90° Oval-to-Round Elbow (Oval Duct)
The elbow that turns 90° and goes from oval to round duct in one piece.
AirGreen codeAG-VC-02301
514 316-2973 · sales@airgreen.ca
Quick facts
The 90° oval-to-round elbow combines two functions: it turns the duct at a right angle and it goes from oval duct to round duct. A single piece therefore replaces an elbow and a transition fitting. It is available in 5 and 6 in.
The key fitting in a riser to the upper floor
In a multi-storey house, the branch leaves the main duct in the basement as round duct, then rises as oval duct inside a wall cavity. The meeting point is at the foot of the wall, often in a very tight space between the sole plate and the joists. The oval-to-round elbow makes the turn and the transition at that exact spot, with less length and one joint fewer than a two-piece assembly. It can also be used at the top of a riser that ends on a round duct, or to connect an oval duct to a unit’s round collar.
Choosing the size
Take the size of your oval duct, 5 or 6 in. The round side takes the round branch of the matching size; if your branch has a different diameter, add a reducer or consult us.
Installation
- Identify the oval side and the round side before cutting the sole plate or the floor.
- Screw both joints and seal them with aluminum tape or mastic.
- Make this connection before closing the wall: it will no longer be accessible afterwards.
Installed by AirGreen across Greater Montréal
We build risers to upper floors and their connections in Montréal, Laval, Longueuil, on the South Shore and on the North Shore. RBQ licence 5645-9605-01, subcategory 15.8 Ventilation. For availability or a quote, call us at 514 316-2973 or email sales@airgreen.ca with the size and quantity you need.
Where the wall meets the basement
At the bottom of a riser, the oval duct in the wall often has to turn and meet a round branch: this elbow does both at once.
- Bottom of an oval-duct riser, connected to a round branch
- Top of a riser that ends on a round duct
- Connecting an oval duct to an appliance’s round collar
- Mixed round and oval forced-air and air exchanger systems
2 sizes, one page
Each size has its own AirGreen code. Tap a row to select it.
Size of the oval duct and of the matching round duct.
Specifications
From the manufacturer’s documentation. A value the manufacturer does not publish is not listed.
What to know before installing
- Choose the oval duct size; the round end takes the matching round branch.
- Note which end is oval and which is round before planning the route.
- Dry-fit the elbow in the cavity before cutting the plate.
- Screw and seal both joints.
You may also need
Galvanized Oval Duct – 60 in Length
Galvanized Round Pipe – 60 in Length
Oval 90° Vertical Elbow (Oval Duct)
Universal Oval-to-Round Fitting (Oval Duct)
Galvanized Side Take-Off
Galvanized Round End Cap
Cleats for Galvanized Duct (C and S)
45° Flat Oval Elbow (Oval Duct)Ventilation ductsSee all
Frequently asked questions
Why an oval-to-round elbow instead of an elbow and a transition?
It makes the turn and the transition in one piece: less length and one joint fewer to seal.
Where does it usually go?
At the bottom of a wall riser, where the oval duct turns to meet the round branch in the basement.
Should I pick 5 or 6 in?
The same size as your oval duct. The round end matches that size; check with us if your round branch is another diameter.
Can you install it?
Yes. We build risers and their connections on our installations across Greater Montréal.
Oval-to-round connections done right
Tell us the size and the quantity: we confirm availability and send you a quote. Or let our technicians install it for you.
Specifications from the manufacturer’s documentation, checked on October 7, 2026.