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    95 Products

    Ready-to-Connect Drop-Ceiling Diffusers

    No additional fittings or collars needed—connect to round duct with the included collar. These diffusers fit in the grid of a drop ceiling to evenly disperse airflow and maintain a consistent temperature throughout the space.
    For Ceiling
    Tile, ft.
    For Duct
    Size
    Wd.
    Lg.
    OD
    Gender
    Diffuser
    Shape
    Material
    Color
    Back Panel
    Material
    Louvered
    Diffuser Type
    Includes
    Each
    Louvered Diffusers
    Image of Product. Front orientation. Diffusers. Ready-to-Connect Drop-Ceiling Diffusers, Louvered Diffusers.
    6225 7/8"MaleSquarePainted SteelWhiteSteel3 TierCollar17905K111000000
    6226"MaleSquarePainted SteelWhiteSteel2 TierCollar17905K3800000
    8227 7/8"MaleSquarePainted SteelWhiteSteel3 TierCollar17905K11200000
    8228"MaleSquarePainted SteelWhiteSteel2 TierCollar17905K3900000
    10229 7/8"MaleSquarePainted SteelWhiteSteel3 TierCollar17905K11300000
    102210"MaleSquarePainted SteelWhiteSteel2 TierCollar17905K4100000
    122211 7/8"MaleSquarePainted SteelWhiteSteel3 TierCollar17905K11400000
    122212"MaleSquarePainted SteelWhiteSteel2 TierCollar17905K4200000
    142213 7/8"MaleSquarePainted SteelWhiteSteel3 TierCollar17905K11500000
    142214"MaleSquarePainted SteelWhiteSteel2 TierCollar17905K4300000
     
    Perforated Diffusers
    Image of Product. Front orientation. Diffusers. Ready-to-Connect Drop-Ceiling Diffusers, Perforated Diffusers.
    6226"MaleSquarePainted SteelWhiteSteelCollar17905K12200000
    8228"MaleSquarePainted SteelWhiteSteelCollar17905K12300000
    102210"MaleSquarePainted SteelWhiteSteelCollar17905K12400000
    122212"MaleSquarePainted SteelWhiteSteelCollar17905K12500000
    142214"MaleSquarePainted SteelWhiteSteelCollar17905K126000000
     
    Plaque Diffusers
    Image of Product. Front orientation. Diffusers. Ready-to-Connect Drop-Ceiling Diffusers, Plaque Diffusers.
    6226"MaleSquarePainted SteelWhiteSteel1 TierCollar17905K11600000
    8228"MaleSquarePainted SteelWhiteSteel1 TierCollar17905K11700000
    102210"MaleSquarePainted SteelWhiteSteel1 TierCollar17905K11800000
    122212"MaleSquarePainted SteelWhiteSteel1 TierCollar17905K11900000
    142214"MaleSquarePainted SteelWhiteSteel1 TierCollar17905K12100000
     
    Accessories for Diffusers

    Wall/Ceiling Registers

    Image of Product. Front orientation. Registers. Wall/Ceiling Registers, One-Way Airflow.
    Image of Product. Front orientation. Registers. Wall/Ceiling Registers, Three-Way Airflow.
    Image of Product. Front orientation. Registers. Wall/Ceiling Registers, Four-Way Airflow.
    Image of Product. Front orientation. Registers. Wall/Ceiling Registers, Adjustable Airflow.

    One-Way Airflow

    Three-Way Airflow

    Four-Way Airflow

    Adjustable Airflow

    Image of Specification. Side1 orientation. Surface Mount. Wall/Ceiling Registers.

    Surface

    Mount

    Direct air coming out of HVAC systems. Adjust the damper to control airflow.
    Adjustable Airflow—Adjustable airflow registers have fins that can be turned to alter the airflow direction.
    For
    Opening
    Faceplate
    White Painted Steel
    Frame and Blade
    Wd.
    Ht.
    Wd.
    Ht.
    Mounting
    Profile
    Mounting Fasteners
    Included
    Each
    One-Way Airflow
    8"4"9 3/8"5 3/8"SurfaceYes18425K81000000
    10"4"11 3/8"5 3/8"SurfaceYes18425K8300000
    12"6"13 3/8"7 3/8"SurfaceYes18425K8700000
    14"6"15 3/8"7 3/8"SurfaceYes18425K8900000
     
    Three-Way Airflow
    10"4"11 3/8"5 3/8"SurfaceYes18425K6500000
    10"6"11 3/8"7 3/8"SurfaceYes18425K6700000
    12"6"13 3/8"7 3/8"SurfaceYes18425K6900000
     
    Four-Way Airflow
    10"10"11 3/8"11 3/8"SurfaceYes18425K5700000
    12"12"13 3/8"13 3/8"SurfaceYes18425K5900000
    14"14"15 3/8"15 3/8"SurfaceYes18425K7200000
    16"16"17 3/8"17 3/8"SurfaceYes18425K7400000
     
    Adjustable Airflow
    8"6"9 3/4"7 3/4"SurfaceYes18395K6200000
    10"6"11 3/4"7 3/4"SurfaceYes18395K6400000
    12"4"13 3/4"5 3/4"SurfaceYes18395K5200000
    12"6"13 3/4"7 3/4"SurfaceYes18395K6600000
    12"8"13 3/4"9 3/4"SurfaceYes18395K6800000
    14"6"15 3/4"7 3/4"SurfaceYes18395K7200000
    14"8"15 3/4"9 3/4"SurfaceYes18395K7400000
    16"4"17 3/4"5 3/4"SurfaceYes18395K7600000
    16"6"17 3/4"7 3/4"SurfaceYes18395K8300000
    16"8"17 3/4"9 3/4"SurfaceYes18395K7800000
     

    Ready-to-Connect Moisture-Resistant Drop-Ceiling Diffusers

    Image of Product. Front orientation. Diffusers. Ready-to-Connect Moisture-Resistant Drop-Ceiling Diffusers, Louvered Diffusers.

    Louvered Diffusers

    A vapor barrier provides moisture protection as these diffusers evenly disperse airflow and maintain a consistent temperature throughout the space. No additional fittings or collars needed—connect to round duct with the included collar. Diffusers fit in the grid of a drop ceiling.
    6 Insulation R Value—Diffusers with 6 insulation R value maintain temperature more effectively than diffusers with 1 insulation R value.
    Diffusers
    Diffuser
    Insulation Blankets
    For Ceiling
    Tile, ft.
    For Duct
    Size
    Wd.
    Lg.
    OD
    Gender
    Diffuser
    Shape
    Material
    Color
    Insulation
    R Value
    Each
    Each
    Louvered Diffusers
    6226"MaleSquarePainted SteelWhite117905K5400000017905K127000000
    6226"MaleSquarePainted SteelWhite617905K13100000017905K12800000
    8228"MaleSquarePainted SteelWhite117905K550000017905K12700000
    8228"MaleSquarePainted SteelWhite617905K13200000017905K12800000
    102210"MaleSquarePainted SteelWhite117905K560000017905K12700000
    102210"MaleSquarePainted SteelWhite617905K13300000017905K12800000
    122212"MaleSquarePainted SteelWhite117905K570000017905K12700000
    122212"MaleSquarePainted SteelWhite617905K13400000017905K12800000
    142214"MaleSquarePainted SteelWhite117905K1290000017905K12700000
    142214"MaleSquarePainted SteelWhite617905K13500000017905K12800000
     
    Accessories for Diffusers

    Filter-Ready Return Grilles for Drop Ceilings

    Image of Product. Front orientation. Return Grilles. Filter-Ready Return Grilles for Drop Ceilings, Painted Steel, Louvered Diffuser.
    Image of Product. Front orientation. Return Grilles. Filter-Ready Return Grilles for Drop Ceilings, Painted Steel, Perforated Diffuser.

    Painted Steel

    Louvered Diffuser

    Painted Steel

    Perforated Diffuser

    Place these grilles in the grid of a drop ceiling to create return airflow to your HVAC system without a duct. Add a filter (not included) for protection against dust and debris.
    For Ceiling
    Tile, ft.
    For
    Filter
    Diffuser
    Type
    Wd.
    Lg.
    Color
    Trade
    Size
    Thk.
    Mounting
    Location
    Each
    Painted Steel
    Louvered22White20 × 201"Ceiling2532K7000000
    Perforated22White20 × 201"Ceiling2532K500000
     

    Ready-to-Connect Ceiling Diffusers

    Image of Product. Front orientation. Diffusers. Ready-to-Connect Ceiling Diffusers, Round Diffuser.
    Image of Product. Front orientation. Diffusers. Ready-to-Connect Ceiling Diffusers, Square Diffuser.

    Round Diffuser

    Square Diffuser

    Diffusers come with a collar and damper already in place for simple installation. They evenly disperse airflow into a room to maintain a consistent temperature throughout the space. Collar is adjustable to fit a range of duct sizes.
    Made of plastic, these diffusers are impact, abrasion, and chemical resistant.
    Overall
    For Duct
    Size
    Dia.
    Lg.
    Wd.
    Diffuser
    Shape
    Material
    Color
    Mounting Fasteners
    Included
    Each
    6, 7, 811 1/4"11 1/4"SquarePlasticWhiteYes2559K5000000
    6, 7, 812 1/8"RoundPlasticWhiteYes2559K900000
     

    Drop-Ceiling Diffuser Dampers

    Image of Product. Front orientation. Diffuser Dampers. Butterfly Opening/Closing Style.

    Butterfly

    Opening/Closing

    Style

    Image of Product. Front orientation. Diffuser Dampers. Radial Opening/Closing Style.

    Radial Opening/Closing

    Style

    For use with drop-ceiling diffusers and ready-to-connect drop-ceiling diffusers, these dampers regulate airflow. Dampers mount to a collar.
    Butterfly Opening/Closing Style—Dampers with a butterfly opening/closing style open on a middle hinge. The removable handle adjusts the damper to control airflow and is easier to adjust than dampers with a radial opening/closing style.
    Radial Opening/Closing Style—Dampers with a radial opening/closing style open in a circle for more precise airflow than dampers with a butterfly opening/closing style.
    For Duct
    Size
    Material
    Each
    Butterfly Opening/Closing Style
    6Galvanized Steel18525K81000000
    8Galvanized Steel18525K8200000
    10Galvanized Steel18525K8300000
    12Galvanized Steel18525K8400000
    14Galvanized Steel18525K8500000
     
    Radial Opening/Closing Style
    6Galvanized Steel18525K11100000
    8Galvanized Steel18525K11200000
    10Galvanized Steel18525K11300000
    12Galvanized Steel18525K11400000
    14Galvanized Steel18525K11500000
     

    Air Diverters

    Guide air toward your workspace or deflect unwanted drafts with these diverters and covers. They fit over HVAC vents, diffusers, and registers to direct hot and cold air.
    Ceiling, Side Diverters
    Image of ProductInUse. Front orientation. Air Diverters. Ceiling, Side Diverters.
    Diverters direct air without restricting flow.
    Slide In—Slide-in-mount diverters fit between your diffuser and a drop ceiling grid.
    For Ceiling
    Tile, ft.
    Wd.
    Lg.
    Lg.
    Wd.
    Dp.
    Material
    Color
    Each
    Slide In
    2223 3/4"12"2 1/2"PolystyreneWhite3531N11000000
     
    Ceiling, Corner Diverters
    Image of ProductInUse. Front orientation. Air Diverters. Ceiling, Corner Diverters.
    Diverters direct air without restricting flow.
    Slide In—Slide-in-mount diverters fit between your diffuser and a drop ceiling grid.
    For Ceiling
    Tile, ft.
    Wd.
    Lg.
    Lg.
    Wd.
    Dp.
    Material
    Color
    Each
    Slide In
    2222 1/4"22 1/4"2 1/2"PolystyreneWhite3531N12000000
     

    Ceiling Diffusers

    Image of Product. Front orientation. Diffusers. Ceiling Diffusers.
    Image of Product. Front orientation. Diffuser Collars. Ceiling Diffusers.
    Image of Product. Front orientation. Diffuser Collars. Ceiling Diffusers, Diffuser Collars with Airflow Damper.

    Diffuser Collars

    Diffuser Collars

    with Airflow Damper

    Evenly disperse airflow into a room to maintain a consistent temperature throughout the space.
    Diffuser Collars—Diffuser collars connect diffusers to duct. They are sold separately.
    Diffuser Collars with Airflow Damper—Diffuser collars with airflow damper connect diffusers to duct. They are sold separately and adjust to control airflow.
    Diffusers
    Diffuser Collars
    Diffuser Collars with
    Airflow Damper
    For Duct
    Size
    Overall
    Dia.
    Diffuser
    Shape
    Material
    Color
    Mounting Fasteners
    Included
    Each
    Each
    Each
    610"RoundPainted SteelWhiteYes1988K310000001988K410000001988K35000000
    812"RoundPainted SteelWhiteYes1988K32000001988K42000001988K3600000
    1014"RoundPainted SteelWhiteYes1988K33000001988K43000001988K3700000
    1216"RoundPainted SteelWhiteYes1988K29000001988K44000001988K3900000
    1418"RoundPainted SteelWhiteYes1988K34000001988K46000001988K4500000
     

    Drop-Ceiling Diffusers

    Image of Product. Front orientation. Diffusers. Drop-Ceiling Diffusers, Grid Diffusers.

    Grid Diffusers

    Image of Product. Front orientation. Diffusers. Drop-Ceiling Diffusers, Perforated Diffusers.

    Perforated Diffusers

    Place these diffusers in the grid of a drop ceiling to evenly disperse airflow and maintain consistent temperature throughout the space. Connect to round duct with a diffuser collar (not included).
    Grid Diffusers—Grid diffusers are often used with cooling systems. They disperse a thin layer of air along the ceiling for even distribution.
    Perforated Diffusers—Perforated diffusers have more openings than grid diffusers to release more air.
    Diffusers
    Replacement
    Diffuser Faces
    For Ceiling
    Tile, ft.
    For Duct
    Size
    Wd.
    Lg.
    Diffuser
    Shape
    Material
    Color
    Back Panel
    Material
    Insulation
    R Value
    Each
    Each
    Grid Diffusers
    6, 8, 10, 1222SquarePainted SteelWhiteFiberglass61837K450000001837K47000000
     
    Perforated Diffusers
    6, 8, 10, 1222SquarePainted SteelWhiteFiberglass61837K21000001837K2200000
     
    Accessories for Diffusers

    Snap-On Drop-Ceiling Diffuser Collars

    Image of Product. Front orientation. Diffuser Collars.
    Connect drop-ceiling diffusers to duct. Use the included push-in fasteners to attach collar to diffuser.
    For Duct
    Size
    OD
    Gender
    Material
    Each
    65 15/16"MaleGalvanized Steel18525K44000000
    87 15/16"MaleGalvanized Steel18525K4500000
    109 15/16"MaleGalvanized Steel18525K4600000
    1211 15/16"MaleGalvanized Steel18525K4700000

    Moisture-Resistant Drop-Ceiling Diffusers

    Image of Product. Front orientation. Diffusers. Moisture-Resistant Drop-Ceiling Diffusers, Grid Diffusers.

    Grid Diffusers

    Image of Product. Front orientation. Diffusers. Moisture-Resistant Drop-Ceiling Diffusers, Perforated Diffusers.

    Perforated Diffusers

    A vapor barrier provides moisture protection as these diffusers evenly disperse airflow and maintain a consistent temperature throughout the space. They fit in the grid of a drop ceiling. Connect to round duct with a diffuser collar (not included).
    Grid Diffusers—Grid diffusers are often used with cooling systems. They disperse a thin layer of air along the ceiling for even distribution.
    Perforated Diffusers—Perforated diffusers have more openings than grid diffusers to release more air.
    Diffusers
    Replacement
    Diffuser Faces
    For Ceiling
    Tile, ft.
    For Duct
    Size
    Wd.
    Lg.
    Diffuser
    Shape
    Material
    Color
    Back Panel
    Material
    Insulation
    R Value
    Each
    Each
    Grid Diffusers
    6, 8, 10, 1222SquarePainted SteelWhiteSteel61837K4600000001837K47000000
     
    Perforated Diffusers
    6, 8, 10, 1222SquarePainted SteelWhiteSteel61837K230000001837K2200000
     
    Accessories for Diffusers
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