90° Flat Oval Elbow (Oval Duct)
The 90° oval elbow that turns square while staying flat, to follow a ceiling or floor.
AirGreen codeAG-VC-02101
514 316-2973 · sales@airgreen.ca
Quick facts
The 90° flat oval elbow turns an oval duct at a right angle while staying in the same plane. Unlike a vertical elbow, it does not raise or lower the duct: it keeps it flat, which matters in a ceiling or floor where every inch of height counts.
The turn for shallow ceilings
In a finished basement, a condo or a renovation where the ceiling cannot come down, oval duct often runs flat between the joists or under a slab. When it has to change direction, a round elbow or a vertical elbow would stick out. The flat elbow turns within the depth the duct already takes up and keeps the ceiling intact. It is a common part on air exchanger networks that serve distant rooms.
Two sizes
Offered in 5 and 6 in, for oval ducts of the same size. Both ends are oval.
Installation tips
- Check the clearance: a 90° turn needs a little more room than a straight duct.
- Support the duct on each side of the elbow so the joints are not under strain.
- Screw and seal both joints with aluminum tape or mastic before closing up.
- For a gentler turn, two 45° flat elbows separated by a short length of duct also do the job.
Installed by AirGreen across Greater Montréal
We install oval ducts in tight spaces in Montréal, Laval, Longueuil, the South Shore and 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.
Turning without gaining height
In a shallow ceiling, an oval duct sometimes has to turn square without gaining an inch of height: that is the flat elbow’s job.
- 90° turn of an oval duct laid flat in a ceiling or floor
- Changing direction to follow a joist or a beam
- Air exchanger routes in a low ceiling
- Linking two neighbouring cavities
2 sizes, one page
Each size has its own AirGreen code. Tap a row to select it.
Oval duct size.
Specifications
From the manufacturer’s documentation. A value the manufacturer does not publish is not listed.
What to know before installing
- Choose the same size as the oval duct.
- To make the duct rise or drop, use the vertical elbow instead.
- Check the clearance in the cavity before fastening the elbow.
- Screw and seal both joints.
You may also need
45° Flat Oval Elbow (Oval Duct)
Oval 90° Vertical Elbow (Oval Duct)
Galvanized Oval Duct – 60 in Length
Oval Ceiling Boot (Oval Duct)
Galvanized Round End Cap
Cleats for Galvanized Duct (C and S)
90° Oval-to-Round Elbow (Oval Duct)
Adjustable Galvanized Round 90° ElbowVentilation ductsSee all
Frequently asked questions
What does “flat elbow” mean?
An elbow that changes direction while staying in the same plane as the duct, without making it rise or drop.
Where is it used most?
In shallow ceilings and floors, when an oval duct laid flat has to turn.
Does it need sealing?
Yes. Screw both joints and seal them with foil tape or mastic before closing the ceiling.
Can you install it?
Yes. We run oval duct through tight spaces across Greater Montréal.
Discreet turns in your ceilings
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.