as part of our residential range hood service.

What we can’t do is turn a recirculating hood into a ducted one; that’s a contractor and, in a building, a board. What we can do is make the one you have pull what it was built to pull, with a proper baffle and mesh filter wash to go with it. Vent-A-Hood is the odd one out, with no filter at all, so Vent-A-Hood’s filterless blower housing gets its own page. Not sure which kind you have? Look at the top of the hood. A grille means recirculating, a pipe means ducted. Send us a photo; the answer fits in two lines.