Return Air Grilles
20x20 return air grille
| Brand | shengtongJH |
|---|---|
| Nominal opening W × H | 20 × 20 in / 508 × 508 mm |
| Related opening choices | 18 × 18 or 24 × 24 in by air-system selection |
| Face | Fixed inclined horizontal blades |
| Materials | Powder-coated steel or aluminium |
| Border | Surface-mounted flange with drawing-defined overlap |
| Core arrangement | Fixed or removable centre |
| Filtration | Separate filter rack only where specified |
| Fixing | Frame screws into suitable supporting material |
| Finish | White or selected coating |
| Air duty | Return airflow selected using free area and allowable sound/pressure loss |
The nominal opening is not a guaranteed overall face or filter size. Confirm the selected construction drawing before forming the opening.
Frame overlap, core access, material and finish can be customized to the square return opening and connected air system.
A 20x20 return air grille covers a nominal square return opening. The size describes the intended opening convention, so the visible outer frame and any filter behind it need their own dimensional checks.
Coordinate the square opening before cutting
A square grille is straightforward to set out, but the frame still needs sound material around the opening. Align the return plenum and surrounding wall or ceiling support so the flange can sit flat without being used to pull an uneven opening into shape.
Use the selected frame drawing to establish the final cut-out. An installer measuring only the outer face can create an opening too large for the flange to cover. Conversely, a hole based on an unrelated filter label may prevent the rear neck from entering.
Behind the face
The plenum or branch should let air reach the opening without a sharp obstruction directly behind the blades. A large face attached to a very restricted rear connection does not remove the upstream bottleneck.
At the border
Check clearance to ceiling trims, wall joints and service panels. Even a square core can have directional blade sightlines or a preferred release edge, so include orientation on the installation drawing.
During cleaning
A removable centre can provide useful access to the return void. Decide whether the whole frame or only the core should be removed for normal service, then select the fastening accordingly.
Size against the operating condition
Provide the required return airflow and the acceptable pressure loss or sound criterion with the enquiry. The nominal opening is a geometric input, not a guaranteed capacity. If filtration is added behind the grille, include its clean and loaded resistance in the system review rather than assuming an unfiltered selection remains suitable.
Frame overlap, core access, material and finish can be customized to the square return opening and connected air system.