Read the parts list, not the name: the duct cover listed here is a ductless kit
Reviewed September 2026 · Captivating Cabinets
Prices quoted in this article were read off the grid on the review date; the live price grid on this page governs.
Anyone shopping for a range hood duct cover pictures a painted sleeve that boxes in the pipe between the canopy and the ceiling. That is not what this listing ships. GNK RHBB DCT, at $263.25, is Fabuwood’s recirculating kit: the handful of parts that lets one of the Broan-NuTone internal blowers scrub kitchen air and hand it back to the room when there is no way to send it outdoors. The catalogue label is a filing name rather than a description. So this page answers three questions in turn — what the kit actually contains, whether your kitchen is one of the few that should use it, and, if trim was what you wanted, which parts of this finish do that job.
Five components, and what each one asks of the installer
Our hood CFM guide lists the kit’s contents, and they are all plumbing for air rather than finish carpentry. Laid out in the order the air meets them:
| Component | Its job | Settle before ordering |
|---|---|---|
| 6-to-7″ transition | Enlarges the blower outlet to the kit’s pipe size | That it suits the insert going into your shell |
| 7″ round duct | A short internal run that lifts the air inside the hood enclosure | How much of it your shell and ceiling actually need |
| Charcoal filter | Strips cooking odour once the insert’s own grease filter has done its work | Refills are GNK RHBB FLTR at $71.50 each |
| 90° stack boot | Turns the flow sideways at the head of the run | Clearance above it to the ceiling or soffit |
| Soffit grille | Where the cleaned air re-enters the kitchen | Its size and finish, which our listing does not publish |
Two things fall out of that list. The pipe in this kit never leaves the room: its whole purpose is to carry air a short distance to the carbon and then out through the grille. And the grille must discharge into open air, so its position is a layout decision rather than an afterthought. A grille that ends up hard against the underside of a cabinet or buried behind a closed panel turns the hood into a fan blowing into a box.
On a mid-tone grey the grille is also the one visible metal detail on an otherwise painted enclosure, and a bright grille set into a Nickel soffit draws the eye. Ask what finish it comes in before the drawing is signed off; that is cheaper than living with it.
Ducted or ductless, compared on the things that matter
A vented hood removes air from the house altogether. A kit like this one pulls that air through two filters and blows it back at the ceiling. The gap between those two outcomes is wider than the similar-looking shells suggest.
| Vented outdoors | Recirculated through this kit | |
|---|---|---|
| Grease | Caught by the metal filter, the remainder exhausted | Caught by the metal filter; some gets past |
| Cooking smells | Sent outside | Reduced while the charcoal is fresh |
| Heat and steam | Sent outside | Returned to the kitchen |
| Burner combustion gases | Sent outside | Returned to the kitchen |
| Recurring spend | Washing the grease filter | Charcoal refills on a schedule |
| Makeup-air requirement | Possible above 400 CFM | Not triggered — no air leaves the house |
The fourth row is the one to take seriously. Charcoal does nothing about the nitrogen dioxide and carbon monoxide a gas burner gives off, so over a gas range this kit is the weakest version of the compromise, and over induction or electric it is the most defensible one. Fabuwood’s own hood notes recommend venting every one of its hoods to the exterior and checking local codes first, and codes generally do not accept a recirculating hood as the kitchen’s required exhaust — a ductless kitchen can need a separate exhaust fan to pass inspection. Ask the building department before you plan around it.
The one place recirculation comes out ahead: the 400 CFM line
There is a genuine advantage, and it rarely gets mentioned. A ducted hood that can move more than 400 CFM may trigger a makeup-air requirement in a house with an atmospherically vented gas water heater or furnace inside the air barrier — a second system, with its own cost, added to the job. The parent hood page covers when that applies. Because a recirculating hood sends nothing out of the house, it does not create that pressure problem in the first place.
That is not a reason to choose it if an outside route exists. It is a reason not to be frightened into it by a makeup-air quote, because there is a ducted answer too: the 600 CFM insert can be permanently capped at a lower airflow, down to 300, which keeps a vented hood under the line. The cap cannot be undone, so it is a decision to make once, with the installer and the inspector, rather than a setting to experiment with.
Three things to settle before the drywall goes up
A ductless hood still has a rough-in, just a different one, and all three items are cheap at framing and expensive afterwards.
- The grille’s home. Decide where the cleaned air comes out — a soffit, the face of a chimney, an enclosure over the hood — and draw it, with open air in front of it. Everything above the hood is planned around that one opening.
- Blocking and power. A wood hood with a blower inside it is heavy and wants solid backing in the wall rather than drywall anchors, and the insert needs a circuit wired to code by a qualified installer. Both come off the hood’s mounting drawing, and both are routinely forgotten.
- A way back in. If venting outdoors might become possible later — a building rule changing, a gut renovation of the unit — leave the enclosure above the hood openable. Switching to ducted then means removing the kit and adding pipe, a cap and a damper, not cutting into finished tile.
What a working ductless hood costs in this finish
On the plainest 36-inch box, GNK RHA363021 at $2,418.00, a complete recirculating hood is the shell plus the 400 CFM insert at $903.50 plus this kit at $263.25 — $3,584.75 before installation. What it saves is the ductwork, the exterior cap and the labour to run them, which only your contractor can price. What it adds is permanent: the charcoal is thrown away and replaced, never washed, at $71.50 a time, and the replacement filter page puts a ten-year figure on that. Set the two side by side before deciding the kit is the cheaper route.
Came here for trim? How to conceal a real duct in this finish
If the hood vents outdoors and the question is how to hide the pipe between the canopy and the ceiling, this kit will not help. These will:
- A shell with its own stack. The chimney, designer and slim shells have sectioned chimneys that are trimmed on site, and the curved glass shell’s one-piece chimney trims by up to 12 inches. Trimming only shortens, so on a ten-foot ceiling check the spec-book dimensions against your measured height before ordering.
- A bridge upper over the plain box. A short wall cabinet over the wall-mount hood closes the gap to the ceiling with the duct running behind or through it — the 10x10 package in this finish already puts a 12″ upper over the range. Sizes are on the wall cabinet page.
- A soffit or drywall chase. Framed, finished and painted, it lowers the effective ceiling to meet the hood. It is carpentry rather than cabinetry and the paint will not match the cabinet finish exactly, but on a tall ceiling it is often the tidiest answer.
Panels, scribe and filler to finish any of the three are on the decorative accessories and loose parts pages.
Common questions
- Does GNK RHBB DCT enclose the duct above my hood?
- No. Despite the listing name it is a recirculating kit, not trim. To hide the pipe above a vented hood, choose a shell with a trimmable chimney, hang a bridge wall cabinet over a plain box, or build a painted soffit or chase.
- What comes in the RHBB DCT kit?
- Five parts: a 6-to-7″ transition, a length of 7″ round duct, a charcoal filter, a 90° stack boot and a soffit grille. Together they let a Broan-NuTone insert return filtered air to the kitchen. It is $263.25.
- Does a ductless range hood need makeup air?
- Generally not, because no air leaves the house — that requirement is about hoods exhausting more than 400 CFM outdoors. Confirm with your building department, since codes may also want a separate kitchen exhaust fan when the hood recirculates.
- Is a recirculating kit a good idea over a gas range?
- It is the weakest use of one. Charcoal removes odour but not heat, moisture or the nitrogen dioxide and carbon monoxide that burners produce. Over induction or electric the compromise is much easier to live with.
- Can I convert to a vented hood later?
- Usually, if a route outdoors becomes available: the shell and insert stay, the kit comes out, and duct, an exterior cap and a damper go in. Keep the enclosure above the hood accessible so the change is not demolition.
- What does the kit cost to keep running?
- Only the charcoal, which is replaced rather than washed: GNK RHBB FLTR at $71.50 per change. The insert’s metal grease filter is cleaned and never bought.
Keep reading
The guides behind the numbers on this page.
- Range Hood CFM: How Much Ventilation Your Kitchen Needs
The kit’s contents, the ducted-versus-recirculating comparison and the 400 CFM rule, in full.
- Kitchen Layouts Explained From Single-Wall to G-Shaped
Whether the range can move to an outside wall and skip the kit altogether.
- Kitchen Cabinet Molding Types and Where Each One Belongs
Finishing the top of a hood or a bridge cabinet where it meets the ceiling.
- What Is a 10x10 Kitchen? Cabinet Costs, Packages & Layouts
The package that puts a 12″ upper over the range.
- How Free 3D Kitchen Design Works
Send the reason you cannot vent outside and the grille comes back placed.
